Merge pull request 'LiveKit integration: real camera feed pipeline' (#1) from feat/livekit-integration into main

.gitea/workflows/build.yml

@@ -1,8 +1,23 @@
 name: Build
 
-# Scaffolding CI: proves the CMake toolchain configures and builds on all
+# Every job builds the real plugin: the core library linked against the
-# three platforms the design doc names. It does not yet link livekit-ffi
+# pinned livekit/client-sdk-cpp release, and -- where libobs is available --
-# or produce a real OBS-installable package -- see README.md.
+# the OBS adapter module itself.
+#
+# Linux gets libobs from Ubuntu's libobs-dev. macOS and Windows have no
+# equivalent system package, so they run obs-plugintemplate's buildspec
+# bootstrap (buildspec.json + cmake/common/buildspec_common.cmake), which
+# downloads the pinned obs-deps bundle and obs-studio source and builds just
+# `libobs`. That step is the slow one: several minutes on a cold runner.
+#
+# RELEASE GATE: this workflow only builds, tests, and uploads CI-internal
+# workflow artifacts (actions/upload-artifact, below) -- it does not create a
+# Gitea Release, push a tag-triggered publish, or otherwise distribute
+# binaries publicly, and it must not start doing so without explicit owner
+# sign-off on the WebRTC/OpenH264 attribution and GPLv2/Apache-2.0
+# license-compatibility questions tracked in third_party/livekit/README.md
+# and the README's top-level Status section. If a real release/publish step
+# is ever added here, it must carry that same gate.
 
 on:
   push:
@@ -10,8 +25,13 @@ on:
 
 jobs:
   linux:
-    name: Linux (ubuntu-latest)
+    name: Linux (ubuntu-24.04)
-    runs-on: ubuntu-latest
+    # Pinned to 24.04 rather than ubuntu-latest, which this instance's two
+    # Linux runners answer with different releases. 24.04's libobs-dev is
+    # 30.0.2, exactly the OBS version buildspec.json pins for macOS/Windows,
+    # so all three platforms build against the same libobs. On a 22.04 runner
+    # libobs-dev is OBS 27, which is a different API surface entirely.
+    runs-on: ubuntu-24.04
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -19,10 +39,12 @@ jobs:
       - name: Install build dependencies
         run: |
           sudo apt-get update -qq
-          sudo apt-get install -y -qq cmake ninja-build libobs-dev
+          sudo apt-get install -y -qq cmake ninja-build libobs-dev libcurl4-openssl-dev
 
       - name: Configure
-        run: cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
+        # Linux keeps its distribution libobs; the buildspec bootstrap is for
+        # the two platforms that have no such package.
+        run: cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DSTPLUGIN_BOOTSTRAP_OBS=OFF
 
       - name: Build
         run: cmake --build build
@@ -30,6 +52,19 @@ jobs:
       - name: Test (core library)
         run: ctest --test-dir build --output-on-failure
 
+      - name: Show what was built
+        run: |
+          ls -la build/package/bin/64bit build/package/data/locale build/package/licenses
+          ldd build/package/bin/64bit/streamer-tools-camera.so | grep -E 'obs|livekit'
+          nm -D build/package/bin/64bit/streamer-tools-camera.so | grep -E ' T obs_module_(load|unload)'
+
+      - name: Upload plugin
+        continue-on-error: true
+        uses: actions/upload-artifact@v3
+        with:
+          name: streamer-tools-camera-linux-x64
+          path: build/package
+
   macos:
     name: macOS (macos-latest)
     runs-on: macos-latest
@@ -41,11 +76,21 @@ jobs:
         run: brew install cmake ninja
 
       - name: Configure
-        # libobs is not expected to be found here yet (no Homebrew
+        # The buildspec bootstrap runs here: it fetches obs-deps + the pinned
-        # formula / SDK download wired up in this pass) -- the top-level
+        # obs-studio source and builds libobs before this project configures.
-        # CMakeLists.txt falls back to building only the core library in
+        #
-        # that case. See README.md.
+        # If that fails, fall back to a core-library-only build rather than
-        run: cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
+        # going red: the core library and its tests are what this job mainly
+        # guards, and the fallback is loud (a workflow warning, plus the
+        # "Show what was built" step below reporting no module) rather than
+        # silent. Do not remove the warning -- a green job that quietly stopped
+        # building the plugin is worse than a red one.
+        run: |
+          if ! cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release; then
+            echo "::warning::OBS SDK bootstrap failed on macOS; building the core library only. The plugin module was NOT built."
+            rm -rf build
+            cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DSTPLUGIN_BOOTSTRAP_OBS=OFF
+          fi
 
       - name: Build
         run: cmake --build build
@@ -53,6 +98,19 @@ jobs:
       - name: Test (core library)
         run: ctest --test-dir build --output-on-failure
 
+      - name: Show what was built
+        run: |
+          ls -la .deps/Frameworks/libobs.framework/Resources/cmake || true
+          ls -la build/package/bin || true
+          otool -L build/package/bin/streamer-tools-camera.so || true
+
+      - name: Upload plugin
+        continue-on-error: true
+        uses: actions/upload-artifact@v3
+        with:
+          name: streamer-tools-camera-macos
+          path: build/package
+
   windows:
     name: Windows (windows-latest)
     runs-on: windows-latest
@@ -61,22 +119,46 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install build dependencies
-        # winvm-builder is a self-hosted act_runner labeled
+        # winvm-builder is a self-hosted act_runner labeled "windows-latest";
-        # "windows-latest" -- it is NOT the GitHub-hosted windows-latest
+        # it is NOT the GitHub-hosted image, so none of that image's
-        # image, so none of the tools that image preinstalls (cmake
+        # preinstalled tooling (cmake included) can be assumed present.
-        # included) can be assumed present. Confirmed by a first CI run
-        # on this repo: "cmake : The term 'cmake' is not recognized...".
-        # lukka/get-cmake downloads a pinned cmake+ninja binary and adds
-        # it to PATH for this job, with no admin/choco dependency.
         uses: lukka/get-cmake@latest
 
       - name: Configure
-        # Same story as macOS: no OBS SDK available yet on this runner,
+        # The default Visual Studio generator is required, not Ninja:
-        # so this proves the core library + MSVC toolchain only.
+        # cmake/windows/buildspec.cmake keys the dependency slice off
-        run: cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
+        # CMAKE_VS_PLATFORM_NAME, which only a VS generator sets.
+        #
+        # Same fallback as macOS, and the same warning: a green job that
+        # quietly stopped building the plugin is worse than a red one.
+        # PowerShell, not bash: this runner is a plain Windows VM and bash
+        # cannot be assumed present.
+        run: |
+          cmake -S . -B build -A x64
+          if ($LASTEXITCODE -ne 0) {
+            Write-Host "::warning::OBS SDK bootstrap failed on Windows; building the core library only. The plugin module was NOT built."
+            Remove-Item -Recurse -Force build -ErrorAction SilentlyContinue
+            cmake -S . -B build -A x64 -DSTPLUGIN_BOOTSTRAP_OBS=OFF
+            if ($LASTEXITCODE -ne 0) { exit 1 }
+          }
 
       - name: Build
         run: cmake --build build --config Release
 
       - name: Test (core library)
         run: ctest --test-dir build -C Release --output-on-failure
+
+      - name: Show what was built
+        run: |
+          if (Test-Path build\package\bin\64bit) {
+            Get-ChildItem build\package\bin\64bit
+          } else {
+            Write-Host "no plugin module was built (core library only)"
+          }
+
+      - name: Upload plugin
+        continue-on-error: true
+        uses: actions/upload-artifact@v3
+        with:
+          name: streamer-tools-camera-windows-x64
+          path: build/package

.gitignore

@@ -1,2 +1,6 @@
 build/
+build*/
 .cache/
+# obs-plugintemplate's buildspec bootstrap unpacks the OBS SDK and its
+# prebuilt dependencies here (macOS/Windows only).
+.deps/

CMakeLists.txt

@@ -1,8 +1,8 @@
-cmake_minimum_required(VERSION 3.16)
+cmake_minimum_required(VERSION 3.19)
 
 project(obs-streamer-tools-plugin
-    VERSION 0.0.1
+    VERSION 0.1.0
-    DESCRIPTION "OBS Studio source plugin for streamer-tools camera feeds (scaffold, no LiveKit integration yet)"
+    DESCRIPTION "OBS Studio source plugin for streamer-tools camera feeds"
     LANGUAGES C CXX
 )
 
@@ -11,23 +11,184 @@ set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+    set(CMAKE_BUILD_TYPE Release CACHE STRING "Build type" FORCE)
+endif()
+
 enable_testing()
 
-# --- Scaffolding note ------------------------------------------------------
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
-# This deliberately does NOT use the full obsproject/obs-plugintemplate
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/common")
-# build system (its cmake/common/bootstrap.cmake + buildspec.json, which
+
-# download complete OBS source archives and prebuilt dependency bundles
+# --- OBS SDK ---------------------------------------------------------------
-# for macOS/Windows). That machinery is real and may be worth adopting
+# Linux gets libobs from the distribution (Ubuntu's libobs-dev ships real
-# wholesale in a later phase; for this scaffolding pass the goal is a much
+# libobsConfig.cmake), and that path is left exactly as it was.
-# simpler CMakeLists.txt that proves out find_package(libobs) plus the
+#
-# core/adapter split on the platform we can actually verify locally
+# macOS and Windows have no such package, so they use obs-plugintemplate's
-# (Linux, via the system libobs-dev package). See README.md for the full
+# buildspec bootstrap, trimmed: it downloads the pinned obs-deps bundle and
-# writeup of what was verified vs. what remains.
+# the pinned obs-studio source, then builds and installs just `libobs`. See
-# ----------------------------------------------------------------------------
+# buildspec.json for why the OBS pin is deliberately low, and
+# cmake/common/buildspec_common.cmake for every change from upstream.
+#
+# STPLUGIN_BOOTSTRAP_OBS=OFF falls back to plain find_package(libobs), for a
+# developer who already has an OBS SDK on their prefix path and does not want
+# a from-source libobs build.
+option(STPLUGIN_BOOTSTRAP_OBS "Download and build libobs from source (macOS/Windows)" ON)
+
+# Fallbacks for imported targets that were exported under a different
+# configuration name than the one being built, lifted from
+# obs-plugintemplate's cmake/common/bootstrap.cmake. Without these, an
+# imported libobs exported as (say) RelWithDebInfo fails a Release build with
+# "IMPORTED_LOCATION or IMPORTED_IMPLIB not set for imported target
+# OBS::libobs configuration Release".
+set(CMAKE_MAP_IMPORTED_CONFIG_RELEASE Release RelWithDebInfo MinSizeRel None "")
+set(CMAKE_MAP_IMPORTED_CONFIG_RELWITHDEBINFO RelWithDebInfo Release MinSizeRel None "")
+set(CMAKE_MAP_IMPORTED_CONFIG_MINSIZEREL MinSizeRel Release RelWithDebInfo None "")
+set(CMAKE_MAP_IMPORTED_CONFIG_DEBUG Debug RelWithDebInfo Release MinSizeRel None "")
+
+include(osconfig)
+if(STPLUGIN_BOOTSTRAP_OBS AND (OS_MACOS OR OS_WINDOWS))
+    if(OS_MACOS)
+        # client-sdk-cpp ships single-arch dylibs, so this plugin is built for
+        # one architecture even though the libobs it links is universal.
+        if(NOT CMAKE_OSX_ARCHITECTURES)
+            set(CMAKE_OSX_ARCHITECTURES "${CMAKE_HOST_SYSTEM_PROCESSOR}" CACHE STRING "" FORCE)
+        endif()
+        if(NOT CMAKE_OSX_DEPLOYMENT_TARGET)
+            set(CMAKE_OSX_DEPLOYMENT_TARGET "13.0" CACHE STRING "" FORCE)
+        endif()
+    endif()
+    include(buildspec)
+endif()
+
+# --- LiveKit C++ client SDK -------------------------------------------------
+# Pinned, prebuilt release of livekit/client-sdk-cpp, downloaded and unpacked
+# by cmake/LiveKitSDK.cmake, then consumed through its own CMake package
+# config as the LiveKit::livekit imported target. See the design doc's
+# "Resolved (2026-09-07)" section: an exact pin, never "latest".
+set(STPLUGIN_LIVEKIT_SDK_VERSION "1.10.1" CACHE STRING
+    "Pinned livekit/client-sdk-cpp release version")
+set(STPLUGIN_LIVEKIT_SDK_TRIPLE "" CACHE STRING
+    "Override the client-sdk-cpp release triple (e.g. ubuntu-24.04-x64); empty = autodetect")
+set(STPLUGIN_LIVEKIT_SDK_DIR "${CMAKE_BINARY_DIR}/_deps/livekit-sdk" CACHE PATH
+    "Directory the client-sdk-cpp release archive is extracted into (point at a persistent path to cache it across CI builds)")
+
+# Pinned SHA256 checksums for the client-sdk-cpp v1.10.1 release archives,
+# so the download in cmake/LiveKitSDK.cmake is verified the same way the
+# obs-deps bootstrap next to it already is (see
+# cmake/common/buildspec_common.cmake ~line 324). Each hash below was
+# computed by downloading the real GitHub release asset and running
+# `sha256sum` on it (2026-09-06/07) -- none of these were guessed or copied
+# from an unverified source. To add a hash for a new version or triple:
+#   curl -LO https://github.com/livekit/client-sdk-cpp/releases/download/v<VERSION>/livekit-sdk-<TRIPLE>-<VERSION>.<tar.gz|zip>
+#   sha256sum livekit-sdk-<TRIPLE>-<VERSION>.*
+# Covers every triple _lk_default_triple() can resolve to for this pinned
+# version: Linux (ubuntu-22.04-x64/arm64), macOS (macos-x64/arm64) and
+# Windows (windows-x64). Verified by extracting each archive
+# (tar tzf / unzip -l) and confirming a real LiveKitConfig.cmake inside --
+# only Linux was also verified by an actual local CMake configure+build in
+# this environment; macOS and Windows were downloaded and hashed but not
+# build-tested here.
+set(_stplugin_livekit_sha256_1.10.1_ubuntu-22.04-x64   "6f4fc8143f36952d42bfd5ff8d1782cf6211ba8fd6b055877e9ef85441d66324")
+set(_stplugin_livekit_sha256_1.10.1_ubuntu-22.04-arm64 "399677167b474b7f107c6937904ea01898c9ec8da648cbed669387e599c6ea45")
+set(_stplugin_livekit_sha256_1.10.1_macos-x64          "7102655c1f2947be4b06a95f9fafa1a11379219328e82ad875e5ebccfc9ac7e3")
+set(_stplugin_livekit_sha256_1.10.1_macos-arm64        "0822af7014519a473c5b5cd019bde58c26cc2bfe5b78e4a790395ead232dc55b")
+set(_stplugin_livekit_sha256_1.10.1_windows-x64        "b9fc6b2865298d7e3d032205d7e74fb9628cfe55a2ed28cb657db0a481cd518c")
+
+include(LiveKitSDK)
+if(STPLUGIN_LIVEKIT_SDK_TRIPLE)
+    set(_stplugin_livekit_triple "${STPLUGIN_LIVEKIT_SDK_TRIPLE}")
+else()
+    # Mirrors LiveKitSDK.cmake's own autodetection so the checksum lookup
+    # below matches whatever triple livekit_sdk_setup() will actually
+    # resolve to and download.
+    _lk_default_triple(_stplugin_livekit_triple)
+endif()
+
+set(_stplugin_livekit_sha256_var
+    "_stplugin_livekit_sha256_${STPLUGIN_LIVEKIT_SDK_VERSION}_${_stplugin_livekit_triple}")
+if(DEFINED ${_stplugin_livekit_sha256_var})
+    set(_stplugin_livekit_sha256 "${${_stplugin_livekit_sha256_var}}")
+else()
+    set(_stplugin_livekit_sha256 "")
+    message(WARNING
+        "LiveKitSDK: no pinned SHA256 for triple '${_stplugin_livekit_triple}' "
+        "at version ${STPLUGIN_LIVEKIT_SDK_VERSION} -- the downloaded archive "
+        "will NOT be integrity-checked. Compute one (see the comment above "
+        "this block) and add it to CMakeLists.txt.")
+endif()
+
+if(STPLUGIN_LIVEKIT_SDK_TRIPLE)
+    livekit_sdk_setup(
+        VERSION "${STPLUGIN_LIVEKIT_SDK_VERSION}"
+        SDK_DIR "${STPLUGIN_LIVEKIT_SDK_DIR}"
+        TRIPLE "${STPLUGIN_LIVEKIT_SDK_TRIPLE}"
+        SHA256 "${_stplugin_livekit_sha256}"
+    )
+else()
+    livekit_sdk_setup(
+        VERSION "${STPLUGIN_LIVEKIT_SDK_VERSION}"
+        SDK_DIR "${STPLUGIN_LIVEKIT_SDK_DIR}"
+        SHA256 "${_stplugin_livekit_sha256}"
+    )
+endif()
+find_package(LiveKit CONFIG REQUIRED)
 
 add_subdirectory(core)
 
 find_package(libobs QUIET)
+
+# The imported OBS::libobs target can come back without a location. OBS 30.0.2
+# installs libobsTargets.cmake but not the per-configuration
+# libobsTargets-<config>.cmake alongside it when libobs is built on its own,
+# and CMake then fails at generate time with:
+#
+#   IMPORTED_LOCATION or IMPORTED_IMPLIB not set for imported target
+#   "OBS::libobs" configuration "Release".
+#
+# Repair it here rather than fighting OBS's export machinery: the library the
+# bootstrap just built is in a known place, and pointing the imported target
+# at it is exactly what the missing file would have done. Distribution
+# packages (Ubuntu's libobs-dev) export a complete target and never take this
+# path.
+if(libobs_FOUND AND TARGET OBS::libobs)
+    get_target_property(_stplugin_obs_location OBS::libobs IMPORTED_LOCATION)
+    get_target_property(_stplugin_obs_location_release OBS::libobs IMPORTED_LOCATION_RELEASE)
+    get_target_property(_stplugin_obs_implib OBS::libobs IMPORTED_IMPLIB)
+    get_target_property(_stplugin_obs_implib_release OBS::libobs IMPORTED_IMPLIB_RELEASE)
+    if(NOT _stplugin_obs_location
+       AND NOT _stplugin_obs_location_release
+       AND NOT _stplugin_obs_implib
+       AND NOT _stplugin_obs_implib_release)
+        set(_stplugin_deps "${CMAKE_CURRENT_SOURCE_DIR}/.deps")
+        if(APPLE)
+            set(_stplugin_obs_binary "${_stplugin_deps}/Frameworks/libobs.framework/Versions/A/libobs")
+            if(NOT EXISTS "${_stplugin_obs_binary}")
+                set(_stplugin_obs_binary "${_stplugin_deps}/Frameworks/libobs.framework/libobs")
+            endif()
+            if(EXISTS "${_stplugin_obs_binary}")
+                set_target_properties(
+                    OBS::libobs
+                    PROPERTIES
+                        IMPORTED_LOCATION "${_stplugin_obs_binary}"
+                        INTERFACE_INCLUDE_DIRECTORIES "${_stplugin_deps}/Frameworks/libobs.framework/Headers"
+                )
+                message(STATUS "OBS::libobs had no imported location; pointed it at ${_stplugin_obs_binary}")
+            endif()
+        elseif(WIN32)
+            find_file(_stplugin_obs_implib_found obs.lib PATHS "${_stplugin_deps}/lib" NO_DEFAULT_PATH)
+            find_file(_stplugin_obs_dll_found obs.dll PATHS "${_stplugin_deps}/bin" NO_DEFAULT_PATH)
+            if(_stplugin_obs_implib_found)
+                set_target_properties(OBS::libobs PROPERTIES IMPORTED_IMPLIB "${_stplugin_obs_implib_found}")
+                if(_stplugin_obs_dll_found)
+                    set_target_properties(OBS::libobs PROPERTIES IMPORTED_LOCATION "${_stplugin_obs_dll_found}")
+                endif()
+                message(STATUS "OBS::libobs had no imported location; pointed it at ${_stplugin_obs_implib_found}")
+            endif()
+        endif()
+    endif()
+endif()
+
 if(libobs_FOUND)
     message(STATUS "libobs found (${libobs_DIR}) -- building OBS adapter module")
     add_subdirectory(obs-adapter)

README.md

@@ -1,159 +1,340 @@
 # obs-streamer-tools-plugin
 
-Native OBS Studio source plugin that will pull streamer-tools camera feeds
+Native OBS Studio source plugin that pulls streamer-tools camera feeds
-directly from LiveKit over WebRTC (via LiveKit's `livekit-ffi`), replacing
+directly from LiveKit over WebRTC, replacing the current SRT/RTSP-via-VLC-or-
-the current SRT/RTSP-via-VLC-or-Media-Source path for directors. Full
+Media-Source path for directors. Full design:
-design: `docs/superpowers/specs/2026-09-06-obs-camera-plugin-design.md` in
+`docs/superpowers/specs/2026-09-06-obs-camera-plugin-design.md` in the
-the `streamer-tools` repo (as of this writing, that doc lives on the
+`streamer-tools` repo.
-`worktree-obs-plugin-server-api` branch there, not yet merged to `main`).
 
-## Status: scaffolding only
+## Status
 
-**This repository does not talk to LiveKit or streamer-tools yet.** This
+**Release/distribution of built binaries is blocked pending owner sign-off.**
-first pass exists to prove the CMake toolchain, the core-library/OBS-adapter
+This plugin statically/dynamically pulls in Google WebRTC and OpenH264 code
-split, and the three-platform Gitea Actions CI pipeline all actually work,
+through the LiveKit SDK, and this repository's own top-level `LICENSE` is
-so the next phase (real `livekit-ffi` integration) can be planned against
+GPLv2 while the vendored LiveKit binaries are Apache-2.0 — both a real patent/
-verified facts instead of assumptions. See the design doc's "Components"
+royalty question (OpenH264/WebRTC) and a real license-compatibility question
-and "CI / build pipeline" sections for the target architecture this scaffold
+(GPLv2 vs. Apache-2.0-linked code) that only the project owner can decide.
-is standing up.
+Nothing in this repo should be built into a package and handed out, posted,
+or attached to a public release until that sign-off happens. See
+`third_party/livekit/README.md` for the specifics of what is and is not
+currently known/shipped on the licensing side. (CI in `.gitea/workflows/build.yml`
+currently only builds, tests, and uploads CI-internal build artifacts — it
+does not create a Gitea Release or otherwise publish anything publicly; if
+that ever changes, the new step must carry this same gate.)
+
+The plugin is **functionally complete on Linux and verified end to end there**
+(module loads into real libobs, connects to a real LiveKit server through the
+real streamer-tools API shape, and pushes decoded frames into
+`obs_source_output_video`/`_audio`).
+
+It has **not been run in the OBS GUI on any platform.** macOS builds the real
+module in CI but its artifact is not yet loadable (see the macOS packaging gap
+under CI). Windows CI has **failed on every completed run so far** (7
+consecutive failures on this branch as of this writing); a run against the
+commit with the `-A x64` argument fix is in progress but not yet complete,
+and the commit with the PowerShell rewrite of the Windows steps is still
+queued behind it. Neither fix has a completed, passing run yet. See "Where
+the Windows bootstrap got to" under CI below for the exact record, and check
+current CI status rather than trusting this paragraph's age.
+
+See "What is verified, and how" below for exactly what has and has not been
+checked, and "Testing this by hand" for what a human still needs to do.
 
 ## Layout
 
 ```
-core/           - core library (C++17, no OBS dependency, headless-testable)
+cmake/LiveKitSDK.cmake   - downloads + unpacks the pinned client-sdk-cpp release
+core/                    - core library (C++17, no OBS dependency, headless-testable)
   include/stplugin/
-    core.h        C++ API (ConnectionConfig, core_version())
+    core.h                 version + ConnectionConfig
-    core_c.h       C ABI wrapper the OBS adapter calls into
+    json.h                 small strict JSON reader
-  src/core.cpp
+    http.h                 injectable HTTP client interface
-  tests/           dependency-free CTest unit tests
+    api_client.h           the two /api/obs/:slug/* calls
-
+    session_types.h        media/state types + the pure session logic
-obs-adapter/    - thin OBS glue (C, adapted from obsproject/obs-plugintemplate)
+    session.h              LiveKitSession, the livekit::Room wrapper
-  src/plugin-main.c       obs_module_load/unload + a stub source registration
+  src/
-  src/plugin-support.{h,c.in}
+    http_curl.cpp          libcurl backend (Linux/macOS)
+    http_winhttp.cpp       WinHTTP backend (Windows)
+  tests/                   dependency-free CTest suites
+obs-adapter/             - thin OBS glue (C++)
+  src/plugin-main.cpp      obs_source_info, properties UI, frame output
   data/locale/en-US.ini
-
+scripts/livekit-dev-room.py - mints tokens for the integration test
-.gitea/workflows/build.yml   - 3-platform CI matrix (see below)
+third_party/livekit/     - redistribution notices for the LiveKit binaries
+.gitea/workflows/build.yml  - 3-platform CI matrix
 ```
 
-Everything in `core/` is real, working, unit-tested code -- it just doesn't
+## How it works
-do anything useful yet (a version string, a config struct with non-empty
-validation). Everything in `obs-adapter/` is real OBS module code -- it
-registers an actual `obs_source_info` and builds as a real, dynamically
-loadable OBS module (see "Verified" below) -- but the source is a stub:
-`create`/`destroy` allocate/free a dummy blob, there is no properties UI,
-and no frames are ever pushed. That's the boundary this task was scoped to.
 
-## What's real vs. deliberately deferred
+1. The operator fills in the streamer-tools server URL, room slug and read key,
+   and picks a camera from the dropdown.
+2. The source's own worker thread calls `POST /api/obs/:slug/token?key=…` to
+   mint a hidden, subscribe-only LiveKit token
+   (identity `obs:<slug>:<nonce>` — a fresh nonce per mint, so two OBS
+   installs watching the same room can never kick each other).
+3. `LiveKitSession` connects `livekit::Room` to the returned `wsUrl`, waits for
+   the chosen participant's `Source.Camera` video track (and their microphone),
+   and reads decoded frames off `VideoStream`/`AudioStream`.
+4. The adapter hands those straight to `obs_source_output_video` /
+   `obs_source_output_audio`.
 
-Deferred, per the task that produced this scaffold (out of scope for this
+Nothing on the OBS UI thread ever blocks on the network. The one deliberate
-pass, in scope for the next one):
+exception is the "Refresh camera list" button, which the operator pressed and
+is waiting on; it uses a shortened 5s timeout.
 
-- No `livekit-ffi` linkage of any kind.
+### Design decisions worth knowing before changing this
-- No streamer-tools API client (auth, slot-listing, token minting).
-- No properties UI (server URL / room slug / read key / camera dropdown).
-- No frame output (`obs_source_output_video`/`_audio`).
-- No packaging/release step (the design doc's "on a version tag" job).
 
-## Toolchain notes (verified on this machine: Ubuntu 24.04 / Linux)
+- **Frames come from `VideoStream::fromTrack` with our own reader threads, not
+  from `Room::setOnVideoFrameCallback`.** The dispatcher API is keyed by
+  (participant identity, track *name*), which is only knowable once the track
+  is published — and disassembly of `liblivekit.so` 1.10.1 confirms that
+  neither `Room::setOnVideoFrameCallback` nor the dispatcher's own version
+  starts a reader for an already-subscribed track; they only record the
+  registration. Registering at the only moment the name exists would therefore
+  have silently produced no video.
+- **Every stream operation runs on one owned worker thread**, never on a
+  LiveKit room event thread: `Room::disconnect()` from inside a delegate
+  callback is documented to deadlock.
+- **`VideoStream::Options::capacity` is 3**, making the SDK queue a
+  drop-oldest ring buffer. A stalled consumer can only fall three frames
+  behind and then sees the *newest* frame, not a backlog — the structural
+  answer to the stale-media bug that motivated this plugin.
+- **Video and audio are both timestamped with `os_gettime_ns()` at arrival.**
+  The SDK gives video a WebRTC capture timestamp and audio none; mixing two
+  epochs inside one OBS source would guarantee A/V drift. This relies on the
+  SDK's jitter buffering having already aligned them — the assumption the
+  design doc flags for verification on real hardware. **Still unverified.**
+- **WebRTC changes resolution mid-stream.** Observed directly in the
+  integration test: the first frames after (re)subscribing arrive at a
+  downscaled spatial layer before ramping to the published size. The adapter
+  passes each frame's own geometry through, and logs geometry changes.
 
-- **CMake 3.28.3**, **Ninja 1.11.1**, GCC 13.3.0 -- all installed via
+## Building
-  `apt-get install cmake ninja-build`. Top-level `CMakeLists.txt` requires
-  CMake >= 3.16 (deliberately lower than the official
-  obsproject/obs-plugintemplate's `3.28...3.30` floor -- see below).
-- **OBS plugin template used as reference**: obsproject/obs-plugintemplate,
-  commit `3e7d7ac3b5342cd7d9b88890b9c70b472d1520fc` (2025-12-09, "Fix typo
-  of Visual Studio in README"), fetched fresh from GitHub. `src/plugin-main.c`,
-  `src/plugin-support.{h,c.in}`, and the empty `data/locale/en-US.ini` in
-  `obs-adapter/` are adapted directly from it.
-- **Deliberate deviation from the template's own build system**: the
-  official template's `CMakeLists.txt` chains into
-  `cmake/common/bootstrap.cmake`, which in turn reads `buildspec.json` and
-  *downloads full OBS source archives (pinned to OBS 31.1.1) plus prebuilt
-  dependency bundles* for macOS and Windows. That machinery is real,
-  actively maintained, and probably the right long-term answer for
-  cross-platform reproducible builds -- but it's heavy (multi-hundred-MB
-  downloads, a whole `cmake/{macos,windows,common}` support tree, Qt6,
-  code-signing hooks) and out of scope to stand up and debug in one pass.
-  This scaffold instead uses a much simpler hand-written top-level
-  `CMakeLists.txt` that calls `find_package(libobs)` directly.
-- **On Linux, this actually works far better than expected**: Ubuntu ships
-  a real `libobs-dev` package (`30.0.2+dfsg-3build1` on 24.04, i.e. **not**
-  the 31.1.1 the template's buildspec.json pins -- worth reconciling before
-  the next phase if API surface matters) with genuine CMake package config
-  files (`/usr/lib/x86_64-linux-gnu/cmake/libobs/libobsConfig.cmake`,
-  `libobsTargets.cmake`) that export an `OBS::libobs` imported target --
-  the exact target name the official template expects. `find_package(libobs
-  QUIET)` finds it with zero extra plumbing. This means the OBS adapter in
-  this repo links against **real OBS headers and a real `libobs.so`**, not
-  a stub -- confirmed by `ldd` showing `libobs.so.0` and `nm -D` showing
-  real `obs_module_*` exports (see "Verified" below). Install via
-  `apt-get install libobs-dev` (pulls in Qt6 as a dependency chain, ~seconds
-  on a fast mirror).
-- **macOS/Windows have no equivalent system package** (there's no Homebrew
-  formula or winget package that ships `libobsConfig.cmake` the way Ubuntu's
-  `libobs-dev` does). For those platforms the choices are: (a) adopt the
-  template's full buildspec-driven source/prebuilt-deps download, or (b)
-  find/produce a lighter prebuilt SDK bundle. **This is now a concrete,
-  scoped decision for the next phase**, not a guess -- the CI workflow in
-  this repo currently takes option (c) for this pass only: skip building
-  the OBS adapter on macOS/Windows and build+test just the core library,
-  via the same `find_package(libobs QUIET)` fallback the top-level
-  `CMakeLists.txt` already has for exactly this situation.
-- **`ENABLE_QT`/`ENABLE_FRONTEND_API` template options were not carried
-  over** -- this scaffold's properties-UI-free stub doesn't need Qt yet;
-  the real adapter will need to revisit this once the properties UI
-  (server URL / room slug / read key / camera dropdown) is built.
 
-## What actually builds, and how it was verified
+Linux (the platform that is fully verified). `STPLUGIN_BOOTSTRAP_OBS=OFF`
+skips the macOS/Windows OBS-SDK bootstrap, which Linux does not need:
 
 ```
-$ cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
+sudo apt-get install -y cmake ninja-build libobs-dev libcurl4-openssl-dev
--- libobs found (/usr/lib/x86_64-linux-gnu/cmake/libobs) -- building OBS adapter module
+cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DSTPLUGIN_BOOTSTRAP_OBS=OFF
--- Configuring done
+cmake --build build
--- Generating done
+ctest --test-dir build --output-on-failure
-
-$ cmake --build build
-[1/7] Building C object obs-adapter/CMakeFiles/streamer-tools-camera.dir/plugin-support.c.o
-[2/7] Building C object obs-adapter/CMakeFiles/streamer-tools-camera.dir/src/plugin-main.c.o
-[3/7] Building CXX object core/CMakeFiles/stplugin_core.dir/src/core.cpp.o
-[4/7] Linking CXX static library core/libstplugin_core.a
-[5/7] Building CXX object core/tests/CMakeFiles/stplugin_core_tests.dir/test_core.cpp.o
-[6/7] Linking CXX shared module obs-adapter/streamer-tools-camera.so
-[7/7] Linking CXX executable core/tests/stplugin_core_tests
-
-$ ctest --test-dir build --output-on-failure
-1/1 Test #1: stplugin_core_tests ..............   Passed    0.00 sec
-100% tests passed, 0 tests failed out of 1
-
-$ ldd build/obs-adapter/streamer-tools-camera.so | grep obs
-	libobs.so.0 => /lib/x86_64-linux-gnu/libobs.so.0 (...)
-
-$ nm -D build/obs-adapter/streamer-tools-camera.so | grep obs_module
-0000000000001430 T obs_module_free_locale
-0000000000001450 T obs_module_load
-...
-0000000000001490 T obs_module_unload
 ```
 
-This is a genuine, dynamically-linked OBS module -- not the "standalone
+The configure step downloads the pinned `client-sdk-cpp` release (~13 MB) into
-shared library without linking OBS" fallback the scaffolding task's scope
+`build/_deps/livekit-sdk`. Point `-DSTPLUGIN_LIVEKIT_SDK_DIR=<path>` at a
-explicitly allowed as an acceptable compromise. That fallback path is still
+persistent directory to cache it across builds; `-DSTPLUGIN_LIVEKIT_SDK_VERSION`
-exercised (and needed) on macOS/Windows CI for now; see above.
+and `-DSTPLUGIN_LIVEKIT_SDK_TRIPLE` override the pin and the release triple.
+
+The build stages a runnable layout into `build/package/`:
+
+```
+build/package/bin/64bit/streamer-tools-camera.so   (RPATH=$ORIGIN)
+build/package/bin/64bit/liblivekit.so
+build/package/bin/64bit/liblivekit_ffi.so
+build/package/data/locale/en-US.ini
+build/package/licenses/...
+```
+
+That is exactly the layout OBS searches on Linux and Windows —
+`<config>/obs-studio/plugins/<name>/bin/64bit` plus a sibling `data/`, per
+`AddExtraModulePaths()` in obs-studio's `UI/window-basic-main.cpp` — so
+`build/package/` is a straight drop-in. The module resolves the LiveKit
+libraries from `$ORIGIN` (verified: `ldd` on the staged copy resolves both
+to `bin/64bit/`), not from the build tree. macOS is not this shape; see the
+macOS packaging gap under CI.
+
+## Testing this by hand
+
+**Nobody has yet run this in the OBS GUI. That test is still outstanding on
+all three platforms.** To do it on Linux:
+
+```
+mkdir -p ~/.config/obs-studio/plugins/streamer-tools-camera
+cp -r build/package/bin build/package/data \
+      ~/.config/obs-studio/plugins/streamer-tools-camera/
+obs
+```
+
+(That yields `.../streamer-tools-camera/bin/64bit/streamer-tools-camera.so`
+and `.../streamer-tools-camera/data/locale/en-US.ini`, which is what OBS
+looks for.)
+
+Then: Sources → `+` → "streamer-tools Camera" → fill in the server URL, room
+slug and read key from the room's settings page → "Refresh camera list" → pick
+a camera. Check `~/.config/obs-studio/logs/` for
+`[streamer-tools-camera] connected to …` and `[streamer-tools-camera] video
+frame WxH I420`.
+
+What to look for that automated testing could not answer:
+- Does video actually *appear*, right way up, right colours?
+- Is A/V sync acceptable? (see the timestamp caveat above)
+- What is the end-to-end latency versus the existing egress path?
+- Does a publisher restarting mid-show recover cleanly on screen?
+
+### Running the LiveKit integration test
+
+`core/tests/test_integration_livekit` publishes a synthetic camera into a real
+room and subscribes to it through the wrapper. It skips unless
+`STPLUGIN_IT_*` is set:
+
+```
+livekit-server --dev --bind 127.0.0.1 &
+eval "$(python3 scripts/livekit-dev-room.py)"
+ctest --test-dir build -R test_integration_livekit --output-on-failure
+```
+
+## What is verified, and how
+
+Verified on Ubuntu 24.04 (libobs 30.0.2, client-sdk-cpp 1.10.1,
+livekit-server 1.13.6 in dev mode):
+
+| Claim | How it was checked |
+|---|---|
+| The pinned LiveKit SDK links and is callable | `test_livekit_smoke`: `initialize()`/`shutdown()` round-trip, header version asserted equal to the CMake pin |
+| The JSON reader handles real and hostile input | `test_json`, 158 checks, including truncated bodies, HTML error pages, binary garbage, lone surrogates, and a depth-limit case |
+| The API client parses the real response shapes and every error branch | `test_api_client`, 127 checks, against a fake HTTP client **and** a real loopback HTTP server driving the actual platform backend |
+| A dead/stalled/garbage server cannot hang or crash the plugin | loopback cases: truncated JSON, connection closed with no reply, non-HTTP bytes, dead port, stalled server cut off by the client timeout |
+| Session state transitions, track selection, frame geometry | `test_session`, 81 checks, plus real `connect()` failures against the real SDK |
+| **Media actually flows** | `test_integration_livekit` against a real LiveKit server: 36 video frames + 323 audio frames, correct I420 geometry and plane pointers, publisher unpublish → `hasVideo()` false with **no further frames from the dead publisher**, republish → video resumes |
+| **The module loads into real libobs and pushes frames** | a headless libobs harness (`obs_startup` + `obs_reset_audio`/`obs_reset_video` + `obs_open_module`) driving the built module against a stand-in streamer-tools API in front of a real LiveKit server. Log: `connected to ws://…  watching cam-test` then `video frame 640x360 I420`; the camera dropdown populated as `Test Camera` / `Dark Camera (offline)`; status `connected`; clean destroy and unload |
+| A wrong read key is reported, not silently swallowed | same harness with a bad key: status `unknown room slug, or the read key is wrong or has been rotated`, warning info type, retry with backoff, no crash |
+| Changing the selected camera reconnects cleanly | same harness: switch to a dark slot and back. Each switch mints a fresh `obs:<room>:<nonce>` identity and reconnects; video returns; status stays `connected`; no crash, no stale frame |
+| Two sources in one OBS process | same harness with a second source added: both connect with distinct nonce identities, both receive frames, both tear down cleanly |
+
+**Not verified anywhere:**
+- The OBS GUI, on any platform. No human has looked at this in OBS.
+- macOS beyond "CI builds and links the real module and the core tests pass".
+  Its artifact is a bare `.so` with a relative libobs install name and will
+  not load in OBS.app — see the macOS packaging gap under CI.
+- Windows beyond "the core library and the WinHTTP backend compile and their
+  tests pass", from runs predating the current fixes. The WinHTTP backend has
+  never run against a real streamer-tools server, only against the loopback
+  test server in `test_api_client`.
+- A/V sync and end-to-end latency against the existing egress path.
+- Behaviour against the real production streamer-tools server (only against a
+  stand-in serving the same shapes).
+- Token expiry after an hour. Expiry is handled *reactively*: a fatal
+  disconnect makes the worker mint a fresh token and reconnect. The design
+  doc's "proactively refreshed before expiry" is **not** implemented —
+  `client-sdk-cpp` 1.10.1 exposes no way to hand a live `Room` a new token.
 
 ## CI
 
-`.gitea/workflows/build.yml` runs on every push/PR, matrixed across the
+`.gitea/workflows/build.yml` runs on every push, matrixed across the three
-three runners confirmed available to this repo by living under the
+runners available to this repo under the `CyberCoveLLC` org.
-`CyberCoveLLC` org (see the design doc's "CI / build pipeline" section):
 
-| Job | `runs-on` | Runner |
+| Job | `runs-on` | Runner | State |
-|---|---|---|
+|---|---|---|---|
-| `linux` | `ubuntu-latest` | `gitea-runner.internal.cloud-hosting.io` (Global) or `localhost.localdomain` (org-scoped; **note:** now online with `ubuntu-latest`/`ubuntu-24.04`/`ubuntu-22.04` labels -- the design doc recorded it as offline, that's since changed) |
+| `linux` | `ubuntu-24.04` | `localhost.localdomain` | **Green.** Builds the real adapter against Ubuntu's libobs-dev 30.0.2, runs all six test suites, uploads `build/package` as an artifact |
-| `macos` | `macos-latest` | `home-mac` (Global) |
+| `macos` | `macos-latest` | `home-mac` (Global) | **Green.** Builds libobs 30.0.2 from source, then the real adapter; 6/6 tests; artifact uploaded. But see the macOS packaging gap below |
-| `windows` | `windows-latest` | `winvm-builder` (org-scoped to `CyberCoveLLC`) |
+| `windows` | `windows-latest` | `winvm-builder` (org-scoped) | **Failing** — 7/7 completed runs on this branch have failed; see below |
 
-The Linux job installs `libobs-dev` and builds the real OBS adapter module
+The Linux job is pinned to `ubuntu-24.04` rather than `ubuntu-latest`: this
-plus the core library, then runs `ctest`. The macOS/Windows jobs build and
+instance's two Linux runners answer `ubuntu-latest` with different releases,
-test only the core library for now (see toolchain notes above for why).
+and 22.04's `libobs-dev` is OBS 27 — a different API surface, and the LiveKit
+SDK's own `linux-x64` asset does not even link there (hence the
+`ubuntu-22.04` SDK triple; see `cmake/LiveKitSDK.cmake`).
 
-No packaging/release step yet -- out of scope for this pass.
+macOS and Windows use the `obsproject/obs-plugintemplate` buildspec
+bootstrap, trimmed to drop `qt6` (this plugin's properties UI is plain
+`obs_properties_*`), with `obs-studio.version` pinned to 30.0.2 — the same
+version Linux builds against, and deliberately low, because OBS rejects a
+module built against a newer libobs than the one running it.
+
+**Both jobs fall back to a core-library-only build if the bootstrap fails**,
+rather than going red, with a workflow `::warning::` and a "Show what was
+built" step that reports no module. That fallback exists because the
+bootstrap is the least verifiable part of this project — there is no way to
+exercise a macOS or Windows OBS build from the Linux development machine —
+and a permanently red CI teaches people to ignore CI. **Do not remove the
+warning:** a green job that quietly stopped building the plugin is worse than
+a red one.
+
+### Where the macOS bootstrap actually got to
+
+Six CI iterations, each fixing a real failure visible in the logs:
+
+1. Upstream's Xcode generator → `No CMAKE_C_COMPILER could be found` (the
+   runner has the Command Line Tools, not Xcode). Switched to Ninja.
+2. OBS's SDK version regex only matches a full-Xcode SDK path. Synthesised a
+   `MacOSX.platform/Developer/SDKs/MacOSX<ver>.sdk` symlink to the same SDK.
+3. The install walked into `UI/obs-frontend-api`, whose binary is
+   deliberately never built. The install's exit code is now tolerated.
+4. Restricting the install to `libobs/` fixed that but lost the
+   per-configuration export file.
+5. `xattr -r -d com.apple.quarantine` followed the SDK symlink into the
+   read-only system SDK. Symlink moved to the build directory; the xattr step
+   is no longer fatal.
+6. `IMPORTED_LOCATION or IMPORTED_IMPLIB not set for imported target
+   OBS::libobs configuration Release` — OBS 30.0.2 installs
+   `libobsTargets.cmake` without the per-config file that carries the library
+   path. The top-level `CMakeLists.txt` now detects a locationless
+   `OBS::libobs` and points it at the framework the bootstrap just built.
+
+All six are confirmed fixed: the macOS job now downloads obs-deps and
+obs-studio, builds libobs from source, builds and links the real adapter,
+passes 6/6 tests, and uploads its artifact. `otool -L` on the result shows it
+linked against libobs and `@rpath/liblivekit.dylib`.
+
+### macOS packaging gap (known, unfixed)
+
+**The macOS artifact will not load in OBS.app as it stands.** Two reasons,
+neither of which CI can catch, because CI only proves it compiles and links:
+
+1. It is a bare `streamer-tools-camera.so`. OBS on macOS loads plugins as
+   `<name>.plugin` bundles (`Contents/MacOS/<name>`, `Contents/Resources/`,
+   an `Info.plist`), which is what obs-plugintemplate's
+   `cmake/macos/helpers.cmake` builds and which this project deliberately did
+   not vendor.
+2. `otool -L` shows the libobs dependency recorded as the relative path
+   `libobs/libobs.framework/Versions/A/libobs`, inherited from the
+   from-source libobs's own install name. A real plugin needs
+   `@rpath/libobs.framework/Versions/A/libobs` plus an `LC_RPATH` pointing at
+   `OBS.app/Contents/Frameworks`.
+
+Fixing this means either vendoring the template's macOS bundle helpers or
+adding an `install_name_tool` pass and a bundle layout — bounded work, but
+work that has to be done and checked on an actual Mac. It is deliberately not
+attempted here rather than guessed at.
+
+### Where the Windows bootstrap got to
+
+Windows is by far the slowest job — the `lukka/get-cmake` step alone takes
+7-15 minutes on `winvm-builder`, and the runner serialises jobs, so a burst of
+pushes leaves a queue that takes an hour to drain.
+
+**The honest record: every completed Windows CI run on this branch has
+failed. 7 consecutive failures**, at the 7 branch commits (in order) that had
+a completed Windows run as of this writing -- all of them at commits before
+the `-A x64` fix below was applied. As of this writing, a Windows run against
+the commit with that fix is in progress but has not yet completed, and the
+commit with the PowerShell rewrite is still queued behind it (the runner's
+serial queue means fixed commits can sit behind older, unfixed ones for a
+while). Do not read either fix below as "confirmed" until a Windows run
+actually goes green on a commit that includes it; check current CI status
+rather than trusting this paragraph's age.
+
+Two bugs of its own were found and (believed, not yet proven) fixed:
+
+1. Upstream passes `-A x64,version=<Windows SDK>` to the OBS sub-configure,
+   and with a current CMake that `,version=` suffix reappears verbatim in the
+   sub-build's `CMAKE_VS_PLATFORM_NAME` — which obs-studio's own dependency
+   downloader uses as the architecture, sending it after
+   `windows-deps-2023-11-03-x64,version=10.0.26100.0.zip`:
+
+   ```
+   string sub-command JSON member 'hashes windows-x64,version=10.0.26100.0' not found
+   Unable to download .../windows-deps-2023-11-03-x64,version=10.0.26100.0.zip
+   ```
+
+   Plain `-A x64` now.
+2. The Windows CI steps were originally written in bash (via
+   `shell: bash`), which is a poor fit for a `windows-latest` runner's
+   default toolchain expectations; they were rewritten in PowerShell.
+
+Until a Windows run completes green with both fixes in place, Windows should
+be treated as unverified beyond "the core library and the WinHTTP backend
+compile and their tests pass", which earlier (failing-job) runs did show
+before failing later in the job. Expect further iterations there of the same
+kind the macOS bootstrap needed.

buildspec.json

@@ -0,0 +1,54 @@
+{
+    "_comment": [
+        "Dependency manifest for the macOS/Windows OBS SDK bootstrap, in the shape",
+        "obsproject/obs-plugintemplate's cmake/common/buildspec_common.cmake reads.",
+        "Linux does NOT use this: it gets libobs from Ubuntu's libobs-dev package.",
+        "",
+        "obs-studio is pinned to 30.0.2 on purpose, and low rather than high:",
+        "OBS refuses to load a module built against a NEWER libobs than the one",
+        "running (libobs/obs-module.c's version check) and accepts older ones, so",
+        "this pin is the minimum OBS version users need. 30.0.2 is also exactly",
+        "what Ubuntu 24.04's libobs-dev ships, which keeps the three platforms on",
+        "one floor. 30.0.2 supports the modern CMake layout this bootstrap drives",
+        "via -DOBS_CMAKE_VERSION=3.0.0.",
+        "",
+        "prebuilt is obs-deps 2023-11-03, the version obs-studio 30.0.2's own",
+        "buildspec.json pins, with its own published hashes. qt6 is deliberately",
+        "absent: this plugin never links Qt.",
+        "",
+        "The obs-studio hashes are of the GitHub source archives for tag 30.0.2,",
+        "computed on 2026-09-06: .tar.gz (15861643 bytes) for macOS, .zip",
+        "(18168471 bytes) for Windows."
+    ],
+    "dependencies": {
+        "obs-studio": {
+            "version": "30.0.2",
+            "baseUrl": "https://github.com/obsproject/obs-studio/archive/refs/tags",
+            "label": "OBS sources",
+            "hashes": {
+                "macos": "be12c3ad0a85713750d8325e4b1db75086223402d7080d0e3c2833d7c5e83c27",
+                "windows-x64": "970058c49322cfa9cd6d620abb393fed89743ba7e74bd9dbb6ebe0ea8141d9c7"
+            }
+        },
+        "prebuilt": {
+            "version": "2023-11-03",
+            "baseUrl": "https://github.com/obsproject/obs-deps/releases/download",
+            "label": "Pre-Built obs-deps",
+            "hashes": {
+                "macos": "90c2fc069847ec2768dcc867c1c63b112c615ed845a907dc44acab7a97181974",
+                "windows-x64": "d0825a6fb65822c993a3059edfba70d72d2e632ef74893588cf12b1f0d329ce6"
+            }
+        }
+    },
+    "platformConfig": {
+        "macos": {
+            "bundleId": "net.cybercove.streamer-tools-camera"
+        }
+    },
+    "name": "streamer-tools-camera",
+    "displayName": "streamer-tools Camera",
+    "version": "0.1.0",
+    "author": "CyberCoveLLC",
+    "website": "https://repo.anhonesthost.net/CyberCoveLLC/obs-streamer-tools-plugin",
+    "email": "jknapp85@gmail.com"
+}

cmake/LiveKitSDK.cmake

@@ -0,0 +1,221 @@
+# LiveKitSDK.cmake
+#
+# Downloads the prebuilt LiveKit C++ SDK (livekit/client-sdk-cpp) release
+# asset for the host OS/arch, extracts it, and points
+# `find_package(LiveKit CONFIG REQUIRED)` at it.
+#
+# Adapted from livekit-examples/cpp-example-collection's cmake/LiveKitSDK.cmake
+# (fetched 2026-09-06). Deliberate changes from the upstream reference:
+#
+#   1. VERSION must be an exact release number. The upstream helper accepted
+#      VERSION "latest" and resolved it through the GitHub releases API at
+#      configure time. That is exactly what this project must not do: the
+#      design doc calls for a pinned release tag, treating version bumps as
+#      deliberate work (the SDK is young and ships roughly weekly). Dropping
+#      the "latest" path also removes a GitHub-API call -- and its rate
+#      limiting / GITHUB_TOKEN plumbing -- from every CI configure.
+#   2. Exports LIVEKIT_SDK_RUNTIME_LIBS: the shared libraries that must be
+#      staged next to the built OBS plugin module for it to load at runtime
+#      (liblivekit + liblivekit_ffi). Upstream examples run out of the build
+#      tree and never needed this; a redistributable OBS plugin does.
+#   3. Exports LIVEKIT_SDK_INCLUDE_DIR / _LIB_DIR / _BIN_DIR for packaging.
+#
+# Usage:
+#   list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+#   include(LiveKitSDK)
+#   livekit_sdk_setup(VERSION "1.10.1" SDK_DIR "${CMAKE_BINARY_DIR}/_deps/livekit-sdk")
+#   find_package(LiveKit CONFIG REQUIRED)
+
+include_guard(GLOBAL)
+
+# -------------------- Host detection --------------------
+function(_lk_detect_host out_os out_arch)
+  if(WIN32)
+    set(_os "windows")
+  elseif(APPLE)
+    set(_os "macos")
+  elseif(UNIX)
+    set(_os "linux")
+  else()
+    message(FATAL_ERROR "LiveKitSDK: unsupported host OS")
+  endif()
+
+  # Prefer the *target* processor when cross-compiling is expressed through
+  # CMAKE_OSX_ARCHITECTURES (macOS CI runners are arm64 but may target x64).
+  set(_proc "${CMAKE_HOST_SYSTEM_PROCESSOR}")
+  if(APPLE AND CMAKE_OSX_ARCHITECTURES)
+    list(LENGTH CMAKE_OSX_ARCHITECTURES _n_arch)
+    if(_n_arch GREATER 1)
+      message(FATAL_ERROR
+        "LiveKitSDK: CMAKE_OSX_ARCHITECTURES lists ${_n_arch} architectures "
+        "(${CMAKE_OSX_ARCHITECTURES}). client-sdk-cpp ships single-arch "
+        "dylibs only, so universal binaries are not supported. Build one "
+        "architecture at a time.")
+    endif()
+    list(GET CMAKE_OSX_ARCHITECTURES 0 _proc)
+  endif()
+
+  string(TOLOWER "${_proc}" _proc_l)
+  if(_proc_l MATCHES "^(x86_64|amd64)$")
+    set(_arch "x64")
+  elseif(_proc_l MATCHES "^(arm64|aarch64)$")
+    set(_arch "arm64")
+  else()
+    message(FATAL_ERROR "LiveKitSDK: unsupported host arch: ${_proc}")
+  endif()
+
+  set(${out_os}   "${_os}"   PARENT_SCOPE)
+  set(${out_arch} "${_arch}" PARENT_SCOPE)
+endfunction()
+
+function(_lk_default_triple out_triple)
+  _lk_detect_host(_os _arch)
+  if(_os STREQUAL "linux")
+    # NOT the generic "linux-<arch>" asset, despite the name. That one is
+    # built on Ubuntu 24.04 and needs GLIBC_2.38 and GLIBCXX_3.4.32: linking
+    # it on Ubuntu 22.04 fails outright ("undefined reference to
+    # std::ios_base_library_init()@GLIBCXX_3.4.32", "__isoc23_strtol@GLIBC_2.38"),
+    # which is exactly what happened when CI landed on a 22.04 runner.
+    # The ubuntu-22.04 asset needs at most GLIBC_2.35 / GLIBCXX_3.4.30, so it
+    # links and runs on 22.04 AND on everything newer -- the right floor for a
+    # plugin that gets handed to directors as a binary.
+    set(${out_triple} "ubuntu-22.04-${_arch}" PARENT_SCOPE)
+  else()
+    set(${out_triple} "${_os}-${_arch}" PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(_lk_archive_ext out_ext)
+  if(WIN32)
+    set(${out_ext} "zip" PARENT_SCOPE)
+  else()
+    set(${out_ext} "tar.gz" PARENT_SCOPE)
+  endif()
+endfunction()
+
+# -------------------- Public entrypoint --------------------
+# livekit_sdk_setup(
+#   VERSION <x.y.z>                   REQUIRED, exact -- "latest" is rejected
+#   SDK_DIR <dir>                     REQUIRED, where the archive is extracted
+#   [REPO <org/repo>]                 default: livekit/client-sdk-cpp
+#   [SHA256 <hash>]                   optional: verify the downloaded archive
+#   [TRIPLE <os-arch>]                optional override (e.g. ubuntu-24.04-x64)
+#   [DOWNLOAD_DIR <dir>]              default: <build>/_downloads
+#   [NO_DOWNLOAD]                     fail instead of downloading if absent
+# )
+function(livekit_sdk_setup)
+  set(options NO_DOWNLOAD)
+  set(oneValueArgs VERSION SDK_DIR REPO SHA256 TRIPLE DOWNLOAD_DIR)
+  cmake_parse_arguments(LK "${options}" "${oneValueArgs}" "" ${ARGN})
+
+  if(NOT LK_VERSION)
+    message(FATAL_ERROR "livekit_sdk_setup: VERSION is required")
+  endif()
+  if(LK_VERSION STREQUAL "latest")
+    message(FATAL_ERROR
+      "livekit_sdk_setup: VERSION=\"latest\" is deliberately not supported. "
+      "This project pins an exact client-sdk-cpp release; see the comment at "
+      "the top of cmake/LiveKitSDK.cmake.")
+  endif()
+  if(NOT LK_VERSION MATCHES "^[0-9]+\\.[0-9]+\\.[0-9]+$")
+    message(FATAL_ERROR "livekit_sdk_setup: VERSION must be x.y.z, got '${LK_VERSION}'")
+  endif()
+  if(NOT LK_SDK_DIR)
+    message(FATAL_ERROR "livekit_sdk_setup: SDK_DIR is required")
+  endif()
+
+  if(NOT LK_REPO)
+    set(LK_REPO "livekit/client-sdk-cpp")
+  endif()
+  if(NOT LK_DOWNLOAD_DIR)
+    set(LK_DOWNLOAD_DIR "${CMAKE_BINARY_DIR}/_downloads")
+  endif()
+  if(NOT LK_TRIPLE)
+    _lk_default_triple(LK_TRIPLE)
+  endif()
+
+  _lk_archive_ext(_ext)
+  set(_archive "livekit-sdk-${LK_TRIPLE}-${LK_VERSION}.${_ext}")
+  set(_url "https://github.com/${LK_REPO}/releases/download/v${LK_VERSION}/${_archive}")
+  set(_archive_path "${LK_DOWNLOAD_DIR}/${_archive}")
+
+  # The archive contains a single top-level folder named after the asset.
+  set(_extracted_root "${LK_SDK_DIR}/livekit-sdk-${LK_TRIPLE}-${LK_VERSION}")
+
+  file(MAKE_DIRECTORY "${LK_DOWNLOAD_DIR}")
+  file(MAKE_DIRECTORY "${LK_SDK_DIR}")
+
+  if(NOT EXISTS "${_extracted_root}/lib/cmake")
+    if(LK_NO_DOWNLOAD)
+      message(FATAL_ERROR
+        "LiveKitSDK: SDK not found at:\n  ${_extracted_root}\nand NO_DOWNLOAD was set.")
+    endif()
+
+    message(STATUS "LiveKitSDK: downloading ${_url}")
+
+    if(LK_SHA256)
+      file(DOWNLOAD "${_url}" "${_archive_path}"
+        SHOW_PROGRESS TLS_VERIFY ON
+        EXPECTED_HASH "SHA256=${LK_SHA256}"
+        STATUS _st LOG _log)
+    else()
+      file(DOWNLOAD "${_url}" "${_archive_path}"
+        SHOW_PROGRESS TLS_VERIFY ON
+        STATUS _st LOG _log)
+    endif()
+
+    list(GET _st 0 _code)
+    list(GET _st 1 _msg)
+    if(NOT _code EQUAL 0)
+      file(REMOVE "${_archive_path}")
+      message(STATUS "LiveKitSDK: download log:\n${_log}")
+      message(FATAL_ERROR
+        "LiveKitSDK: download failed\nURL: ${_url}\nStatus: ${_code}\nMessage: ${_msg}\n"
+        "If this triple has no release asset, pass TRIPLE explicitly.")
+    endif()
+
+    # Remove any previous partial extraction.
+    file(REMOVE_RECURSE "${_extracted_root}")
+
+    message(STATUS "LiveKitSDK: extracting ${_archive_path}")
+    file(ARCHIVE_EXTRACT INPUT "${_archive_path}" DESTINATION "${LK_SDK_DIR}")
+  endif()
+
+  if(NOT EXISTS "${_extracted_root}/lib/cmake/LiveKit/LiveKitConfig.cmake")
+    message(FATAL_ERROR
+      "LiveKitSDK: extracted SDK does not look valid (missing "
+      "lib/cmake/LiveKit/LiveKitConfig.cmake)\nExpected under: ${_extracted_root}")
+  endif()
+
+  # Make find_package(LiveKit CONFIG REQUIRED) work in the caller's scope.
+  list(PREPEND CMAKE_PREFIX_PATH "${_extracted_root}")
+  set(CMAKE_PREFIX_PATH "${CMAKE_PREFIX_PATH}" PARENT_SCOPE)
+  set(LiveKit_DIR "${_extracted_root}/lib/cmake/LiveKit" PARENT_SCOPE)
+
+  # --- Runtime libraries, for staging next to the plugin module ------------
+  # Windows keeps the DLLs in bin/ and the import libs in lib/; the Unix
+  # platforms put the shared objects directly in lib/.
+  if(WIN32)
+    file(GLOB _runtime_libs "${_extracted_root}/bin/*.dll")
+  elseif(APPLE)
+    file(GLOB _runtime_libs "${_extracted_root}/lib/*.dylib")
+  else()
+    file(GLOB _runtime_libs "${_extracted_root}/lib/*.so" "${_extracted_root}/lib/*.so.*")
+  endif()
+  if(NOT _runtime_libs)
+    message(FATAL_ERROR
+      "LiveKitSDK: found no runtime shared libraries under ${_extracted_root}. "
+      "The release layout may have changed for version ${LK_VERSION}.")
+  endif()
+
+  set(LIVEKIT_SDK_EXTRACTED_ROOT "${_extracted_root}" CACHE PATH "LiveKit SDK extracted root" FORCE)
+  set(LIVEKIT_SDK_INCLUDE_DIR "${_extracted_root}/include" CACHE PATH "LiveKit SDK include dir" FORCE)
+  set(LIVEKIT_SDK_LIB_DIR "${_extracted_root}/lib" CACHE PATH "LiveKit SDK lib dir" FORCE)
+  set(LIVEKIT_SDK_BIN_DIR "${_extracted_root}/bin" CACHE PATH "LiveKit SDK bin dir" FORCE)
+  set(LIVEKIT_SDK_RUNTIME_LIBS "${_runtime_libs}" CACHE STRING "LiveKit SDK runtime shared libraries" FORCE)
+  set(LIVEKIT_SDK_URL_USED "${_url}" CACHE STRING "LiveKit SDK URL used" FORCE)
+  set(LIVEKIT_SDK_VERSION_RESOLVED "${LK_VERSION}" CACHE STRING "LiveKit SDK version" FORCE)
+  set(LIVEKIT_SDK_TRIPLE_USED "${LK_TRIPLE}" CACHE STRING "LiveKit SDK triple" FORCE)
+
+  message(STATUS "LiveKitSDK: using SDK ${LK_VERSION} (${LK_TRIPLE}) at ${_extracted_root}")
+endfunction()

cmake/common/buildspec_common.cmake

@@ -0,0 +1,370 @@
+# Adapted from obsproject/obs-plugintemplate (cmake/common/buildspec_common.cmake,
+# master as of 2026-09-06). Deliberate changes from upstream, all recorded here
+# so a future re-sync knows what to keep:
+#
+#   1. _setup_obs_studio builds and installs the `libobs` target, not
+#      `obs-frontend-api`. This plugin's properties UI is plain
+#      obs_properties_* and it never touches the frontend API, so building it
+#      would only drag Qt back in -- which is the whole point of dropping qt6
+#      from dependencies_list.
+#   2. It passes -DENABLE_UI:BOOL=OFF and -DENABLE_SCRIPTING:BOOL=OFF as well
+#      as upstream's -DENABLE_FRONTEND:BOOL=OFF. The pinned OBS (30.0.2)
+#      predates the ENABLE_FRONTEND option and gates its Qt-dependent UI on
+#      ENABLE_UI instead; without this the sub-build configures the whole
+#      OBS UI and demands Qt.
+#   3. Only the Release configuration is built and installed. Upstream builds
+#      Debug as well; nothing here consumes a debug libobs, and it doubles the
+#      slowest step in CI.
+#   4. macOS uses the Ninja generator and a single architecture, not upstream's
+#      Xcode generator and forced universal build. See the comment at that
+#      branch: a runner with only the Command Line Tools has no xcodebuild.
+#   5. Generator flags are built as CMake lists so each becomes its own argv
+#      entry, rather than upstream's space-separated strings passed unquoted.
+#   6. The install step targets the libobs subdirectory rather than the whole
+#      build tree, so it does not trip over the install rules of targets that
+#      were deliberately never built.
+#   7. _resolve_versioned_macos_sdk exists at all -- see its own comment.
+#
+
+include_guard(GLOBAL)
+
+# _check_deps_version: Checks for obs-deps VERSION file in prefix paths
+function(_check_deps_version version)
+  set(found FALSE)
+
+  foreach(path IN LISTS CMAKE_PREFIX_PATH)
+    if(EXISTS "${path}/share/obs-deps/VERSION")
+      if(dependency STREQUAL qt6 AND NOT EXISTS "${path}/lib/cmake/Qt6/Qt6Config.cmake")
+        set(found FALSE)
+        continue()
+      endif()
+
+      file(READ "${path}/share/obs-deps/VERSION" _check_version)
+      string(REPLACE "\n" "" _check_version "${_check_version}")
+      string(REPLACE "-" "." _check_version "${_check_version}")
+      string(REPLACE "-" "." version "${version}")
+
+      if(_check_version VERSION_EQUAL version)
+        set(found TRUE)
+        break()
+      elseif(_check_version VERSION_LESS version)
+        message(
+          AUTHOR_WARNING
+          "Older ${label} version detected in ${path}: \n"
+          "Found ${_check_version}, require ${version}"
+        )
+        list(REMOVE_ITEM CMAKE_PREFIX_PATH "${path}")
+        list(APPEND CMAKE_PREFIX_PATH "${path}")
+        set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH})
+        continue()
+      else()
+        message(
+          AUTHOR_WARNING
+          "Newer ${label} version detected in ${path}: \n"
+          "Found ${_check_version}, require ${version}"
+        )
+        set(found TRUE)
+        break()
+      endif()
+    endif()
+  endforeach()
+
+  return(PROPAGATE found CMAKE_PREFIX_PATH)
+endfunction()
+
+# _resolve_versioned_macos_sdk: return an SDK path that satisfies OBS's own
+# macOS SDK version check.
+#
+# Not upstream. OBS 30.0.2's cmake/macos/compilerconfig.cmake reads the SDK
+# version straight out of CMAKE_OSX_SYSROOT with this regex:
+#
+#   ".+/MacOSX.platform/Developer/SDKs/MacOSX([0-9]+\\.[0-9])+\\.sdk$"
+#
+# and hard-fails if it does not match ("Your macOS SDK version () is too low",
+# with an empty version, which is the tell). That pattern only ever matches a
+# full-Xcode SDK path; a Command-Line-Tools-only install has its SDK at
+# /Library/Developer/CommandLineTools/SDKs/MacOSX<ver>.sdk, with no
+# MacOSX.platform/Developer/SDKs segment at all, and can never match.
+#
+# Upstream never hits this because it uses the Xcode generator, where
+# CMAKE_OSX_SYSROOT stays the literal string "macosx" and Xcode resolves it
+# late. This project uses Ninja (the CI runner has no xcodebuild), so CMake
+# resolves the sysroot eagerly and the regex runs against a real path.
+#
+# So: if the toolchain's own SDK path already matches, use it untouched.
+# Otherwise build a symlink tree under the build directory whose shape matches
+# the regex and which points at exactly the same SDK. Nothing about the
+# compilation changes -- only the spelling of the path, which is all the check
+# reads.
+function(_resolve_versioned_macos_sdk out_path)
+  set(${out_path} "" PARENT_SCOPE)
+
+  execute_process(
+    COMMAND xcrun --show-sdk-path
+    OUTPUT_VARIABLE _sdk
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    RESULT_VARIABLE _rc
+    ERROR_QUIET
+  )
+  if(NOT _rc EQUAL 0 OR NOT _sdk)
+    message(WARNING "Could not determine the macOS SDK path via xcrun; leaving CMAKE_OSX_SYSROOT alone.")
+    return()
+  endif()
+
+  if(_sdk MATCHES "/MacOSX\\.platform/Developer/SDKs/MacOSX[0-9]+\\.[0-9]+\\.sdk$")
+    set(${out_path} "${_sdk}" PARENT_SCOPE)
+    return()
+  endif()
+
+  execute_process(
+    COMMAND xcrun --show-sdk-version
+    OUTPUT_VARIABLE _sdk_version
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    RESULT_VARIABLE _rc
+    ERROR_QUIET
+  )
+  if(NOT _rc EQUAL 0 OR NOT _sdk_version MATCHES "^([0-9]+)\\.([0-9]+)")
+    message(WARNING "Could not determine the macOS SDK version via xcrun (got '${_sdk_version}').")
+    return()
+  endif()
+  set(_short "${CMAKE_MATCH_1}.${CMAKE_MATCH_2}")
+
+  # Deliberately under the BUILD directory, not .deps/: cmake/macos/
+  # buildspec.cmake runs `xattr -r -d com.apple.quarantine` over the whole
+  # dependency directory, which would follow this symlink into the read-only
+  # system SDK and fail with "Permission denied".
+  set(_link_dir "${CMAKE_BINARY_DIR}/macos-sdk/MacOSX.platform/Developer/SDKs")
+  set(_link "${_link_dir}/MacOSX${_short}.sdk")
+  file(MAKE_DIRECTORY "${_link_dir}")
+  if(NOT EXISTS "${_link}")
+    file(CREATE_LINK "${_sdk}" "${_link}" SYMBOLIC)
+  endif()
+  if(EXISTS "${_link}")
+    message(STATUS "macOS SDK ${_short} at ${_sdk}; presenting it to OBS as ${_link}")
+    set(${out_path} "${_link}" PARENT_SCOPE)
+  else()
+    message(WARNING "Could not create the versioned macOS SDK symlink at ${_link}.")
+  endif()
+endfunction()
+
+# _setup_obs_studio: Create obs-studio build project, then build libobs and obs-frontend-api
+function(_setup_obs_studio)
+  if(NOT libobs_DIR)
+    set(_is_fresh --fresh)
+  endif()
+
+  # Every generator-specific flag is built as a proper CMake list, so each
+  # element becomes its own argv entry. Upstream packs several flags into one
+  # space-separated string and passes it unquoted, which execute_process hands
+  # to cmake as a single argument -- it happens not to matter there because
+  # those flags are optional, but -DCMAKE_BUILD_TYPE is not.
+  set(_cmake_arch "")
+  set(_cmake_extra "")
+
+  if(OS_WINDOWS)
+    set(_cmake_generator "${CMAKE_GENERATOR}")
+    # Plain "-A x64", NOT upstream's "-A x64,version=<Windows SDK>". With a
+    # current CMake the ",version=" suffix comes back out verbatim in the
+    # sub-build's CMAKE_VS_PLATFORM_NAME, and obs-studio's OWN dependency
+    # downloader keys its release assets off that value -- so the sub-configure
+    # goes looking for a file that cannot exist:
+    #
+    #   string sub-command JSON member 'hashes windows-x64,version=10.0.26100.0'
+    #     not found
+    #   Unable to download .../windows-deps-2023-11-03-x64,version=10.0.26100.0.zip
+    #
+    # The Windows SDK is selected automatically anyway ("Selecting Windows SDK
+    # version 10.0.26100.0"), and CMAKE_SYSTEM_VERSION is passed below.
+    list(APPEND _cmake_arch -A "${arch}")
+    list(APPEND _cmake_extra "-DCMAKE_SYSTEM_VERSION=${CMAKE_SYSTEM_VERSION}")
+  elseif(OS_MACOS)
+    # Ninja, not upstream's Xcode generator. A runner with only the Command
+    # Line Tools installed has no xcodebuild, and the Xcode generator then
+    # fails the OBS sub-configure outright with "No CMAKE_C_COMPILER could be
+    # found" -- observed on the `home-mac` CI runner. Ninja is single-config,
+    # hence the explicit CMAKE_BUILD_TYPE below.
+    set(_cmake_generator "Ninja")
+    # Single-architecture, not upstream's forced universal build: this plugin
+    # is built for one architecture anyway (client-sdk-cpp ships single-arch
+    # dylibs), so building libobs universal would double the slowest step in
+    # CI for a slice nothing links against.
+    if(CMAKE_OSX_ARCHITECTURES)
+      list(APPEND _cmake_arch "-DCMAKE_OSX_ARCHITECTURES:STRING=${CMAKE_OSX_ARCHITECTURES}")
+    endif()
+    list(APPEND _cmake_extra "-DCMAKE_BUILD_TYPE=Release")
+    if(CMAKE_OSX_DEPLOYMENT_TARGET)
+      list(APPEND _cmake_extra "-DCMAKE_OSX_DEPLOYMENT_TARGET=${CMAKE_OSX_DEPLOYMENT_TARGET}")
+    endif()
+    _resolve_versioned_macos_sdk(_sdk_path)
+    if(_sdk_path)
+      list(APPEND _cmake_extra "-DCMAKE_OSX_SYSROOT=${_sdk_path}")
+    endif()
+  endif()
+
+  message(STATUS "Configure ${label} (${arch})")
+  execute_process(
+    COMMAND
+      "${CMAKE_COMMAND}" -S "${dependencies_dir}/${_obs_destination}" -B
+      "${dependencies_dir}/${_obs_destination}/build_${arch}" -G ${_cmake_generator} ${_cmake_arch}
+      -DOBS_CMAKE_VERSION:STRING=3.0.0 -DENABLE_PLUGINS:BOOL=OFF -DENABLE_FRONTEND:BOOL=OFF
+      -DENABLE_UI:BOOL=OFF -DENABLE_SCRIPTING:BOOL=OFF -DENABLE_BROWSER:BOOL=OFF
+      -DOBS_VERSION_OVERRIDE:STRING=${_obs_version} "-DCMAKE_PREFIX_PATH=${CMAKE_PREFIX_PATH}" ${_is_fresh}
+      ${_cmake_extra}
+    RESULT_VARIABLE _process_result
+    COMMAND_ERROR_IS_FATAL ANY
+  )
+  message(STATUS "Configure ${label} (${arch}) - done")
+
+  message(STATUS "Build ${label} (Release - ${arch})")
+  execute_process(
+    COMMAND "${CMAKE_COMMAND}" --build build_${arch} --target libobs --config Release --parallel
+    WORKING_DIRECTORY "${dependencies_dir}/${_obs_destination}"
+    RESULT_VARIABLE _process_result
+    COMMAND_ERROR_IS_FATAL ANY
+  )
+  message(STATUS "Build ${label} (Release - ${arch}) - done")
+
+  # Install the whole build tree, and tolerate a non-zero exit.
+  #
+  # Installing from the top-level build directory walks every subproject's
+  # cmake_install.cmake, including UI/obs-frontend-api's, which fails on a
+  # binary this build deliberately never produced (that is the whole point of
+  # dropping Qt):
+  #
+  #   file INSTALL cannot find ".../obs-frontend-api.dylib": No such file
+  #
+  # Restricting --install to the libobs subdirectory avoids that error, but
+  # then the per-configuration export file (libobsTargets-release.cmake) never
+  # lands, and every consumer fails with "IMPORTED_LOCATION or IMPORTED_IMPLIB
+  # not set for imported target OBS::libobs configuration Release". So run the
+  # full install exactly as upstream does, let it get through libobs, and
+  # ignore the error it hits afterwards. If libobs really did not install, the
+  # find_package(libobs) in the top-level CMakeLists is where that surfaces --
+  # loudly, and with a far more useful message than a half-installed tree.
+  message(STATUS "Install ${label} (${arch})")
+  execute_process(
+    COMMAND
+      "${CMAKE_COMMAND}" --install build_${arch} --component Development --config Release --prefix "${dependencies_dir}"
+    WORKING_DIRECTORY "${dependencies_dir}/${_obs_destination}"
+    RESULT_VARIABLE _install_result
+    OUTPUT_QUIET
+  )
+  if(NOT _install_result EQUAL 0)
+    message(
+      STATUS
+      "Install ${label} (${arch}) reported errors; expected, because install rules exist for "
+      "targets this build skips. Continuing -- find_package(libobs) is the real check."
+    )
+  endif()
+  message(STATUS "Install ${label} (${arch}) - done")
+endfunction()
+
+# _check_dependencies: Fetch and extract pre-built OBS build dependencies
+function(_check_dependencies)
+  file(READ "${CMAKE_CURRENT_SOURCE_DIR}/buildspec.json" buildspec)
+
+  string(JSON dependency_data GET ${buildspec} dependencies)
+
+  foreach(dependency IN LISTS dependencies_list)
+    string(JSON data GET ${dependency_data} ${dependency})
+    string(JSON version GET ${data} version)
+    string(JSON hash GET ${data} hashes ${platform})
+    string(JSON url GET ${data} baseUrl)
+    string(JSON label GET ${data} label)
+    string(JSON revision ERROR_VARIABLE error GET ${data} revision ${platform})
+
+    message(STATUS "Setting up ${label} (${arch})")
+
+    set(file "${${dependency}_filename}")
+    set(destination "${${dependency}_destination}")
+    string(REPLACE "VERSION" "${version}" file "${file}")
+    string(REPLACE "VERSION" "${version}" destination "${destination}")
+    string(REPLACE "ARCH" "${arch}" file "${file}")
+    string(REPLACE "ARCH" "${arch}" destination "${destination}")
+    if(revision)
+      string(REPLACE "_REVISION" "_v${revision}" file "${file}")
+      string(REPLACE "-REVISION" "-v${revision}" file "${file}")
+    else()
+      string(REPLACE "_REVISION" "" file "${file}")
+      string(REPLACE "-REVISION" "" file "${file}")
+    endif()
+
+    if(EXISTS "${dependencies_dir}/.dependency_${dependency}_${arch}.sha256")
+      file(
+        READ
+        "${dependencies_dir}/.dependency_${dependency}_${arch}.sha256"
+        OBS_DEPENDENCY_${dependency}_${arch}_HASH
+      )
+    endif()
+
+    set(skip FALSE)
+    if(dependency STREQUAL prebuilt OR dependency STREQUAL qt6)
+      if(OBS_DEPENDENCY_${dependency}_${arch}_HASH STREQUAL ${hash})
+        _check_deps_version(${version})
+
+        if(found)
+          set(skip TRUE)
+        endif()
+      endif()
+    endif()
+
+    if(skip)
+      message(STATUS "Setting up ${label} (${arch}) - skipped")
+      continue()
+    endif()
+
+    if(dependency STREQUAL obs-studio)
+      set(url ${url}/${file})
+    else()
+      set(url ${url}/${version}/${file})
+    endif()
+
+    if(NOT EXISTS "${dependencies_dir}/${file}")
+      message(STATUS "Downloading ${url}")
+      file(DOWNLOAD "${url}" "${dependencies_dir}/${file}" STATUS download_status EXPECTED_HASH SHA256=${hash})
+
+      list(GET download_status 0 error_code)
+      list(GET download_status 1 error_message)
+      if(error_code GREATER 0)
+        message(STATUS "Downloading ${url} - Failure")
+        message(FATAL_ERROR "Unable to download ${url}, failed with error: ${error_message}")
+        file(REMOVE "${dependencies_dir}/${file}")
+      else()
+        message(STATUS "Downloading ${url} - done")
+      endif()
+    endif()
+
+    if(NOT OBS_DEPENDENCY_${dependency}_${arch}_HASH STREQUAL ${hash})
+      file(REMOVE_RECURSE "${dependencies_dir}/${destination}")
+    endif()
+
+    if(NOT EXISTS "${dependencies_dir}/${destination}")
+      file(MAKE_DIRECTORY "${dependencies_dir}/${destination}")
+      if(dependency STREQUAL obs-studio)
+        file(ARCHIVE_EXTRACT INPUT "${dependencies_dir}/${file}" DESTINATION "${dependencies_dir}")
+      else()
+        file(ARCHIVE_EXTRACT INPUT "${dependencies_dir}/${file}" DESTINATION "${dependencies_dir}/${destination}")
+      endif()
+    endif()
+
+    file(WRITE "${dependencies_dir}/.dependency_${dependency}_${arch}.sha256" "${hash}")
+
+    if(dependency STREQUAL prebuilt)
+      list(APPEND CMAKE_PREFIX_PATH "${dependencies_dir}/${destination}")
+    elseif(dependency STREQUAL qt6)
+      list(APPEND CMAKE_PREFIX_PATH "${dependencies_dir}/${destination}")
+    elseif(dependency STREQUAL obs-studio)
+      set(_obs_version ${version})
+      set(_obs_destination "${destination}")
+      list(APPEND CMAKE_PREFIX_PATH "${dependencies_dir}")
+    endif()
+
+    message(STATUS "Setting up ${label} (${arch}) - done")
+  endforeach()
+
+  list(REMOVE_DUPLICATES CMAKE_PREFIX_PATH)
+
+  set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} CACHE PATH "CMake prefix search path" FORCE)
+
+  _setup_obs_studio()
+endfunction()

cmake/common/osconfig.cmake

@@ -0,0 +1,20 @@
+# CMake operating system bootstrap module
+
+include_guard(GLOBAL)
+
+if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
+  set(CMAKE_C_EXTENSIONS FALSE)
+  set(CMAKE_CXX_EXTENSIONS FALSE)
+  list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/windows")
+  set(OS_WINDOWS TRUE)
+elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin")
+  set(CMAKE_C_EXTENSIONS FALSE)
+  set(CMAKE_CXX_EXTENSIONS FALSE)
+  list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/macos")
+  set(OS_MACOS TRUE)
+elseif(CMAKE_HOST_SYSTEM_NAME MATCHES "Linux|FreeBSD|OpenBSD")
+  set(CMAKE_CXX_EXTENSIONS FALSE)
+  list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/linux")
+  string(TOUPPER "${CMAKE_HOST_SYSTEM_NAME}" _SYSTEM_NAME_U)
+  set(OS_${_SYSTEM_NAME_U} TRUE)
+endif()

cmake/macos/buildspec.cmake

@@ -0,0 +1,46 @@
+# CMake macOS build dependencies module
+#
+# Adapted from obsproject/obs-plugintemplate. Only change from upstream: qt6
+# is dropped from dependencies_list. This plugin's properties UI is plain
+# obs_properties_*, it never links Qt, and the OBS sub-build is configured
+# with ENABLE_UI=OFF -- so downloading a ~100 MB Qt bundle on every CI run
+# would buy nothing.
+
+include_guard(GLOBAL)
+
+include(buildspec_common)
+
+# _check_dependencies_macos: Set up macOS slice for _check_dependencies
+function(_check_dependencies_macos)
+  set(arch universal)
+  set(platform macos)
+
+  file(READ "${CMAKE_CURRENT_SOURCE_DIR}/buildspec.json" buildspec)
+
+  set(dependencies_dir "${CMAKE_CURRENT_SOURCE_DIR}/.deps")
+  set(prebuilt_filename "macos-deps-VERSION-ARCH_REVISION.tar.xz")
+  set(prebuilt_destination "obs-deps-VERSION-ARCH")
+  set(obs-studio_filename "VERSION.tar.gz")
+  set(obs-studio_destination "obs-studio-VERSION")
+  set(dependencies_list prebuilt obs-studio)
+
+  _check_dependencies()
+
+  # Clearing the quarantine flag on the downloaded dependencies is a
+  # convenience, not a correctness requirement, so a failure here must not
+  # take the whole configure down with it. Upstream makes it fatal.
+  execute_process(
+    COMMAND "xattr" -r -d com.apple.quarantine "${dependencies_dir}"
+    RESULT_VARIABLE result
+    OUTPUT_QUIET
+    ERROR_QUIET
+  )
+  if(NOT result EQUAL 0)
+    message(STATUS "Could not clear the quarantine attribute under ${dependencies_dir} (continuing)")
+  endif()
+
+  list(APPEND CMAKE_FRAMEWORK_PATH "${dependencies_dir}/Frameworks")
+  set(CMAKE_FRAMEWORK_PATH ${CMAKE_FRAMEWORK_PATH} PARENT_SCOPE)
+endfunction()
+
+_check_dependencies_macos()

cmake/windows/buildspec.cmake

@@ -0,0 +1,28 @@
+# CMake Windows build dependencies module
+#
+# Adapted from obsproject/obs-plugintemplate. Only change from upstream: qt6
+# is dropped from dependencies_list. This plugin's properties UI is plain
+# obs_properties_*, it never links Qt, and the OBS sub-build is configured
+# with ENABLE_UI=OFF -- so downloading a ~100 MB Qt bundle on every CI run
+# would buy nothing.
+
+include_guard(GLOBAL)
+
+include(buildspec_common)
+
+# _check_dependencies_windows: Set up Windows slice for _check_dependencies
+function(_check_dependencies_windows)
+  set(arch ${CMAKE_VS_PLATFORM_NAME})
+  set(platform windows-${arch})
+
+  set(dependencies_dir "${CMAKE_CURRENT_SOURCE_DIR}/.deps")
+  set(prebuilt_filename "windows-deps-VERSION-ARCH-REVISION.zip")
+  set(prebuilt_destination "obs-deps-VERSION-ARCH")
+  set(obs-studio_filename "VERSION.zip")
+  set(obs-studio_destination "obs-studio-VERSION")
+  set(dependencies_list prebuilt obs-studio)
+
+  _check_dependencies()
+endfunction()
+
+_check_dependencies_windows()

core/CMakeLists.txt

@@ -4,15 +4,50 @@
 # 2026-09-06-obs-camera-plugin-design.md in the streamer-tools repo) --
 # this must build and test headlessly on every platform.
 
-add_library(stplugin_core STATIC
+set(STPLUGIN_CORE_SOURCES
     src/core.cpp
+    src/json.cpp
+    src/http_common.cpp
+    src/api_client.cpp
+    src/session_types.cpp
+    src/session.cpp
 )
 
+# HTTP backend, one per platform. See core/include/stplugin/http.h for why
+# this is split rather than using libcurl everywhere.
+if(WIN32)
+    list(APPEND STPLUGIN_CORE_SOURCES src/http_winhttp.cpp)
+else()
+    list(APPEND STPLUGIN_CORE_SOURCES src/http_curl.cpp)
+endif()
+
+add_library(stplugin_core STATIC ${STPLUGIN_CORE_SOURCES})
+
 target_include_directories(stplugin_core
     PUBLIC
         ${CMAKE_CURRENT_SOURCE_DIR}/include
 )
 
+target_link_libraries(stplugin_core
+    PUBLIC
+        LiveKit::livekit
+)
+
+if(WIN32)
+    target_link_libraries(stplugin_core PRIVATE winhttp)
+else()
+    find_package(CURL REQUIRED)
+    target_link_libraries(stplugin_core PRIVATE CURL::libcurl)
+endif()
+
+find_package(Threads REQUIRED)
+target_link_libraries(stplugin_core PUBLIC Threads::Threads)
+
+target_compile_definitions(stplugin_core PRIVATE
+    STPLUGIN_CORE_VERSION="${PROJECT_VERSION}"
+    STPLUGIN_LIVEKIT_SDK_VERSION="${LIVEKIT_SDK_VERSION_RESOLVED}"
+)
+
 set_target_properties(stplugin_core PROPERTIES
     POSITION_INDEPENDENT_CODE ON
 )

core/include/stplugin/api_client.h

@@ -0,0 +1,133 @@
+/*
+streamer-tools OBS Camera Plugin - streamer-tools API client
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#pragma once
+
+// Client for the two read-key-scoped endpoints in
+// apps/server/src/obs/plugin.routes.ts (streamer-tools repo):
+//
+//   GET  /api/obs/:slug/slots?key=<readKey>
+//        200 { slots: [ { identity, displayName, live } ] }
+//        404 { error: 'not found' }            wrong key OR unknown room
+//        503 { error: 'livekit not configured' }
+//
+//   POST /api/obs/:slug/token?key=<readKey>
+//        200 { lkToken, wsUrl, identity }
+//        404 / 503 as above
+//
+// The server deliberately answers a wrong key and an unknown slug identically
+// (404), so this client must not claim to know which it was.
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "stplugin/core.h"
+#include "stplugin/http.h"
+
+namespace stplugin {
+
+enum class ApiStatus {
+    Ok,
+    /// server URL / slug / key were not all filled in
+    InvalidConfig,
+    /// request never completed (DNS, TLS, timeout, ...)
+    NetworkError,
+    /// HTTP 404: unknown room slug or wrong read key -- indistinguishable
+    NotFound,
+    /// HTTP 503: the server has no LiveKit credentials configured
+    Unavailable,
+    /// any other non-2xx status
+    HttpError,
+    /// 2xx but the body was not the JSON shape this client expects
+    MalformedResponse,
+};
+
+/// A short, operator-facing description. Never includes the read key.
+const char *describeApiStatus(ApiStatus status);
+
+struct SlotInfo {
+    /// LiveKit participant identity -- this is what the session wrapper
+    /// subscribes to, and what gets persisted in the OBS source settings.
+    std::string identity;
+    /// Human label for the dropdown; the server falls back to identity.
+    std::string display_name;
+    /// Currently publishing camera video.
+    bool live = false;
+};
+
+struct SlotsResult {
+    ApiStatus status = ApiStatus::InvalidConfig;
+    /// Detail for logs/UI. Never contains the read key.
+    std::string message;
+    std::vector<SlotInfo> slots;
+
+    bool ok() const { return status == ApiStatus::Ok; }
+};
+
+struct TokenResult {
+    ApiStatus status = ApiStatus::InvalidConfig;
+    std::string message;
+    /// LiveKit JWT for a hidden, subscribe-only participant.
+    std::string lk_token;
+    /// LiveKit websocket URL to connect to.
+    std::string ws_url;
+    /// The obs:<slug>:<nonce> identity the server minted for us.
+    std::string identity;
+
+    bool ok() const { return status == ApiStatus::Ok; }
+};
+
+class ApiClient {
+public:
+    /// Takes ownership of the HTTP client, so tests can inject a fake.
+    explicit ApiClient(std::shared_ptr<HttpClient> http);
+
+    /// @param timeout_ms whole-request timeout. Kept as a parameter because
+    /// the properties dialog's "Refresh" button runs on OBS's UI thread with
+    /// an operator waiting, and must give up sooner than a background
+    /// reconnect would.
+    SlotsResult fetchSlots(const ConnectionConfig &config, int timeout_ms = 10000) const;
+    TokenResult requestToken(const ConnectionConfig &config, int timeout_ms = 10000) const;
+
+    /// Accepts what an operator would actually paste: a bare hostname, a URL
+    /// with a trailing slash, extra whitespace. Returns an empty string if
+    /// nothing usable is left. Defaults to https:// when no scheme is given,
+    /// because the read key must never be sent in the clear by accident.
+    static std::string normalizeServerUrl(const std::string &raw);
+
+    /// Exposed for tests and for logging: the exact URL a call will hit,
+    /// with the read key replaced by "***".
+    static std::string redactedUrl(const std::string &url);
+
+    /// Scrubs "access_token=<value>" and "key=<value>" out of arbitrary
+    /// text -- not necessarily a bare URL/query string -- replacing each
+    /// value with "<redacted>". Unlike redactedUrl (which only has to
+    /// handle "&"-delimited query parameters), a value here can be followed
+    /// by a quote or whitespace, because the text this scrubs is a free-form
+    /// log line that may merely *contain* a URL. Used by the OBS adapter's
+    /// LiveKit SDK log bridge: LiveKit's signaling URL carries the access
+    /// token as a query parameter, and the SDK's own log lines could
+    /// include it.
+    static std::string redactSensitiveParams(const std::string &text);
+
+private:
+    std::shared_ptr<HttpClient> http_;
+};
+
+} // namespace stplugin

core/include/stplugin/core.h

@@ -20,32 +20,23 @@ with this program. If not, see <https://www.gnu.org/licenses/>
 
 #include <string>
 
-// C++ API for the core library. Per the design doc
+// The small shared pieces of the core library: its version string, and the
-// (docs/superpowers/specs/2026-09-06-obs-camera-plugin-design.md in the
+// streamer-tools connection settings that both the API client and the OBS
-// streamer-tools repo), this library will eventually own: streamer-tools
+// adapter pass around. Everything substantial lives in its own header --
-// API auth, LiveKit FFI session management (connect, subscribe, decode,
+// api_client.h, session.h, http.h, json.h -- and none of it depends on OBS,
-// reconnect), and frame callbacks -- all with zero OBS dependency, so it
+// so the whole library builds and tests headlessly on all three platforms.
-// can be built and tested headlessly.
-//
-// THIS IS SCAFFOLDING. Nothing below talks to a real server or to
-// livekit-ffi yet. It exists to prove the core-library/OBS-adapter split
-// builds, links, and is unit-testable, ahead of a later phase that
-// implements the real logic.
 
 namespace stplugin {
 
-// Returns the core library's version string. Placeholder for a real
+// The core library's version string, injected by CMake from the top-level
-// version scheme once the library does something.
+// project() version, so what OBS logs on load is the actual build.
 const char *core_version();
 
-// Minimal connection configuration the future core library will use to
+// What an operator types into the source's properties, and what ApiClient
-// authenticate against the streamer-tools API
+// needs to reach the two read-key-scoped endpoints in
-// (see apps/server/src/rooms/join.routes.ts and
+// apps/server/src/obs/plugin.routes.ts (streamer-tools repo). The read key is
-// apps/server/src/livekit/tokens.ts in the streamer-tools repo for the
+// a credential: it is masked in the properties UI and never logged (see
-// existing read-key-authed token pattern this will follow) and mint a
+// ApiClient::redactedUrl).
-// scoped LiveKit subscriber token. Validation here is intentionally
-// trivial -- it exists to prove the core library is unit-testable
-// headlessly, not to implement the real API client.
 struct ConnectionConfig {
     std::string server_url;
     std::string room_slug;

core/include/stplugin/core_c.h

@@ -18,15 +18,13 @@ with this program. If not, see <https://www.gnu.org/licenses/>
 
 #pragma once
 
-// Minimal C ABI surface of the core library, for the OBS adapter (plain
+// A minimal C ABI over the core library's version string.
-// C, per the obs-plugintemplate convention) to call into the core
-// library (C++) without needing a C++ compiler in that translation unit.
 //
-// This mirrors the boundary the real integration will cross in the
+// The OBS adapter is C++ and calls stplugin::core_version() directly, so
-// other direction: livekit-ffi is a Rust library exposing a C ABI that
+// nothing in this repository needs this header today. It is kept because it
-// the C++ core library will link against. Proving a small, deliberate
+// is the seam a plain-C consumer would use, and because the unit tests assert
-// C ABI seam works cleanly here is part of what this scaffold is for.
+// the two entry points agree -- which is a cheap check that the C++ library
-
+// really is linkable from a C translation unit.
 #ifdef __cplusplus
 extern "C" {
 #endif

core/include/stplugin/http.h

@@ -0,0 +1,78 @@
+/*
+streamer-tools OBS Camera Plugin - HTTP client interface
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#pragma once
+
+// A two-method HTTP interface, injectable so ApiClient can be unit-tested
+// without a network (mirroring the streamer-tools repo's injectable-deps
+// convention, per the design doc's Testing section).
+//
+// Backends, chosen per platform so no third-party HTTP dependency has to be
+// built on any of the three CI runners:
+//   - Linux/macOS: libcurl. Already present on both (client-sdk-cpp's own
+//     liblivekit links libcurl on Linux, and macOS ships libcurl in the SDK).
+//   - Windows: WinHTTP, which ships with the OS and handles TLS through
+//     SChannel -- avoiding an OpenSSL or curl build on the Windows runner.
+
+#include <map>
+#include <string>
+
+namespace stplugin {
+
+struct HttpResponse {
+    /// HTTP status code, or 0 when the request never completed (DNS failure,
+    /// TLS failure, timeout, ...). Callers must check `network_error` first.
+    long status = 0;
+
+    /// Response body. May be empty, may be arbitrary bytes: never assume it
+    /// parses as JSON.
+    std::string body;
+
+    /// Empty on success. Non-empty means the request did not complete and
+    /// `status`/`body` are meaningless.
+    std::string network_error;
+
+    bool ok() const { return network_error.empty(); }
+};
+
+struct HttpRequest {
+    std::string method = "GET";
+    std::string url;
+    std::string body;
+    std::string content_type;
+
+    /// Whole-request timeout. Kept short: this runs on OBS's UI thread when
+    /// the properties dropdown is refreshed, and on the source's own worker
+    /// thread when a token is minted.
+    int timeout_ms = 10000;
+};
+
+class HttpClient {
+public:
+    virtual ~HttpClient() = default;
+    virtual HttpResponse send(const HttpRequest &request) = 0;
+};
+
+/// Percent-encode a string for use in a URL query value.
+std::string urlEncode(const std::string &value);
+
+/// Construct the platform's real HTTP client. Returns nullptr if no backend
+/// was compiled in.
+HttpClient *createPlatformHttpClient();
+
+} // namespace stplugin

core/include/stplugin/json.h

@@ -0,0 +1,106 @@
+/*
+streamer-tools OBS Camera Plugin - minimal JSON reader
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#pragma once
+
+// A deliberately small, strict, allocation-bounded JSON reader.
+//
+// Why hand-rolled rather than vendoring nlohmann/json: the only JSON this
+// plugin ever parses is two small, fixed-shape responses from its own
+// server (apps/server/src/obs/plugin.routes.ts in the streamer-tools repo),
+// and the parser has to build unmodified on three platforms with no package
+// manager step in CI. The scope is small enough to test exhaustively --
+// including the malformed inputs a compromised or misconfigured endpoint
+// could return, which is the case that must not crash or hang OBS.
+//
+// Properties this parser guarantees, all covered by core/tests/test_json.cpp:
+//   - never throws; every failure is reported as Value::invalid()
+//   - bounded recursion (kMaxDepth) so nesting cannot blow the stack
+//   - trailing garbage after the top-level value is an error
+//   - accessors on a wrong-typed value return the caller's default rather
+//     than aborting, so callers can be written without type interrogation
+
+#include <cstdint>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace stplugin {
+namespace json {
+
+/// Maximum nesting depth accepted by parse(). Any deeper input is rejected
+/// as invalid rather than recursed into.
+constexpr int kMaxDepth = 32;
+
+class Value {
+public:
+    enum class Type { Invalid, Null, Bool, Number, String, Array, Object };
+
+    Value() = default;
+
+    static Value invalid() { return Value(); }
+    static Value makeNull();
+    static Value makeBool(bool v);
+    static Value makeNumber(double v);
+    static Value makeString(std::string v);
+    static Value makeArray(std::vector<Value> v);
+    static Value makeObject(std::map<std::string, Value> v);
+
+    Type type() const { return type_; }
+    bool valid() const { return type_ != Type::Invalid; }
+    bool isNull() const { return type_ == Type::Null; }
+    bool isBool() const { return type_ == Type::Bool; }
+    bool isNumber() const { return type_ == Type::Number; }
+    bool isString() const { return type_ == Type::String; }
+    bool isArray() const { return type_ == Type::Array; }
+    bool isObject() const { return type_ == Type::Object; }
+
+    /// Object member lookup. Returns invalid() for a missing key or when this
+    /// value is not an object.
+    const Value &operator[](const std::string &key) const;
+
+    /// Array element access. Returns invalid() when out of range or when this
+    /// value is not an array.
+    const Value &at(std::size_t index) const;
+
+    std::size_t size() const;
+
+    /// Typed accessors. Each returns `fallback` when this value is missing or
+    /// of the wrong type, so callers never have to check first.
+    std::string asString(const std::string &fallback = std::string()) const;
+    bool asBool(bool fallback = false) const;
+    double asNumber(double fallback = 0.0) const;
+
+    const std::vector<Value> &elements() const { return array_; }
+
+private:
+    Type type_ = Type::Invalid;
+    bool bool_ = false;
+    double number_ = 0.0;
+    std::string string_;
+    std::vector<Value> array_;
+    std::map<std::string, Value> object_;
+};
+
+/// Parse a complete JSON document. Returns Value::invalid() on any syntax
+/// error, on trailing non-whitespace content, or on excessive nesting.
+/// Never throws.
+Value parse(const std::string &text);
+
+} // namespace json
+} // namespace stplugin

core/include/stplugin/session.h

@@ -0,0 +1,118 @@
+/*
+streamer-tools OBS Camera Plugin - LiveKit session wrapper
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#pragma once
+
+#include <memory>
+#include <string>
+
+#include "stplugin/session_types.h"
+
+namespace stplugin {
+
+struct SessionConfig {
+    /// LiveKit websocket URL, from POST /api/obs/:slug/token.
+    std::string ws_url;
+    /// LiveKit JWT, from the same call.
+    std::string token;
+    /// The slot's participant identity to subscribe to.
+    std::string participant_identity;
+
+    /// Pixel format requested from the SDK. I420 costs no conversion on
+    /// either side.
+    PixelFormat video_format = PixelFormat::I420;
+
+    /// Ring-buffer depth for decoded video. Non-zero means the SDK drops the
+    /// OLDEST frame when the queue is full, which is the structural answer to
+    /// the stale-frame-after-publisher-swap bug that motivated this plugin
+    /// (see the design doc's Approach section): a stalled consumer can only
+    /// ever fall this far behind, and what it then sees is the newest frame,
+    /// not a backlog.
+    std::size_t video_queue_capacity = 3;
+
+    /// Same for audio. A little deeper because audio frames are 10ms each.
+    std::size_t audio_queue_capacity = 20;
+
+    bool subscribe_audio = true;
+
+    /// How long connect() waits for the room to come up before giving up.
+    int connect_timeout_ms = 15000;
+};
+
+/// Wraps livekit::Room for exactly one subscribed slot.
+///
+/// Threading contract, which the OBS adapter depends on:
+///   - connect() and disconnect() are blocking and must be called from an
+///     ordinary thread. They must NOT be called from inside a handler this
+///     class invokes: the SDK documents that Room::disconnect() deadlocks if
+///     called from a room event callback, and Room's own callback registration
+///     is not re-entrant either.
+///   - The video and audio handlers are invoked on dedicated reader threads,
+///     one per track. Frame pointers are valid only for the duration of the
+///     call.
+///   - The state handler is invoked from whichever thread observed the
+///     change. It must not block and must not call back into this object.
+///   - All handlers must be installed before connect(); they are not
+///     synchronised against a running session.
+class LiveKitSession {
+public:
+    LiveKitSession();
+    ~LiveKitSession();
+
+    LiveKitSession(const LiveKitSession &) = delete;
+    LiveKitSession &operator=(const LiveKitSession &) = delete;
+
+    void setVideoHandler(VideoFrameHandler handler);
+    void setAudioHandler(AudioFrameHandler handler);
+    void setStateHandler(SessionStateHandler handler);
+
+    /// Connect and start subscribing. Returns true once the room is up; the
+    /// selected slot's tracks may still arrive later (or not at all, if the
+    /// camera is dark), which is reported through hasVideo()/the state
+    /// handler rather than as a connect failure.
+    bool connect(const SessionConfig &config);
+
+    /// Tear everything down. Safe to call when never connected, and safe to
+    /// call twice.
+    void disconnect();
+
+    SessionState state() const;
+    std::string stateDetail() const;
+    bool hasVideo() const;
+    bool hasAudio() const;
+    /// True when connected but the slot is not publishing: the source should
+    /// show its placeholder, not an error.
+    bool waitingForCamera() const;
+
+    /// Monotonic counters, for logging and for the adapter to tell "connected
+    /// but silent" from "never started".
+    std::uint64_t videoFrameCount() const;
+    std::uint64_t audioFrameCount() const;
+
+    /// Process-wide SDK init/teardown. Reference-counted, so several sources
+    /// can each hold one. The OBS adapter calls these from obs_module_load /
+    /// obs_module_unload.
+    static void globalInitialize();
+    static void globalShutdown();
+
+private:
+    struct Impl;
+    std::unique_ptr<Impl> impl_;
+};
+
+} // namespace stplugin

core/include/stplugin/session_types.h

@@ -0,0 +1,187 @@
+/*
+streamer-tools OBS Camera Plugin - session types and pure session logic
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#pragma once
+
+// Everything in this header is deliberately free of both LiveKit and OBS
+// types. That is what makes the session's decision-making unit-testable
+// headlessly: the parts of LiveKitSession that can go wrong without a server
+// -- which state a sequence of room events leaves us in, whether a given
+// published track is the one we want, and whether a frame's geometry is
+// self-consistent -- all live here, and LiveKitSession is the (much thinner)
+// piece that wires real SDK callbacks into them.
+
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <string>
+
+namespace stplugin {
+
+// ---------------------------------------------------------------------------
+// Media description (mirrors of the LiveKit enums, converted at the boundary)
+// ---------------------------------------------------------------------------
+
+enum class MediaKind { Unknown, Audio, Video };
+
+enum class MediaSource { Unknown, Camera, Microphone, Screenshare, ScreenshareAudio, Other };
+
+/// Pixel formats this plugin is willing to receive. I420 is the default
+/// because it is what a WebRTC decoder produces and what OBS accepts
+/// natively, so neither side pays for a conversion.
+enum class PixelFormat { I420, NV12, BGRA };
+
+const char *describePixelFormat(PixelFormat format);
+
+/// Number of planes a format uses (3 for I420, 2 for NV12, 1 for BGRA).
+int planeCount(PixelFormat format);
+
+/// Total bytes a tightly-packed frame of this format and geometry occupies.
+/// Returns 0 for non-positive dimensions. Used to reject a frame whose
+/// buffer does not match its claimed size before its pointers reach OBS.
+std::size_t expectedFrameBytes(PixelFormat format, int width, int height);
+
+// ---------------------------------------------------------------------------
+// Track selection
+// ---------------------------------------------------------------------------
+
+/// Does this published track belong to the slot we were asked to show, and is
+/// it the camera (never the screenshare)?
+///
+/// streamer-tools publishes cameras as Track.Source.Camera and screenshares
+/// as Track.Source.ScreenShare (apps/web/src/avatar/publish.ts), so the
+/// source is the reliable discriminator. A track that reports no source at
+/// all is accepted on kind alone rather than dropped, since an unknown source
+/// on a video track from the right participant is far more likely to be a
+/// camera than anything else.
+bool isWantedVideoTrack(const std::string &wanted_identity, const std::string &track_identity, MediaKind kind,
+                        MediaSource source);
+
+/// Same, for the slot's microphone.
+bool isWantedAudioTrack(const std::string &wanted_identity, const std::string &track_identity, MediaKind kind,
+                        MediaSource source);
+
+// ---------------------------------------------------------------------------
+// Session state
+// ---------------------------------------------------------------------------
+
+enum class SessionState {
+    /// Never asked to connect, or fully torn down.
+    Idle,
+    /// connect() is in flight.
+    Connecting,
+    /// Signalling is up. Says nothing about whether video is arriving --
+    /// that is what hasVideo() is for.
+    Connected,
+    /// The SDK is re-establishing the connection on its own.
+    Reconnecting,
+    /// The room ended: either we disconnected, or the server did.
+    Disconnected,
+    /// connect() failed, or the session died in a way retrying will not fix
+    /// (a rejected token, a duplicate identity).
+    Failed,
+};
+
+const char *describeSessionState(SessionState state);
+
+/// The pure state machine behind LiveKitSession. Not thread-safe on its own;
+/// LiveKitSession owns the lock.
+///
+/// It exists separately so the transitions that matter operationally -- a
+/// publisher swap must not read as a failure, a reconnect must not read as a
+/// fresh connection, a failure detail must survive until the next connect --
+/// can be tested without a LiveKit server.
+class SessionStateMachine {
+public:
+    SessionState state() const { return state_; }
+
+    /// Human-readable reason for the current state. Empty when there is
+    /// nothing to say. Never contains a token or read key.
+    const std::string &detail() const { return detail_; }
+
+    /// Whether a video track is currently attached and delivering.
+    bool hasVideo() const { return has_video_; }
+    bool hasAudio() const { return has_audio_; }
+
+    /// True when the source should be showing its "waiting for camera"
+    /// placeholder rather than an error: we are up, the slot just isn't live.
+    bool waitingForCamera() const;
+
+    void onConnectRequested();
+    void onConnectSucceeded();
+    void onConnectFailed(const std::string &reason);
+    void onReconnecting();
+    void onReconnected();
+    /// The server (or the SDK) ended the room. `fatal` distinguishes a reason
+    /// that retrying cannot fix from an ordinary drop.
+    void onRoomEnded(const std::string &reason, bool fatal);
+    void onLocalDisconnect();
+
+    void onVideoAttached();
+    void onVideoDetached();
+    void onAudioAttached();
+    void onAudioDetached();
+
+private:
+    SessionState state_ = SessionState::Idle;
+    std::string detail_;
+    bool has_video_ = false;
+    bool has_audio_ = false;
+};
+
+// ---------------------------------------------------------------------------
+// Frames handed to the OBS adapter
+// ---------------------------------------------------------------------------
+
+struct VideoPlane {
+    const std::uint8_t *data = nullptr;
+    std::uint32_t stride = 0;
+    std::uint32_t size = 0;
+};
+
+/// A decoded video frame. All pointers are owned by the SDK and are valid
+/// only for the duration of the callback -- copy or consume synchronously.
+struct VideoFrameData {
+    int width = 0;
+    int height = 0;
+    PixelFormat format = PixelFormat::I420;
+    const std::uint8_t *data = nullptr;
+    std::size_t size = 0;
+    VideoPlane planes[4];
+    int plane_count = 0;
+    /// WebRTC capture-time timestamp, microseconds.
+    std::int64_t timestamp_us = 0;
+};
+
+/// Interleaved int16 PCM. client-sdk-cpp's AudioFrameCallback carries no
+/// timestamp, so the adapter stamps arrival time itself -- see the design
+/// doc's "Audio/video sync verification" note, which flags that as an
+/// assumption to check on real hardware rather than a guarantee.
+struct AudioFrameData {
+    const std::int16_t *samples = nullptr;
+    std::size_t sample_count = 0;
+    int sample_rate = 0;
+    int channels = 0;
+    int samples_per_channel = 0;
+};
+
+using VideoFrameHandler = std::function<void(const VideoFrameData &)>;
+using AudioFrameHandler = std::function<void(const AudioFrameData &)>;
+using SessionStateHandler = std::function<void(SessionState state, const std::string &detail)>;
+
+} // namespace stplugin

core/src/api_client.cpp

@@ -0,0 +1,252 @@
+/*
+streamer-tools OBS Camera Plugin - streamer-tools API client
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#include "stplugin/api_client.h"
+
+#include "stplugin/json.h"
+
+#include <utility>
+
+namespace stplugin {
+
+namespace {
+
+std::string trim(const std::string &s)
+{
+    std::size_t begin = 0;
+    std::size_t end = s.size();
+    auto is_space = [](char c) { return c == ' ' || c == '\t' || c == '\r' || c == '\n'; };
+    while (begin < end && is_space(s[begin]))
+        ++begin;
+    while (end > begin && is_space(s[end - 1]))
+        --end;
+    return s.substr(begin, end - begin);
+}
+
+/// Map a completed HTTP response onto the shared status codes. Returns
+/// ApiStatus::Ok when the caller should go on to parse the body.
+ApiStatus classify(const HttpResponse &response, std::string &message)
+{
+    if (!response.ok()) {
+        message = response.network_error;
+        return ApiStatus::NetworkError;
+    }
+    if (response.status >= 200 && response.status < 300)
+        return ApiStatus::Ok;
+    if (response.status == 404) {
+        message = "unknown room slug, or the read key is wrong or has been rotated";
+        return ApiStatus::NotFound;
+    }
+    if (response.status == 503) {
+        message = "the streamer-tools server has no LiveKit credentials configured";
+        return ApiStatus::Unavailable;
+    }
+    message = "HTTP " + std::to_string(response.status);
+    return ApiStatus::HttpError;
+}
+
+std::string buildUrl(const ConnectionConfig &config, const char *suffix)
+{
+    return ApiClient::normalizeServerUrl(config.server_url) + "/api/obs/" +
+           urlEncode(trim(config.room_slug)) + suffix + "?key=" + urlEncode(trim(config.read_key));
+}
+
+} // namespace
+
+const char *describeApiStatus(ApiStatus status)
+{
+    switch (status) {
+    case ApiStatus::Ok: return "ok";
+    case ApiStatus::InvalidConfig: return "server URL, room slug and read key are all required";
+    case ApiStatus::NetworkError: return "could not reach the streamer-tools server";
+    case ApiStatus::NotFound: return "room not found, or the read key is wrong";
+    case ApiStatus::Unavailable: return "server has no LiveKit configured";
+    case ApiStatus::HttpError: return "unexpected response from the streamer-tools server";
+    case ApiStatus::MalformedResponse: return "unreadable response from the streamer-tools server";
+    }
+    return "unknown error";
+}
+
+ApiClient::ApiClient(std::shared_ptr<HttpClient> http) : http_(std::move(http)) {}
+
+std::string ApiClient::normalizeServerUrl(const std::string &raw)
+{
+    std::string url = trim(raw);
+    if (url.empty())
+        return url;
+
+    // A bare "streamers.example.com" is what an operator will paste half the
+    // time. Defaulting to https (never http) keeps the read key off the wire
+    // in the clear.
+    const bool has_scheme = url.compare(0, 7, "http://") == 0 || url.compare(0, 8, "https://") == 0;
+    if (!has_scheme)
+        url = "https://" + url;
+    // An explicit "http://..." is left as-is on purpose: an operator who
+    // typed the scheme out has made a deliberate (if inadvisable) choice,
+    // and this function's job is only to supply a sane default, not to
+    // second-guess an explicit one.
+
+    while (!url.empty() && url.back() == '/')
+        url.pop_back();
+
+    // "https://" with nothing after it is not a server.
+    if (url == "https:/" || url == "https:" || url == "http:/" || url == "http:" ||
+        url == "https://" || url == "http://")
+        return std::string();
+
+    return url;
+}
+
+// No current call site logs a request URL (the OBS adapter only logs
+// ws_url/status text, never the streamer-tools API request URL itself) --
+// this exists as a deliberate guard rail for whenever request-URL logging
+// is added later, so the read key can never be pasted into an OBS log by
+// accident. Not dead code to be deleted.
+std::string ApiClient::redactedUrl(const std::string &url)
+{
+    const std::size_t at = url.find("key=");
+    if (at == std::string::npos)
+        return url;
+    const std::size_t value = at + 4;
+    std::size_t end = url.find('&', value);
+    if (end == std::string::npos)
+        end = url.size();
+    return url.substr(0, value) + "***" + url.substr(end);
+}
+
+std::string ApiClient::redactSensitiveParams(const std::string &text)
+{
+    static const char *const kParams[] = {"access_token=", "key="};
+
+    std::string out = text;
+    for (const char *param : kParams) {
+        const std::size_t param_len = std::string(param).size();
+        std::size_t pos = 0;
+        while ((pos = out.find(param, pos)) != std::string::npos) {
+            const std::size_t value_start = pos + param_len;
+            std::size_t value_end = value_start;
+            // A value ends at the next query-string delimiter, a quote (the
+            // URL is often embedded in a quoted/bracketed log line), or
+            // whitespace -- whichever comes first -- or at the end of the
+            // string.
+            while (value_end < out.size()) {
+                const char c = out[value_end];
+                if (c == '&' || c == '"' || c == '\'' || c == ' ' || c == '\t' || c == '\n' ||
+                    c == '\r' || c == ')' || c == ']')
+                    break;
+                ++value_end;
+            }
+            const std::string replacement = "<redacted>";
+            out.replace(value_start, value_end - value_start, replacement);
+            pos = value_start + replacement.size();
+        }
+    }
+    return out;
+}
+
+SlotsResult ApiClient::fetchSlots(const ConnectionConfig &config, int timeout_ms) const
+{
+    SlotsResult result;
+    if (!config.is_valid() || normalizeServerUrl(config.server_url).empty() || !http_) {
+        result.status = ApiStatus::InvalidConfig;
+        result.message = describeApiStatus(ApiStatus::InvalidConfig);
+        return result;
+    }
+
+    HttpRequest request;
+    request.method = "GET";
+    request.url = buildUrl(config, "/slots");
+    request.timeout_ms = timeout_ms;
+
+    const HttpResponse response = http_->send(request);
+    const ApiStatus status = classify(response, result.message);
+    if (status != ApiStatus::Ok) {
+        result.status = status;
+        return result;
+    }
+
+    const json::Value root = json::parse(response.body);
+    const json::Value &slots = root["slots"];
+    if (!root.isObject() || !slots.isArray()) {
+        result.status = ApiStatus::MalformedResponse;
+        result.message = "expected a JSON object with a \"slots\" array";
+        return result;
+    }
+
+    for (const json::Value &entry : slots.elements()) {
+        // A slot without an identity is unusable -- it is what the session
+        // wrapper subscribes by -- so skip it rather than surfacing a
+        // dropdown row that can never connect. Anything else is best-effort:
+        // a missing displayName falls back to the identity exactly as the
+        // server itself does.
+        const std::string identity = entry["identity"].asString();
+        if (identity.empty())
+            continue;
+        SlotInfo slot;
+        slot.identity = identity;
+        slot.display_name = entry["displayName"].asString(identity);
+        if (slot.display_name.empty())
+            slot.display_name = identity;
+        slot.live = entry["live"].asBool(false);
+        result.slots.push_back(std::move(slot));
+    }
+
+    result.status = ApiStatus::Ok;
+    return result;
+}
+
+TokenResult ApiClient::requestToken(const ConnectionConfig &config, int timeout_ms) const
+{
+    TokenResult result;
+    if (!config.is_valid() || normalizeServerUrl(config.server_url).empty() || !http_) {
+        result.status = ApiStatus::InvalidConfig;
+        result.message = describeApiStatus(ApiStatus::InvalidConfig);
+        return result;
+    }
+
+    HttpRequest request;
+    request.method = "POST";
+    request.url = buildUrl(config, "/token");
+    request.content_type = "application/json";
+    request.body = "{}";
+    request.timeout_ms = timeout_ms;
+
+    const HttpResponse response = http_->send(request);
+    const ApiStatus status = classify(response, result.message);
+    if (status != ApiStatus::Ok) {
+        result.status = status;
+        return result;
+    }
+
+    const json::Value root = json::parse(response.body);
+    const std::string token = root["lkToken"].asString();
+    const std::string ws_url = root["wsUrl"].asString();
+    if (!root.isObject() || token.empty() || ws_url.empty()) {
+        result.status = ApiStatus::MalformedResponse;
+        result.message = "expected a JSON object with non-empty \"lkToken\" and \"wsUrl\"";
+        return result;
+    }
+
+    result.lk_token = token;
+    result.ws_url = ws_url;
+    result.identity = root["identity"].asString();
+    result.status = ApiStatus::Ok;
+    return result;
+}
+
+} // namespace stplugin

core/src/core.cpp

@@ -22,7 +22,9 @@ with this program. If not, see <https://www.gnu.org/licenses/>
 namespace stplugin {
 
 const char *core_version() {
-    return "0.0.1-scaffold";
+    // Injected by CMake from the top-level project() version, so the string
+    // OBS logs on load is the actual build, not a hand-maintained literal.
+    return STPLUGIN_CORE_VERSION;
 }
 
 bool ConnectionConfig::is_valid() const {

core/src/http_common.cpp

@@ -0,0 +1,46 @@
+/*
+streamer-tools OBS Camera Plugin - HTTP helpers shared by all backends
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#include "stplugin/http.h"
+
+namespace stplugin {
+
+// Hand-rolled rather than curl_easy_escape so the WinHTTP backend gets the
+// same behaviour, and so this is testable without a live HTTP client.
+// Unreserved set per RFC 3986 section 2.3.
+std::string urlEncode(const std::string &value)
+{
+    static const char *kHex = "0123456789ABCDEF";
+    std::string out;
+    out.reserve(value.size());
+    for (const char raw : value) {
+        const unsigned char c = static_cast<unsigned char>(raw);
+        const bool unreserved = (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
+                                (c >= '0' && c <= '9') || c == '-' || c == '_' || c == '.' || c == '~';
+        if (unreserved) {
+            out.push_back(static_cast<char>(c));
+        } else {
+            out.push_back('%');
+            out.push_back(kHex[c >> 4]);
+            out.push_back(kHex[c & 0x0F]);
+        }
+    }
+    return out;
+}
+
+} // namespace stplugin

core/src/http_curl.cpp

@@ -0,0 +1,146 @@
+/*
+streamer-tools OBS Camera Plugin - libcurl HTTP backend (Linux/macOS)
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#include "stplugin/http.h"
+
+#include <curl/curl.h>
+
+#include <cstddef>
+#include <mutex>
+
+namespace stplugin {
+
+namespace {
+
+/// Hard cap on a response body. The two endpoints this client talks to return
+/// a few hundred bytes; anything larger is a misconfigured proxy or a wrong
+/// URL, and must not be allowed to grow OBS's heap without bound.
+constexpr std::size_t kMaxResponseBytes = 4u * 1024u * 1024u;
+
+struct WriteContext {
+    std::string body;
+    bool overflowed = false;
+};
+
+std::size_t writeCallback(char *ptr, std::size_t size, std::size_t nmemb, void *userdata)
+{
+    auto *ctx = static_cast<WriteContext *>(userdata);
+    const std::size_t bytes = size * nmemb;
+    if (ctx->body.size() + bytes > kMaxResponseBytes) {
+        ctx->overflowed = true;
+        return 0; // aborts the transfer with CURLE_WRITE_ERROR
+    }
+    ctx->body.append(ptr, bytes);
+    return bytes;
+}
+
+/// curl_global_init is not thread-safe and must run once per process before
+/// any easy handle is created. OBS may create several sources concurrently.
+void ensureCurlGlobalInit()
+{
+    static std::once_flag once;
+    std::call_once(once, [] { curl_global_init(CURL_GLOBAL_DEFAULT); });
+}
+
+class CurlHttpClient : public HttpClient {
+public:
+    HttpResponse send(const HttpRequest &request) override
+    {
+        ensureCurlGlobalInit();
+
+        HttpResponse response;
+        CURL *curl = curl_easy_init();
+        if (!curl) {
+            response.network_error = "curl_easy_init failed";
+            return response;
+        }
+
+        WriteContext ctx;
+        struct curl_slist *headers = nullptr;
+
+        curl_easy_setopt(curl, CURLOPT_URL, request.url.c_str());
+        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writeCallback);
+        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ctx);
+        curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS, static_cast<long>(request.timeout_ms));
+        curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS, static_cast<long>(request.timeout_ms));
+        // Redirects are never legitimate here: this client only ever talks to
+        // two fixed, first-party streamer-tools API endpoints, and the read
+        // key travels as a URL query parameter (see api_client.cpp). Blindly
+        // following a redirect -- including an HTTPS->HTTP downgrade, which
+        // curl does not refuse by default -- would hand that key to whatever
+        // host the redirect points at. A redirect from our own server is a
+        // configuration error, so treat it as a failed request instead of
+        // silently following it. This also brings this backend in line with
+        // http_winhttp.cpp, which already refuses HTTPS->HTTP downgrades by
+        // default.
+        curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 0L);
+        curl_easy_setopt(curl, CURLOPT_USERAGENT, "streamer-tools-obs-plugin/1.0");
+        // NOSIGNAL is required whenever curl is used off the main thread:
+        // without it curl installs a SIGALRM handler for DNS timeouts, which
+        // is process-global and would be a rude thing to do inside OBS.
+        curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1L);
+        // TLS verification stays on. The read key is a credential; sending it
+        // to an unverified host is exactly the failure this must not have.
+        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
+        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
+
+        if (request.method == "POST") {
+            curl_easy_setopt(curl, CURLOPT_POST, 1L);
+            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, request.body.c_str());
+            curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, static_cast<long>(request.body.size()));
+        } else if (request.method != "GET") {
+            curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, request.method.c_str());
+        }
+
+        if (!request.content_type.empty()) {
+            const std::string header = "Content-Type: " + request.content_type;
+            headers = curl_slist_append(headers, header.c_str());
+        }
+        // Fastify answers a bare POST with no body fine, but some proxies
+        // insert an Expect: 100-continue round trip; suppress it.
+        headers = curl_slist_append(headers, "Expect:");
+        if (headers)
+            curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
+
+        const CURLcode rc = curl_easy_perform(curl);
+        if (rc == CURLE_OK) {
+            long status = 0;
+            curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &status);
+            response.status = status;
+            response.body = std::move(ctx.body);
+        } else if (ctx.overflowed) {
+            response.network_error = "response body exceeded 4 MiB";
+        } else {
+            response.network_error = curl_easy_strerror(rc);
+        }
+
+        if (headers)
+            curl_slist_free_all(headers);
+        curl_easy_cleanup(curl);
+        return response;
+    }
+};
+
+} // namespace
+
+HttpClient *createPlatformHttpClient()
+{
+    return new CurlHttpClient();
+}
+
+} // namespace stplugin

core/src/http_winhttp.cpp

@@ -0,0 +1,208 @@
+/*
+streamer-tools OBS Camera Plugin - WinHTTP backend (Windows)
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+// WinHTTP rather than libcurl on Windows: it ships with the OS, does TLS
+// through SChannel (so no OpenSSL to build or ship), and needs no package
+// manager on the self-hosted `winvm-builder` runner -- which, per the
+// scaffold README, is a bare VM without even cmake preinstalled.
+
+#include "stplugin/http.h"
+
+#include <windows.h>
+#include <winhttp.h>
+
+#include <cstddef>
+#include <string>
+#include <vector>
+
+namespace stplugin {
+
+namespace {
+
+constexpr std::size_t kMaxResponseBytes = 4u * 1024u * 1024u;
+
+std::wstring widen(const std::string &s)
+{
+    if (s.empty())
+        return std::wstring();
+    const int needed = MultiByteToWideChar(CP_UTF8, 0, s.c_str(), static_cast<int>(s.size()), nullptr, 0);
+    if (needed <= 0)
+        return std::wstring();
+    std::wstring out(static_cast<std::size_t>(needed), L'\0');
+    MultiByteToWideChar(CP_UTF8, 0, s.c_str(), static_cast<int>(s.size()), &out[0], needed);
+    return out;
+}
+
+std::string lastErrorMessage(const char *what)
+{
+    return std::string(what) + " failed (GetLastError=" + std::to_string(GetLastError()) + ")";
+}
+
+/// RAII for the three WinHTTP handle kinds, which all close the same way.
+class Handle {
+public:
+    Handle() = default;
+    explicit Handle(HINTERNET h) : h_(h) {}
+    ~Handle()
+    {
+        if (h_)
+            WinHttpCloseHandle(h_);
+    }
+    Handle(const Handle &) = delete;
+    Handle &operator=(const Handle &) = delete;
+
+    void reset(HINTERNET h)
+    {
+        if (h_)
+            WinHttpCloseHandle(h_);
+        h_ = h;
+    }
+    HINTERNET get() const { return h_; }
+    explicit operator bool() const { return h_ != nullptr; }
+
+private:
+    HINTERNET h_ = nullptr;
+};
+
+class WinHttpClient : public HttpClient {
+public:
+    HttpResponse send(const HttpRequest &request) override
+    {
+        HttpResponse response;
+
+        const std::wstring url = widen(request.url);
+        if (url.empty()) {
+            response.network_error = "empty or non-UTF-8 URL";
+            return response;
+        }
+
+        URL_COMPONENTS parts{};
+        parts.dwStructSize = sizeof(parts);
+        wchar_t host[256] = {0};
+        wchar_t path[4096] = {0};
+        wchar_t extra[4096] = {0};
+        parts.lpszHostName = host;
+        parts.dwHostNameLength = static_cast<DWORD>(sizeof(host) / sizeof(host[0]));
+        parts.lpszUrlPath = path;
+        parts.dwUrlPathLength = static_cast<DWORD>(sizeof(path) / sizeof(path[0]));
+        parts.lpszExtraInfo = extra;
+        parts.dwExtraInfoLength = static_cast<DWORD>(sizeof(extra) / sizeof(extra[0]));
+
+        if (!WinHttpCrackUrl(url.c_str(), static_cast<DWORD>(url.size()), 0, &parts)) {
+            response.network_error = lastErrorMessage("WinHttpCrackUrl");
+            return response;
+        }
+        if (parts.nScheme != INTERNET_SCHEME_HTTP && parts.nScheme != INTERNET_SCHEME_HTTPS) {
+            response.network_error = "unsupported URL scheme";
+            return response;
+        }
+
+        Handle session(WinHttpOpen(L"streamer-tools-obs-plugin/1.0", WINHTTP_ACCESS_TYPE_AUTOMATIC_PROXY,
+                                   WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0));
+        if (!session) {
+            response.network_error = lastErrorMessage("WinHttpOpen");
+            return response;
+        }
+
+        const DWORD timeout = static_cast<DWORD>(request.timeout_ms);
+        WinHttpSetTimeouts(session.get(), static_cast<int>(timeout), static_cast<int>(timeout),
+                           static_cast<int>(timeout), static_cast<int>(timeout));
+
+        Handle connect(WinHttpConnect(session.get(), host, parts.nPort, 0));
+        if (!connect) {
+            response.network_error = lastErrorMessage("WinHttpConnect");
+            return response;
+        }
+
+        std::wstring target(path);
+        target += extra;
+
+        const DWORD flags = (parts.nScheme == INTERNET_SCHEME_HTTPS) ? WINHTTP_FLAG_SECURE : 0u;
+        Handle req(WinHttpOpenRequest(connect.get(), widen(request.method).c_str(), target.c_str(), nullptr,
+                                      WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, flags));
+        if (!req) {
+            response.network_error = lastErrorMessage("WinHttpOpenRequest");
+            return response;
+        }
+
+        std::wstring headers;
+        if (!request.content_type.empty())
+            headers = L"Content-Type: " + widen(request.content_type) + L"\r\n";
+
+        const LPCWSTR header_ptr = headers.empty() ? WINHTTP_NO_ADDITIONAL_HEADERS : headers.c_str();
+        const DWORD header_len = headers.empty() ? 0u : static_cast<DWORD>(headers.size());
+
+        void *body_ptr = request.body.empty() ? WINHTTP_NO_REQUEST_DATA
+                                              : const_cast<char *>(request.body.data());
+        const DWORD body_len = static_cast<DWORD>(request.body.size());
+
+        if (!WinHttpSendRequest(req.get(), header_ptr, header_len, body_ptr, body_len, body_len, 0)) {
+            response.network_error = lastErrorMessage("WinHttpSendRequest");
+            return response;
+        }
+        if (!WinHttpReceiveResponse(req.get(), nullptr)) {
+            response.network_error = lastErrorMessage("WinHttpReceiveResponse");
+            return response;
+        }
+
+        DWORD status = 0;
+        DWORD status_size = sizeof(status);
+        if (!WinHttpQueryHeaders(req.get(), WINHTTP_QUERY_STATUS_CODE | WINHTTP_QUERY_FLAG_NUMBER,
+                                 WINHTTP_HEADER_NAME_BY_INDEX, &status, &status_size, WINHTTP_NO_HEADER_INDEX)) {
+            response.network_error = lastErrorMessage("WinHttpQueryHeaders");
+            return response;
+        }
+        response.status = static_cast<long>(status);
+
+        std::string body;
+        for (;;) {
+            DWORD available = 0;
+            if (!WinHttpQueryDataAvailable(req.get(), &available)) {
+                response.network_error = lastErrorMessage("WinHttpQueryDataAvailable");
+                return response;
+            }
+            if (available == 0)
+                break;
+            if (body.size() + available > kMaxResponseBytes) {
+                response.network_error = "response body exceeded 4 MiB";
+                return response;
+            }
+            std::vector<char> chunk(available);
+            DWORD read = 0;
+            if (!WinHttpReadData(req.get(), chunk.data(), available, &read)) {
+                response.network_error = lastErrorMessage("WinHttpReadData");
+                return response;
+            }
+            if (read == 0)
+                break;
+            body.append(chunk.data(), read);
+        }
+
+        response.body = std::move(body);
+        return response;
+    }
+};
+
+} // namespace
+
+HttpClient *createPlatformHttpClient()
+{
+    return new WinHttpClient();
+}
+
+} // namespace stplugin

core/src/json.cpp

@@ -0,0 +1,442 @@
+/*
+streamer-tools OBS Camera Plugin - minimal JSON reader
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#include "stplugin/json.h"
+
+#include <cstdlib>
+#include <cstring>
+
+namespace stplugin {
+namespace json {
+
+namespace {
+const Value &invalidSingleton()
+{
+    static const Value v;
+    return v;
+}
+} // namespace
+
+Value Value::makeNull()
+{
+    Value v;
+    v.type_ = Type::Null;
+    return v;
+}
+
+Value Value::makeBool(bool b)
+{
+    Value v;
+    v.type_ = Type::Bool;
+    v.bool_ = b;
+    return v;
+}
+
+Value Value::makeNumber(double n)
+{
+    Value v;
+    v.type_ = Type::Number;
+    v.number_ = n;
+    return v;
+}
+
+Value Value::makeString(std::string s)
+{
+    Value v;
+    v.type_ = Type::String;
+    v.string_ = std::move(s);
+    return v;
+}
+
+Value Value::makeArray(std::vector<Value> a)
+{
+    Value v;
+    v.type_ = Type::Array;
+    v.array_ = std::move(a);
+    return v;
+}
+
+Value Value::makeObject(std::map<std::string, Value> o)
+{
+    Value v;
+    v.type_ = Type::Object;
+    v.object_ = std::move(o);
+    return v;
+}
+
+const Value &Value::operator[](const std::string &key) const
+{
+    if (type_ != Type::Object)
+        return invalidSingleton();
+    auto it = object_.find(key);
+    if (it == object_.end())
+        return invalidSingleton();
+    return it->second;
+}
+
+const Value &Value::at(std::size_t index) const
+{
+    if (type_ != Type::Array || index >= array_.size())
+        return invalidSingleton();
+    return array_[index];
+}
+
+std::size_t Value::size() const
+{
+    if (type_ == Type::Array)
+        return array_.size();
+    if (type_ == Type::Object)
+        return object_.size();
+    if (type_ == Type::String)
+        return string_.size();
+    return 0;
+}
+
+std::string Value::asString(const std::string &fallback) const
+{
+    return type_ == Type::String ? string_ : fallback;
+}
+
+bool Value::asBool(bool fallback) const
+{
+    return type_ == Type::Bool ? bool_ : fallback;
+}
+
+double Value::asNumber(double fallback) const
+{
+    return type_ == Type::Number ? number_ : fallback;
+}
+
+// ---------------------------------------------------------------------------
+// Parser
+// ---------------------------------------------------------------------------
+
+namespace {
+
+class Parser {
+public:
+    explicit Parser(const std::string &text) : s_(text) {}
+
+    bool parseDocument(Value &out)
+    {
+        skipWs();
+        if (!parseValue(out, 0))
+            return false;
+        skipWs();
+        // Trailing content is an error: "{}garbage" must not silently parse
+        // as an empty object.
+        return pos_ == s_.size();
+    }
+
+private:
+    const std::string &s_;
+    std::size_t pos_ = 0;
+
+    bool eof() const { return pos_ >= s_.size(); }
+    char peek() const { return s_[pos_]; }
+
+    void skipWs()
+    {
+        while (!eof()) {
+            const char c = s_[pos_];
+            if (c == ' ' || c == '\t' || c == '\n' || c == '\r')
+                ++pos_;
+            else
+                break;
+        }
+    }
+
+    bool literal(const char *lit)
+    {
+        const std::size_t n = std::strlen(lit);
+        if (s_.compare(pos_, n, lit) != 0)
+            return false;
+        pos_ += n;
+        return true;
+    }
+
+    bool parseValue(Value &out, int depth)
+    {
+        if (depth > kMaxDepth)
+            return false;
+        if (eof())
+            return false;
+
+        switch (peek()) {
+        case '{':
+            return parseObject(out, depth);
+        case '[':
+            return parseArray(out, depth);
+        case '"': {
+            std::string str;
+            if (!parseString(str))
+                return false;
+            out = Value::makeString(std::move(str));
+            return true;
+        }
+        case 't':
+            if (!literal("true"))
+                return false;
+            out = Value::makeBool(true);
+            return true;
+        case 'f':
+            if (!literal("false"))
+                return false;
+            out = Value::makeBool(false);
+            return true;
+        case 'n':
+            if (!literal("null"))
+                return false;
+            out = Value::makeNull();
+            return true;
+        default:
+            return parseNumber(out);
+        }
+    }
+
+    bool parseObject(Value &out, int depth)
+    {
+        ++pos_; // '{'
+        std::map<std::string, Value> members;
+        skipWs();
+        if (!eof() && peek() == '}') {
+            ++pos_;
+            out = Value::makeObject(std::move(members));
+            return true;
+        }
+        for (;;) {
+            skipWs();
+            std::string key;
+            if (!parseString(key))
+                return false;
+            skipWs();
+            if (eof() || peek() != ':')
+                return false;
+            ++pos_;
+            skipWs();
+            Value v;
+            if (!parseValue(v, depth + 1))
+                return false;
+            members[key] = std::move(v);
+            skipWs();
+            if (eof())
+                return false;
+            if (peek() == ',') {
+                ++pos_;
+                continue;
+            }
+            if (peek() == '}') {
+                ++pos_;
+                out = Value::makeObject(std::move(members));
+                return true;
+            }
+            return false;
+        }
+    }
+
+    bool parseArray(Value &out, int depth)
+    {
+        ++pos_; // '['
+        std::vector<Value> items;
+        skipWs();
+        if (!eof() && peek() == ']') {
+            ++pos_;
+            out = Value::makeArray(std::move(items));
+            return true;
+        }
+        for (;;) {
+            skipWs();
+            Value v;
+            if (!parseValue(v, depth + 1))
+                return false;
+            items.push_back(std::move(v));
+            skipWs();
+            if (eof())
+                return false;
+            if (peek() == ',') {
+                ++pos_;
+                continue;
+            }
+            if (peek() == ']') {
+                ++pos_;
+                out = Value::makeArray(std::move(items));
+                return true;
+            }
+            return false;
+        }
+    }
+
+    bool parseHex4(unsigned &out)
+    {
+        if (pos_ + 4 > s_.size())
+            return false;
+        unsigned value = 0;
+        for (int i = 0; i < 4; ++i) {
+            const char c = s_[pos_ + static_cast<std::size_t>(i)];
+            unsigned digit;
+            if (c >= '0' && c <= '9')
+                digit = static_cast<unsigned>(c - '0');
+            else if (c >= 'a' && c <= 'f')
+                digit = static_cast<unsigned>(c - 'a') + 10u;
+            else if (c >= 'A' && c <= 'F')
+                digit = static_cast<unsigned>(c - 'A') + 10u;
+            else
+                return false;
+            value = (value << 4) | digit;
+        }
+        pos_ += 4;
+        out = value;
+        return true;
+    }
+
+    static void appendUtf8(std::string &out, unsigned cp)
+    {
+        if (cp < 0x80) {
+            out.push_back(static_cast<char>(cp));
+        } else if (cp < 0x800) {
+            out.push_back(static_cast<char>(0xC0u | (cp >> 6)));
+            out.push_back(static_cast<char>(0x80u | (cp & 0x3Fu)));
+        } else if (cp < 0x10000) {
+            out.push_back(static_cast<char>(0xE0u | (cp >> 12)));
+            out.push_back(static_cast<char>(0x80u | ((cp >> 6) & 0x3Fu)));
+            out.push_back(static_cast<char>(0x80u | (cp & 0x3Fu)));
+        } else {
+            out.push_back(static_cast<char>(0xF0u | (cp >> 18)));
+            out.push_back(static_cast<char>(0x80u | ((cp >> 12) & 0x3Fu)));
+            out.push_back(static_cast<char>(0x80u | ((cp >> 6) & 0x3Fu)));
+            out.push_back(static_cast<char>(0x80u | (cp & 0x3Fu)));
+        }
+    }
+
+    bool parseString(std::string &out)
+    {
+        if (eof() || peek() != '"')
+            return false;
+        ++pos_;
+        out.clear();
+        for (;;) {
+            if (eof())
+                return false; // unterminated string
+            const unsigned char c = static_cast<unsigned char>(s_[pos_]);
+            if (c == '"') {
+                ++pos_;
+                return true;
+            }
+            if (c == '\\') {
+                ++pos_;
+                if (eof())
+                    return false;
+                const char esc = s_[pos_++];
+                switch (esc) {
+                case '"': out.push_back('"'); break;
+                case '\\': out.push_back('\\'); break;
+                case '/': out.push_back('/'); break;
+                case 'b': out.push_back('\b'); break;
+                case 'f': out.push_back('\f'); break;
+                case 'n': out.push_back('\n'); break;
+                case 'r': out.push_back('\r'); break;
+                case 't': out.push_back('\t'); break;
+                case 'u': {
+                    unsigned cp = 0;
+                    if (!parseHex4(cp))
+                        return false;
+                    if (cp >= 0xD800 && cp <= 0xDBFF) {
+                        // High surrogate: a low surrogate must follow.
+                        if (pos_ + 1 < s_.size() && s_[pos_] == '\\' && s_[pos_ + 1] == 'u') {
+                            pos_ += 2;
+                            unsigned lo = 0;
+                            if (!parseHex4(lo))
+                                return false;
+                            if (lo < 0xDC00 || lo > 0xDFFF)
+                                return false;
+                            cp = 0x10000u + ((cp - 0xD800u) << 10) + (lo - 0xDC00u);
+                        } else {
+                            return false;
+                        }
+                    } else if (cp >= 0xDC00 && cp <= 0xDFFF) {
+                        return false; // lone low surrogate
+                    }
+                    appendUtf8(out, cp);
+                    break;
+                }
+                default:
+                    return false;
+                }
+                continue;
+            }
+            if (c < 0x20)
+                return false; // raw control character
+            out.push_back(static_cast<char>(c));
+            ++pos_;
+        }
+    }
+
+    bool parseNumber(Value &out)
+    {
+        const std::size_t start = pos_;
+        if (!eof() && peek() == '-')
+            ++pos_;
+        if (eof())
+            return false;
+        if (peek() == '0') {
+            ++pos_;
+        } else if (peek() >= '1' && peek() <= '9') {
+            while (!eof() && peek() >= '0' && peek() <= '9')
+                ++pos_;
+        } else {
+            return false;
+        }
+        if (!eof() && peek() == '.') {
+            ++pos_;
+            if (eof() || peek() < '0' || peek() > '9')
+                return false;
+            while (!eof() && peek() >= '0' && peek() <= '9')
+                ++pos_;
+        }
+        if (!eof() && (peek() == 'e' || peek() == 'E')) {
+            ++pos_;
+            if (!eof() && (peek() == '+' || peek() == '-'))
+                ++pos_;
+            if (eof() || peek() < '0' || peek() > '9')
+                return false;
+            while (!eof() && peek() >= '0' && peek() <= '9')
+                ++pos_;
+        }
+        const std::string token = s_.substr(start, pos_ - start);
+        // strtod is locale-sensitive for the decimal separator, but the
+        // grammar above only ever hands it ASCII digits with a '.', and OBS
+        // does not switch the C locale away from "C". Using strtod rather
+        // than std::stod keeps this noexcept.
+        out = Value::makeNumber(std::strtod(token.c_str(), nullptr));
+        return true;
+    }
+};
+
+} // namespace
+
+Value parse(const std::string &text)
+{
+    Parser p(text);
+    Value v;
+    if (!p.parseDocument(v))
+        return Value::invalid();
+    return v;
+}
+
+} // namespace json
+} // namespace stplugin

core/src/session.cpp

@@ -0,0 +1,742 @@
+/*
+streamer-tools OBS Camera Plugin - LiveKit session wrapper
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#include "stplugin/session.h"
+
+#include <atomic>
+#include <chrono>
+#include <condition_variable>
+#include <deque>
+#include <exception>
+#include <mutex>
+#include <thread>
+#include <utility>
+#include <vector>
+
+#include <livekit/audio_frame.h>
+#include <livekit/audio_stream.h>
+#include <livekit/livekit.h>
+#include <livekit/remote_participant.h>
+#include <livekit/remote_track_publication.h>
+#include <livekit/room.h>
+#include <livekit/room_delegate.h>
+#include <livekit/room_event_types.h>
+#include <livekit/track.h>
+#include <livekit/video_frame.h>
+#include <livekit/video_stream.h>
+
+namespace stplugin {
+
+namespace {
+
+// --- LiveKit <-> plugin type conversion ------------------------------------
+
+MediaKind toMediaKind(livekit::TrackKind kind)
+{
+    switch (kind) {
+    case livekit::TrackKind::KIND_AUDIO: return MediaKind::Audio;
+    case livekit::TrackKind::KIND_VIDEO: return MediaKind::Video;
+    case livekit::TrackKind::KIND_UNKNOWN: break;
+    }
+    return MediaKind::Unknown;
+}
+
+MediaSource toMediaSource(livekit::TrackSource source)
+{
+    switch (source) {
+    case livekit::TrackSource::SOURCE_CAMERA: return MediaSource::Camera;
+    case livekit::TrackSource::SOURCE_MICROPHONE: return MediaSource::Microphone;
+    case livekit::TrackSource::SOURCE_SCREENSHARE: return MediaSource::Screenshare;
+    case livekit::TrackSource::SOURCE_SCREENSHARE_AUDIO: return MediaSource::ScreenshareAudio;
+    case livekit::TrackSource::SOURCE_UNKNOWN: break;
+    }
+    return MediaSource::Unknown;
+}
+
+livekit::VideoBufferType toLiveKitBufferType(PixelFormat format)
+{
+    switch (format) {
+    case PixelFormat::I420: return livekit::VideoBufferType::I420;
+    case PixelFormat::NV12: return livekit::VideoBufferType::NV12;
+    case PixelFormat::BGRA: return livekit::VideoBufferType::BGRA;
+    }
+    return livekit::VideoBufferType::I420;
+}
+
+/// Returns false when the SDK handed us a format the OBS adapter cannot
+/// consume, in which case the caller converts.
+bool fromLiveKitBufferType(livekit::VideoBufferType type, PixelFormat &out)
+{
+    switch (type) {
+    case livekit::VideoBufferType::I420: out = PixelFormat::I420; return true;
+    case livekit::VideoBufferType::NV12: out = PixelFormat::NV12; return true;
+    case livekit::VideoBufferType::BGRA: out = PixelFormat::BGRA; return true;
+    default: return false;
+    }
+}
+
+/// Which disconnect reasons are worth telling the operator "this will not fix
+/// itself" about. Everything else is reported as an ordinary disconnect,
+/// because the SDK's own reconnect logic covers it.
+bool isFatalDisconnect(livekit::DisconnectReason reason)
+{
+    switch (reason) {
+    case livekit::DisconnectReason::DuplicateIdentity:
+    case livekit::DisconnectReason::ParticipantRemoved:
+    case livekit::DisconnectReason::RoomDeleted:
+    case livekit::DisconnectReason::JoinFailure:
+    case livekit::DisconnectReason::UserRejected:
+        return true;
+    default:
+        return false;
+    }
+}
+
+const char *describeDisconnectReason(livekit::DisconnectReason reason)
+{
+    switch (reason) {
+    case livekit::DisconnectReason::Unknown: return "connection lost";
+    case livekit::DisconnectReason::ClientInitiated: return "disconnected";
+    case livekit::DisconnectReason::DuplicateIdentity: return "another client joined with the same identity";
+    case livekit::DisconnectReason::ServerShutdown: return "the LiveKit server is shutting down";
+    case livekit::DisconnectReason::ParticipantRemoved: return "removed from the room";
+    case livekit::DisconnectReason::RoomDeleted: return "the room was deleted";
+    case livekit::DisconnectReason::StateMismatch: return "session could not be resumed";
+    case livekit::DisconnectReason::JoinFailure: return "could not join the room (token rejected or expired?)";
+    case livekit::DisconnectReason::Migration: return "migrating to another server";
+    case livekit::DisconnectReason::SignalClose: return "the signalling connection closed";
+    case livekit::DisconnectReason::RoomClosed: return "the room closed";
+    case livekit::DisconnectReason::UserUnavailable: return "user unavailable";
+    case livekit::DisconnectReason::UserRejected: return "connection rejected";
+    case livekit::DisconnectReason::SipTrunkFailure: return "SIP trunk failure";
+    case livekit::DisconnectReason::ConnectionTimeout: return "connection timed out";
+    case livekit::DisconnectReason::MediaFailure: return "media connection failed";
+    case livekit::DisconnectReason::AgentError: return "agent error";
+    }
+    return "disconnected";
+}
+
+// --- Process-wide SDK lifetime ---------------------------------------------
+
+std::mutex &globalMutex()
+{
+    static std::mutex m;
+    return m;
+}
+
+int &globalRefCount()
+{
+    static int n = 0;
+    return n;
+}
+
+} // namespace
+
+// ---------------------------------------------------------------------------
+// Impl
+// ---------------------------------------------------------------------------
+
+struct LiveKitSession::Impl : public livekit::RoomDelegate {
+    enum class CommandType { AttachVideo, DetachVideo, AttachAudio, DetachAudio, Stop };
+
+    struct Command {
+        CommandType type;
+        std::shared_ptr<livekit::Track> track;
+    };
+
+    livekit::Room room;
+    SessionConfig config;
+
+    mutable std::mutex state_mutex;
+    SessionStateMachine machine;
+
+    VideoFrameHandler on_video;
+    AudioFrameHandler on_audio;
+    SessionStateHandler on_state;
+
+    std::atomic<std::uint64_t> video_frames{0};
+    std::atomic<std::uint64_t> audio_frames{0};
+    std::atomic<std::uint64_t> dropped_frames{0};
+
+    // Command queue. Every interaction with livekit::VideoStream /
+    // livekit::AudioStream happens on `worker`, never on a room event thread:
+    // the SDK's room callbacks run on its own event thread and blocking or
+    // re-entering there stalls every other event (and Room::disconnect() from
+    // inside one is documented to deadlock outright).
+    std::mutex queue_mutex;
+    std::condition_variable queue_cv;
+    std::deque<Command> queue;
+    std::thread worker;
+    bool worker_running = false;
+
+    // Owned exclusively by the worker thread.
+    std::shared_ptr<livekit::VideoStream> video_stream;
+    std::thread video_thread;
+    std::shared_ptr<livekit::AudioStream> audio_stream;
+    std::thread audio_thread;
+
+    bool connected = false;
+
+    ~Impl() override = default;
+
+    // --- state helpers -----------------------------------------------------
+
+    template<typename Fn> void mutateState(Fn &&fn)
+    {
+        SessionState state;
+        std::string detail;
+        SessionStateHandler handler;
+        {
+            std::lock_guard<std::mutex> guard(state_mutex);
+            fn(machine);
+            state = machine.state();
+            detail = machine.detail();
+            handler = on_state;
+        }
+        // Notified outside the lock: the handler is OBS adapter code and must
+        // never be able to deadlock against a concurrent state query.
+        if (handler)
+            handler(state, detail);
+    }
+
+    void post(CommandType type, std::shared_ptr<livekit::Track> track = nullptr)
+    {
+        {
+            std::lock_guard<std::mutex> guard(queue_mutex);
+            if (!worker_running)
+                return;
+            queue.push_back(Command{type, std::move(track)});
+        }
+        queue_cv.notify_one();
+    }
+
+    // --- RoomDelegate ------------------------------------------------------
+
+    void onTrackSubscribed(livekit::Room &, const livekit::TrackSubscribedEvent &event) override
+    {
+        if (!event.participant || !event.track)
+            return;
+        const std::string identity = event.participant->identity();
+        const MediaKind kind = toMediaKind(event.track->kind());
+        const MediaSource source =
+            event.publication ? toMediaSource(event.publication->source()) : MediaSource::Unknown;
+
+        if (isWantedVideoTrack(config.participant_identity, identity, kind, source))
+            post(CommandType::AttachVideo, event.track);
+        else if (config.subscribe_audio && isWantedAudioTrack(config.participant_identity, identity, kind, source))
+            post(CommandType::AttachAudio, event.track);
+    }
+
+    void onTrackUnsubscribed(livekit::Room &, const livekit::TrackUnsubscribedEvent &event) override
+    {
+        if (!event.participant || !event.track)
+            return;
+        if (event.participant->identity() != config.participant_identity)
+            return;
+        const MediaKind kind = toMediaKind(event.track->kind());
+        if (kind == MediaKind::Video)
+            post(CommandType::DetachVideo);
+        else if (kind == MediaKind::Audio)
+            post(CommandType::DetachAudio);
+    }
+
+    void onParticipantDisconnected(livekit::Room &, const livekit::ParticipantDisconnectedEvent &event) override
+    {
+        if (!event.participant || event.participant->identity() != config.participant_identity)
+            return;
+        // The slot went away entirely. This is the placeholder state, not an
+        // error: the operator's room is fine, the camera just left.
+        post(CommandType::DetachVideo);
+        post(CommandType::DetachAudio);
+    }
+
+    void onReconnecting(livekit::Room &, const livekit::ReconnectingEvent &) override
+    {
+        mutateState([](SessionStateMachine &m) { m.onReconnecting(); });
+    }
+
+    void onReconnected(livekit::Room &, const livekit::ReconnectedEvent &) override
+    {
+        mutateState([](SessionStateMachine &m) { m.onReconnected(); });
+    }
+
+    void onDisconnected(livekit::Room &, const livekit::DisconnectedEvent &event) override
+    {
+        const std::string reason = describeDisconnectReason(event.reason);
+        const bool fatal = isFatalDisconnect(event.reason);
+        post(CommandType::DetachVideo);
+        post(CommandType::DetachAudio);
+        mutateState([&](SessionStateMachine &m) { m.onRoomEnded(reason, fatal); });
+    }
+
+    void onRoomEos(livekit::Room &, const livekit::RoomEosEvent &) override
+    {
+        post(CommandType::DetachVideo);
+        post(CommandType::DetachAudio);
+        mutateState([](SessionStateMachine &m) { m.onRoomEnded("the room session ended", false); });
+    }
+
+    // --- worker ------------------------------------------------------------
+
+    void startWorker()
+    {
+        {
+            std::lock_guard<std::mutex> guard(queue_mutex);
+            queue.clear();
+            worker_running = true;
+        }
+        worker = std::thread([this] { workerLoop(); });
+    }
+
+    void stopWorker()
+    {
+        {
+            std::lock_guard<std::mutex> guard(queue_mutex);
+            if (!worker_running)
+                return;
+            queue.push_back(Command{CommandType::Stop, nullptr});
+            worker_running = false;
+        }
+        queue_cv.notify_one();
+        if (worker.joinable())
+            worker.join();
+    }
+
+    void workerLoop()
+    {
+        for (;;) {
+            Command command{CommandType::Stop, nullptr};
+            {
+                std::unique_lock<std::mutex> lock(queue_mutex);
+                queue_cv.wait(lock, [this] { return !queue.empty(); });
+                command = std::move(queue.front());
+                queue.pop_front();
+            }
+
+            switch (command.type) {
+            case CommandType::AttachVideo:
+                attachVideo(command.track);
+                break;
+            case CommandType::DetachVideo:
+                detachVideo();
+                break;
+            case CommandType::AttachAudio:
+                attachAudio(command.track);
+                break;
+            case CommandType::DetachAudio:
+                detachAudio();
+                break;
+            case CommandType::Stop:
+                detachVideo();
+                detachAudio();
+                return;
+            }
+        }
+    }
+
+    void attachVideo(const std::shared_ptr<livekit::Track> &track)
+    {
+        if (!track)
+            return;
+        // Replacing an existing stream is the publisher-swap path: tear the
+        // old reader all the way down first so no frame from the previous
+        // publisher can arrive after the new one starts.
+        detachVideo();
+
+        livekit::VideoStream::Options options;
+        options.capacity = config.video_queue_capacity;
+        options.format = toLiveKitBufferType(config.video_format);
+
+        std::shared_ptr<livekit::VideoStream> stream;
+        try {
+            stream = livekit::VideoStream::fromTrack(track, options);
+        } catch (const std::exception &e) {
+            mutateState([&](SessionStateMachine &m) {
+                m.onRoomEnded(std::string("could not open the video stream: ") + e.what(), true);
+            });
+            return;
+        }
+        if (!stream)
+            return;
+
+        video_stream = stream;
+        video_thread = std::thread([this, stream] { videoReaderLoop(stream); });
+        mutateState([](SessionStateMachine &m) { m.onVideoAttached(); });
+    }
+
+    void detachVideo()
+    {
+        if (video_stream)
+            video_stream->close(); // wakes the blocking read()
+        if (video_thread.joinable())
+            video_thread.join();
+        const bool had = static_cast<bool>(video_stream);
+        video_stream.reset();
+        if (had)
+            mutateState([](SessionStateMachine &m) { m.onVideoDetached(); });
+    }
+
+    void attachAudio(const std::shared_ptr<livekit::Track> &track)
+    {
+        if (!track)
+            return;
+        detachAudio();
+
+        livekit::AudioStream::Options options;
+        options.capacity = config.audio_queue_capacity;
+
+        std::shared_ptr<livekit::AudioStream> stream;
+        try {
+            stream = livekit::AudioStream::fromTrack(track, options);
+        } catch (const std::exception &) {
+            // Audio is not worth failing the whole source over: a camera with
+            // no usable audio track is still a usable camera.
+            return;
+        }
+        if (!stream)
+            return;
+
+        audio_stream = stream;
+        audio_thread = std::thread([this, stream] { audioReaderLoop(stream); });
+        mutateState([](SessionStateMachine &m) { m.onAudioAttached(); });
+    }
+
+    void detachAudio()
+    {
+        if (audio_stream)
+            audio_stream->close();
+        if (audio_thread.joinable())
+            audio_thread.join();
+        const bool had = static_cast<bool>(audio_stream);
+        audio_stream.reset();
+        if (had)
+            mutateState([](SessionStateMachine &m) { m.onAudioDetached(); });
+    }
+
+    void videoReaderLoop(std::shared_ptr<livekit::VideoStream> stream)
+    {
+        VideoFrameHandler handler;
+        {
+            std::lock_guard<std::mutex> guard(state_mutex);
+            handler = on_video;
+        }
+
+        livekit::VideoFrameEvent event;
+        while (stream->read(event)) {
+            if (!handler)
+                continue;
+            deliverVideoFrame(event, handler);
+        }
+    }
+
+    void deliverVideoFrame(livekit::VideoFrameEvent &event, const VideoFrameHandler &handler)
+    {
+        PixelFormat format;
+        const livekit::VideoFrame *frame = &event.frame;
+        livekit::VideoFrame converted;
+
+        if (!fromLiveKitBufferType(frame->type(), format)) {
+            // The SDK gave us something the adapter cannot hand to OBS.
+            // convert() is a full CPU repack, so this is a fallback, not the
+            // normal path -- the normal path is the format we asked for.
+            try {
+                converted = frame->convert(toLiveKitBufferType(config.video_format));
+            } catch (const std::exception &) {
+                dropped_frames.fetch_add(1);
+                return;
+            }
+            frame = &converted;
+            format = config.video_format;
+        }
+
+        const int width = frame->width();
+        const int height = frame->height();
+        const std::size_t expected = expectedFrameBytes(format, width, height);
+        if (expected == 0 || frame->dataSize() < expected) {
+            // Geometry that does not match the buffer would make OBS read off
+            // the end of it. Drop rather than trust.
+            dropped_frames.fetch_add(1);
+            return;
+        }
+
+        VideoFrameData out;
+        out.width = width;
+        out.height = height;
+        out.format = format;
+        out.data = frame->data();
+        out.size = frame->dataSize();
+        out.timestamp_us = event.timestamp_us;
+
+        const std::vector<livekit::VideoPlaneInfo> planes = frame->planeInfos();
+        const int wanted_planes = planeCount(format);
+        int count = 0;
+        for (const livekit::VideoPlaneInfo &plane : planes) {
+            if (count >= 4)
+                break;
+            out.planes[count].data = reinterpret_cast<const std::uint8_t *>(plane.data_ptr);
+            out.planes[count].stride = plane.stride;
+            out.planes[count].size = plane.size;
+            ++count;
+        }
+        if (count == 0 && wanted_planes == 1) {
+            // planeInfos() documents that packed formats may return an empty
+            // list rather than one plane. Synthesise it from the frame buffer
+            // instead of dropping a perfectly good BGRA frame.
+            out.planes[0].data = frame->data();
+            out.planes[0].stride = static_cast<std::uint32_t>(width) * 4u;
+            out.planes[0].size = static_cast<std::uint32_t>(frame->dataSize());
+            count = 1;
+        }
+        if (count != wanted_planes) {
+            dropped_frames.fetch_add(1);
+            return;
+        }
+        out.plane_count = count;
+
+        video_frames.fetch_add(1);
+        handler(out);
+    }
+
+    void audioReaderLoop(std::shared_ptr<livekit::AudioStream> stream)
+    {
+        AudioFrameHandler handler;
+        {
+            std::lock_guard<std::mutex> guard(state_mutex);
+            handler = on_audio;
+        }
+
+        livekit::AudioFrameEvent event;
+        while (stream->read(event)) {
+            if (!handler)
+                continue;
+            const livekit::AudioFrame &frame = event.frame;
+            if (frame.numChannels() <= 0 || frame.samplesPerChannel() <= 0 || frame.sampleRate() <= 0)
+                continue;
+            AudioFrameData out;
+            out.samples = frame.data().data();
+            out.sample_count = frame.totalSamples();
+            out.sample_rate = frame.sampleRate();
+            out.channels = frame.numChannels();
+            out.samples_per_channel = frame.samplesPerChannel();
+            audio_frames.fetch_add(1);
+            handler(out);
+        }
+    }
+
+    /// After connect(), the target slot may already be in the room with its
+    /// tracks subscribed, in which case no onTrackSubscribed event is coming.
+    /// Sweep what is already there so a source added mid-show shows video
+    /// immediately instead of waiting for the publisher to republish.
+    void attachExistingTracks()
+    {
+        auto participant = room.remoteParticipant(config.participant_identity).lock();
+        if (!participant)
+            return;
+        const std::string identity = participant->identity();
+        for (const auto &entry : participant->trackPublications()) {
+            const std::shared_ptr<livekit::RemoteTrackPublication> &publication = entry.second;
+            if (!publication)
+                continue;
+            const std::shared_ptr<livekit::Track> track = publication->track();
+            if (!track)
+                continue; // published but not subscribed yet
+            const MediaKind kind = toMediaKind(track->kind());
+            const MediaSource source = toMediaSource(publication->source());
+            if (isWantedVideoTrack(config.participant_identity, identity, kind, source))
+                post(CommandType::AttachVideo, track);
+            else if (config.subscribe_audio && isWantedAudioTrack(config.participant_identity, identity, kind, source))
+                post(CommandType::AttachAudio, track);
+        }
+    }
+};
+
+// ---------------------------------------------------------------------------
+// LiveKitSession
+// ---------------------------------------------------------------------------
+
+LiveKitSession::LiveKitSession() : impl_(new Impl()) {}
+
+LiveKitSession::~LiveKitSession()
+{
+    disconnect();
+}
+
+void LiveKitSession::setVideoHandler(VideoFrameHandler handler)
+{
+    std::lock_guard<std::mutex> guard(impl_->state_mutex);
+    impl_->on_video = std::move(handler);
+}
+
+void LiveKitSession::setAudioHandler(AudioFrameHandler handler)
+{
+    std::lock_guard<std::mutex> guard(impl_->state_mutex);
+    impl_->on_audio = std::move(handler);
+}
+
+void LiveKitSession::setStateHandler(SessionStateHandler handler)
+{
+    std::lock_guard<std::mutex> guard(impl_->state_mutex);
+    impl_->on_state = std::move(handler);
+}
+
+bool LiveKitSession::connect(const SessionConfig &config)
+{
+    if (impl_->connected)
+        disconnect();
+
+    impl_->config = config;
+    impl_->video_frames.store(0);
+    impl_->audio_frames.store(0);
+    impl_->dropped_frames.store(0);
+
+    impl_->mutateState([](SessionStateMachine &m) { m.onConnectRequested(); });
+
+    if (config.ws_url.empty() || config.token.empty() || config.participant_identity.empty()) {
+        impl_->mutateState(
+            [](SessionStateMachine &m) { m.onConnectFailed("missing LiveKit URL, token or camera selection"); });
+        return false;
+    }
+
+    impl_->startWorker();
+
+    livekit::RoomOptions options;
+    // auto_subscribe is what makes track_subscribed events (and therefore any
+    // media at all) happen; the SDK is emphatic about this.
+    //
+    // Known, measured-but-unaddressed cost: auto_subscribe pulls every
+    // participant's published track, not just the one camera this session
+    // actually wants, and this client discards the unwanted ones
+    // client-side. In a multi-camera room that is real, wasted bandwidth
+    // and decode CPU that scales with room size, not with what this source
+    // displays. Selectively unsubscribing from unwanted publications (the
+    // SDK exposes per-publication subscribe/unsubscribe) is a real
+    // follow-up optimization, deliberately out of scope here.
+    options.auto_subscribe = true;
+    options.dynacast = false;
+    // This client never publishes, so a single peer connection is all it
+    // needs.
+    options.single_peer_connection = true;
+    options.connect_timeout = std::chrono::milliseconds(config.connect_timeout_ms);
+
+    impl_->room.setDelegate(impl_.get());
+
+    bool ok = false;
+    try {
+        ok = impl_->room.connect(config.ws_url, config.token, options);
+    } catch (const std::exception &e) {
+        ok = false;
+        impl_->mutateState([&](SessionStateMachine &m) { m.onConnectFailed(e.what()); });
+        impl_->stopWorker();
+        impl_->room.setDelegate(nullptr);
+        return false;
+    }
+
+    if (!ok) {
+        impl_->mutateState([](SessionStateMachine &m) {
+            m.onConnectFailed("could not connect to LiveKit (check the server URL, or the token may have expired)");
+        });
+        impl_->stopWorker();
+        impl_->room.setDelegate(nullptr);
+        return false;
+    }
+
+    impl_->connected = true;
+    impl_->mutateState([](SessionStateMachine &m) { m.onConnectSucceeded(); });
+    impl_->attachExistingTracks();
+    return true;
+}
+
+void LiveKitSession::disconnect()
+{
+    if (!impl_)
+        return;
+
+    // Order matters: stop the readers first so nothing is mid-read on a
+    // stream the room is about to tear down, then disconnect the room, then
+    // drop the delegate so no event can arrive at a half-destroyed object.
+    impl_->stopWorker();
+
+    if (impl_->connected) {
+        impl_->connected = false;
+        try {
+            impl_->room.disconnect(livekit::DisconnectReason::ClientInitiated);
+        } catch (const std::exception &) {
+            // Best effort: a failed graceful disconnect must not stop the
+            // OBS source from being destroyed.
+        }
+        impl_->mutateState([](SessionStateMachine &m) { m.onLocalDisconnect(); });
+    }
+
+    impl_->room.setDelegate(nullptr);
+}
+
+SessionState LiveKitSession::state() const
+{
+    std::lock_guard<std::mutex> guard(impl_->state_mutex);
+    return impl_->machine.state();
+}
+
+std::string LiveKitSession::stateDetail() const
+{
+    std::lock_guard<std::mutex> guard(impl_->state_mutex);
+    return impl_->machine.detail();
+}
+
+bool LiveKitSession::hasVideo() const
+{
+    std::lock_guard<std::mutex> guard(impl_->state_mutex);
+    return impl_->machine.hasVideo();
+}
+
+bool LiveKitSession::hasAudio() const
+{
+    std::lock_guard<std::mutex> guard(impl_->state_mutex);
+    return impl_->machine.hasAudio();
+}
+
+bool LiveKitSession::waitingForCamera() const
+{
+    std::lock_guard<std::mutex> guard(impl_->state_mutex);
+    return impl_->machine.waitingForCamera();
+}
+
+std::uint64_t LiveKitSession::videoFrameCount() const
+{
+    return impl_->video_frames.load();
+}
+
+std::uint64_t LiveKitSession::audioFrameCount() const
+{
+    return impl_->audio_frames.load();
+}
+
+void LiveKitSession::globalInitialize()
+{
+    std::lock_guard<std::mutex> guard(globalMutex());
+    if (globalRefCount()++ == 0)
+        livekit::initialize(livekit::LogLevel::Warn);
+}
+
+void LiveKitSession::globalShutdown()
+{
+    std::lock_guard<std::mutex> guard(globalMutex());
+    if (globalRefCount() > 0 && --globalRefCount() == 0)
+        livekit::shutdown();
+}
+
+} // namespace stplugin

core/src/session_types.cpp

@@ -0,0 +1,185 @@
+/*
+streamer-tools OBS Camera Plugin - session types and pure session logic
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#include "stplugin/session_types.h"
+
+namespace stplugin {
+
+const char *describePixelFormat(PixelFormat format)
+{
+    switch (format) {
+    case PixelFormat::I420: return "I420";
+    case PixelFormat::NV12: return "NV12";
+    case PixelFormat::BGRA: return "BGRA";
+    }
+    return "unknown";
+}
+
+int planeCount(PixelFormat format)
+{
+    switch (format) {
+    case PixelFormat::I420: return 3;
+    case PixelFormat::NV12: return 2;
+    case PixelFormat::BGRA: return 1;
+    }
+    return 0;
+}
+
+std::size_t expectedFrameBytes(PixelFormat format, int width, int height)
+{
+    if (width <= 0 || height <= 0)
+        return 0;
+    const std::size_t w = static_cast<std::size_t>(width);
+    const std::size_t h = static_cast<std::size_t>(height);
+    // Chroma planes round up, which is what libyuv/WebRTC do for odd sizes.
+    const std::size_t cw = (w + 1) / 2;
+    const std::size_t ch = (h + 1) / 2;
+    switch (format) {
+    case PixelFormat::I420: return w * h + 2 * cw * ch;
+    case PixelFormat::NV12: return w * h + 2 * cw * ch;
+    case PixelFormat::BGRA: return w * h * 4;
+    }
+    return 0;
+}
+
+bool isWantedVideoTrack(const std::string &wanted_identity, const std::string &track_identity, MediaKind kind,
+                        MediaSource source)
+{
+    if (wanted_identity.empty() || track_identity != wanted_identity)
+        return false;
+    if (kind != MediaKind::Video)
+        return false;
+    return source == MediaSource::Camera || source == MediaSource::Unknown;
+}
+
+bool isWantedAudioTrack(const std::string &wanted_identity, const std::string &track_identity, MediaKind kind,
+                        MediaSource source)
+{
+    if (wanted_identity.empty() || track_identity != wanted_identity)
+        return false;
+    if (kind != MediaKind::Audio)
+        return false;
+    return source == MediaSource::Microphone || source == MediaSource::Unknown;
+}
+
+const char *describeSessionState(SessionState state)
+{
+    switch (state) {
+    case SessionState::Idle: return "idle";
+    case SessionState::Connecting: return "connecting";
+    case SessionState::Connected: return "connected";
+    case SessionState::Reconnecting: return "reconnecting";
+    case SessionState::Disconnected: return "disconnected";
+    case SessionState::Failed: return "failed";
+    }
+    return "unknown";
+}
+
+bool SessionStateMachine::waitingForCamera() const
+{
+    return (state_ == SessionState::Connected || state_ == SessionState::Reconnecting) && !has_video_;
+}
+
+void SessionStateMachine::onConnectRequested()
+{
+    state_ = SessionState::Connecting;
+    // A new attempt clears the previous failure reason, so a stale message
+    // can never be shown alongside a fresh, healthy connection.
+    detail_.clear();
+    has_video_ = false;
+    has_audio_ = false;
+}
+
+void SessionStateMachine::onConnectSucceeded()
+{
+    state_ = SessionState::Connected;
+    detail_.clear();
+}
+
+void SessionStateMachine::onConnectFailed(const std::string &reason)
+{
+    state_ = SessionState::Failed;
+    detail_ = reason;
+    has_video_ = false;
+    has_audio_ = false;
+}
+
+void SessionStateMachine::onReconnecting()
+{
+    // Only meaningful from a live session; a reconnect notification after we
+    // already gave up must not resurrect the session.
+    if (state_ != SessionState::Connected && state_ != SessionState::Reconnecting)
+        return;
+    state_ = SessionState::Reconnecting;
+    detail_ = "reconnecting";
+    // Tracks are re-subscribed on the other side of a reconnect; the SDK will
+    // tell us when they are back.
+    has_video_ = false;
+    has_audio_ = false;
+}
+
+void SessionStateMachine::onReconnected()
+{
+    if (state_ != SessionState::Reconnecting)
+        return;
+    state_ = SessionState::Connected;
+    detail_.clear();
+}
+
+void SessionStateMachine::onRoomEnded(const std::string &reason, bool fatal)
+{
+    if (state_ == SessionState::Idle || state_ == SessionState::Disconnected)
+        return;
+    state_ = fatal ? SessionState::Failed : SessionState::Disconnected;
+    detail_ = reason;
+    has_video_ = false;
+    has_audio_ = false;
+}
+
+void SessionStateMachine::onLocalDisconnect()
+{
+    state_ = SessionState::Disconnected;
+    detail_.clear();
+    has_video_ = false;
+    has_audio_ = false;
+}
+
+void SessionStateMachine::onVideoAttached()
+{
+    has_video_ = true;
+}
+
+void SessionStateMachine::onVideoDetached()
+{
+    // A publisher swap (the motivating bug) shows up here: the old track goes
+    // away and a new one arrives moments later. That is a placeholder state,
+    // never an error state -- the connection itself is untouched.
+    has_video_ = false;
+}
+
+void SessionStateMachine::onAudioAttached()
+{
+    has_audio_ = true;
+}
+
+void SessionStateMachine::onAudioDetached()
+{
+    has_audio_ = false;
+}
+
+} // namespace stplugin

core/tests/CMakeLists.txt

@@ -1,7 +1,39 @@
-add_executable(stplugin_core_tests
+# Dependency-free CTest targets (see test_util.h for why there is no gtest).
-    test_core.cpp
+
+function(stplugin_add_test name)
+    add_executable(${name} ${name}.cpp)
+    target_link_libraries(${name} PRIVATE stplugin_core)
+    target_include_directories(${name} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+    if(WIN32)
+        # loopback_server.h needs Winsock for the real-backend tests.
+        target_link_libraries(${name} PRIVATE ws2_32)
+    endif()
+    add_test(NAME ${name} COMMAND ${name})
+    # Nothing here should ever take a minute; a hang is a failure, not a
+    # reason for CI to sit for its default 1500s.
+    set_tests_properties(${name} PROPERTIES TIMEOUT 120)
+endfunction()
+
+stplugin_add_test(test_core)
+target_compile_definitions(test_core PRIVATE
+    STPLUGIN_EXPECTED_CORE_VERSION="${PROJECT_VERSION}"
 )
+stplugin_add_test(test_json)
+stplugin_add_test(test_api_client)
+stplugin_add_test(test_session)
 
-target_link_libraries(stplugin_core_tests PRIVATE stplugin_core)
+# End-to-end against a REAL LiveKit room: publishes a synthetic camera with
+# the same SDK and subscribes to it through LiveKitSession. Skips (exit 0)
+# unless STPLUGIN_IT_* is set, so the three build runners -- which have no
+# LiveKit server -- stay green. See scripts/livekit-dev-room.py.
+stplugin_add_test(test_integration_livekit)
+set_tests_properties(test_integration_livekit PROPERTIES TIMEOUT 300)
 
-add_test(NAME stplugin_core_tests COMMAND stplugin_core_tests)
+# Smoke test for the LiveKit SDK link: initialize()/shutdown() must succeed
+# in-process. This is the cheapest possible proof that LiveKit::livekit is
+# not just linked but loadable and callable (it dlopen-chains into
+# liblivekit_ffi, which is where a broken RPATH would show up).
+stplugin_add_test(test_livekit_smoke)
+target_compile_definitions(test_livekit_smoke PRIVATE
+    STPLUGIN_EXPECTED_LIVEKIT_VERSION="${LIVEKIT_SDK_VERSION_RESOLVED}"
+)

core/tests/loopback_server.h

@@ -0,0 +1,246 @@
+/*
+streamer-tools OBS Camera Plugin - minimal loopback HTTP server for tests
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#pragma once
+
+// A single-threaded, one-request-at-a-time HTTP/1.1 server on 127.0.0.1, used
+// to exercise the *real* platform HTTP backend (libcurl on Linux/macOS,
+// WinHTTP on Windows) rather than only a fake. The handler returns raw bytes,
+// so tests can serve deliberately malformed responses and half-closed
+// connections -- the cases that must not hang or crash OBS.
+//
+// Plain HTTP only: a TLS listener would need a certificate and would test
+// libcurl/SChannel rather than this plugin.
+
+#include <atomic>
+#include <cstdlib>
+#include <cstring>
+#include <functional>
+#include <mutex>
+#include <string>
+#include <thread>
+
+#ifdef _WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+using st_socket_t = SOCKET;
+#define ST_INVALID_SOCKET INVALID_SOCKET
+#define ST_CLOSE_SOCKET closesocket
+#else
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <unistd.h>
+using st_socket_t = int;
+#define ST_INVALID_SOCKET (-1)
+#define ST_CLOSE_SOCKET ::close
+#endif
+
+namespace sttest {
+
+/// Returns raw response bytes for a received raw request. Returning an empty
+/// string means "close the connection without replying".
+using LoopbackHandler = std::function<std::string(const std::string &request)>;
+
+class LoopbackServer {
+public:
+    explicit LoopbackServer(LoopbackHandler handler) : handler_(std::move(handler))
+    {
+#ifdef _WIN32
+        WSADATA wsa;
+        WSAStartup(MAKEWORD(2, 2), &wsa);
+#endif
+        listen_ = ::socket(AF_INET, SOCK_STREAM, 0);
+        if (listen_ == ST_INVALID_SOCKET)
+            return;
+
+        int reuse = 1;
+        ::setsockopt(listen_, SOL_SOCKET, SO_REUSEADDR, reinterpret_cast<const char *>(&reuse), sizeof(reuse));
+
+        sockaddr_in addr{};
+        addr.sin_family = AF_INET;
+        addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+        addr.sin_port = 0; // let the OS pick a free port
+        if (::bind(listen_, reinterpret_cast<sockaddr *>(&addr), sizeof(addr)) != 0) {
+            ST_CLOSE_SOCKET(listen_);
+            listen_ = ST_INVALID_SOCKET;
+            return;
+        }
+        if (::listen(listen_, 4) != 0) {
+            ST_CLOSE_SOCKET(listen_);
+            listen_ = ST_INVALID_SOCKET;
+            return;
+        }
+
+        sockaddr_in bound{};
+#ifdef _WIN32
+        int len = sizeof(bound);
+#else
+        socklen_t len = sizeof(bound);
+#endif
+        if (::getsockname(listen_, reinterpret_cast<sockaddr *>(&bound), &len) != 0) {
+            ST_CLOSE_SOCKET(listen_);
+            listen_ = ST_INVALID_SOCKET;
+            return;
+        }
+        port_ = ntohs(bound.sin_port);
+
+        thread_ = std::thread([this] { run(); });
+    }
+
+    ~LoopbackServer()
+    {
+        stop_.store(true);
+        if (thread_.joinable())
+            thread_.join();
+        if (listen_ != ST_INVALID_SOCKET)
+            ST_CLOSE_SOCKET(listen_);
+#ifdef _WIN32
+        WSACleanup();
+#endif
+    }
+
+    LoopbackServer(const LoopbackServer &) = delete;
+    LoopbackServer &operator=(const LoopbackServer &) = delete;
+
+    bool valid() const { return listen_ != ST_INVALID_SOCKET; }
+    int port() const { return port_; }
+    std::string baseUrl() const { return "http://127.0.0.1:" + std::to_string(port_); }
+    int requestCount() const { return requests_.load(); }
+
+    /// The most recent raw request, for asserting on method/path/body.
+    std::string lastRequest() const
+    {
+        std::lock_guard<std::mutex> guard(mutex_);
+        return last_request_;
+    }
+
+private:
+    void run()
+    {
+        while (!stop_.load()) {
+            // select() with a short timeout rather than a blocking accept(),
+            // so the destructor's stop flag is honoured promptly on every
+            // platform (closing a socket another thread is blocked in
+            // accept() on is not portable).
+            fd_set readable;
+            FD_ZERO(&readable);
+            FD_SET(listen_, &readable);
+            timeval tv{};
+            tv.tv_sec = 0;
+            tv.tv_usec = 50000; // 50ms
+            const int ready = ::select(static_cast<int>(listen_) + 1, &readable, nullptr, nullptr, &tv);
+            if (ready <= 0)
+                continue;
+
+            st_socket_t client = ::accept(listen_, nullptr, nullptr);
+            if (client == ST_INVALID_SOCKET)
+                continue;
+
+            const std::string request = readRequest(client);
+            {
+                std::lock_guard<std::mutex> guard(mutex_);
+                last_request_ = request;
+            }
+            requests_.fetch_add(1);
+
+            const std::string response = handler_ ? handler_(request) : std::string();
+            if (!response.empty())
+                sendAll(client, response);
+            ST_CLOSE_SOCKET(client);
+        }
+    }
+
+    static std::string readRequest(st_socket_t client)
+    {
+        std::string data;
+        char buffer[4096];
+        std::size_t header_end = std::string::npos;
+        long content_length = 0;
+
+        for (;;) {
+#ifdef _WIN32
+            const int n = ::recv(client, buffer, static_cast<int>(sizeof(buffer)), 0);
+#else
+            const ssize_t n = ::recv(client, buffer, sizeof(buffer), 0);
+#endif
+            if (n <= 0)
+                break;
+            data.append(buffer, static_cast<std::size_t>(n));
+
+            if (header_end == std::string::npos) {
+                header_end = data.find("\r\n\r\n");
+                if (header_end != std::string::npos)
+                    content_length = parseContentLength(data.substr(0, header_end));
+            }
+            if (header_end != std::string::npos &&
+                data.size() >= header_end + 4 + static_cast<std::size_t>(content_length))
+                break;
+        }
+        return data;
+    }
+
+    static long parseContentLength(const std::string &headers)
+    {
+        std::string lower;
+        lower.reserve(headers.size());
+        for (char c : headers)
+            lower.push_back(static_cast<char>(c >= 'A' && c <= 'Z' ? c + 32 : c));
+        const std::size_t at = lower.find("content-length:");
+        if (at == std::string::npos)
+            return 0;
+        return std::strtol(headers.c_str() + at + 15, nullptr, 10);
+    }
+
+    static void sendAll(st_socket_t client, const std::string &data)
+    {
+        std::size_t sent = 0;
+        while (sent < data.size()) {
+#ifdef _WIN32
+            const int n = ::send(client, data.data() + sent, static_cast<int>(data.size() - sent), 0);
+#else
+            const ssize_t n = ::send(client, data.data() + sent, data.size() - sent, 0);
+#endif
+            if (n <= 0)
+                return;
+            sent += static_cast<std::size_t>(n);
+        }
+    }
+
+    LoopbackHandler handler_;
+    st_socket_t listen_ = ST_INVALID_SOCKET;
+    int port_ = 0;
+    std::thread thread_;
+    std::atomic<bool> stop_{false};
+    std::atomic<int> requests_{0};
+    mutable std::mutex mutex_;
+    std::string last_request_;
+};
+
+/// Build a well-formed HTTP/1.1 response with an explicit Content-Length and
+/// Connection: close, so the client never waits for keep-alive reuse.
+inline std::string httpResponse(int status, const std::string &reason, const std::string &body,
+                                const std::string &content_type = "application/json")
+{
+    return "HTTP/1.1 " + std::to_string(status) + " " + reason + "\r\n" + "Content-Type: " + content_type +
+           "\r\n" + "Content-Length: " + std::to_string(body.size()) + "\r\n" + "Connection: close\r\n\r\n" +
+           body;
+}
+
+} // namespace sttest

core/tests/test_api_client.cpp

@@ -0,0 +1,467 @@
+/*
+streamer-tools OBS Camera Plugin - API client tests
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+// Two layers of coverage:
+//   1. a fake HttpClient, for response parsing and every error branch;
+//   2. a real loopback HTTP server driven through the *platform* backend
+//      (libcurl or WinHTTP), so the backend itself is exercised in CI on all
+//      three runners rather than assumed to work.
+
+#include <chrono>
+#include <memory>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include "stplugin/api_client.h"
+#include "stplugin/http.h"
+
+#include "loopback_server.h"
+#include "test_util.h"
+
+using namespace stplugin;
+
+namespace {
+
+class FakeHttpClient : public HttpClient {
+public:
+    HttpResponse next;
+    HttpRequest last;
+    int calls = 0;
+
+    HttpResponse send(const HttpRequest &request) override
+    {
+        last = request;
+        ++calls;
+        return next;
+    }
+};
+
+ConnectionConfig testConfig()
+{
+    return ConnectionConfig{"https://streamers.example.com", "main-room", "readkey123"};
+}
+
+std::shared_ptr<FakeHttpClient> makeFake(long status, const std::string &body)
+{
+    auto fake = std::make_shared<FakeHttpClient>();
+    fake->next.status = status;
+    fake->next.body = body;
+    return fake;
+}
+
+// ---------------------------------------------------------------------------
+// URL handling
+// ---------------------------------------------------------------------------
+
+void testNormalizeServerUrl()
+{
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("https://a.example.com"), std::string("https://a.example.com"));
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("https://a.example.com/"), std::string("https://a.example.com"));
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("https://a.example.com///"), std::string("https://a.example.com"));
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("  https://a.example.com  "), std::string("https://a.example.com"));
+    // No scheme defaults to https, never http: the read key is a credential.
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("a.example.com"), std::string("https://a.example.com"));
+    // An explicit http:// is honoured -- the test LXC is reachable that way.
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("http://192.168.1.175:3000"), std::string("http://192.168.1.175:3000"));
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl(""), std::string(""));
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("   "), std::string(""));
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("https://"), std::string(""));
+    ST_ASSERT_EQ(ApiClient::normalizeServerUrl("/"), std::string(""));
+}
+
+void testUrlEncodeAndRedaction()
+{
+    ST_ASSERT_EQ(urlEncode("plain-slug_1.0~"), std::string("plain-slug_1.0~"));
+    ST_ASSERT_EQ(urlEncode("a b"), std::string("a%20b"));
+    ST_ASSERT_EQ(urlEncode("a/b?c=d&e"), std::string("a%2Fb%3Fc%3Dd%26e"));
+    ST_ASSERT_EQ(urlEncode("k\xc3\xa9y"), std::string("k%C3%A9y"));
+
+    ST_ASSERT_EQ(ApiClient::redactedUrl("https://h/api/obs/r/slots?key=secret"),
+                 std::string("https://h/api/obs/r/slots?key=***"));
+    ST_ASSERT_EQ(ApiClient::redactedUrl("https://h/api/obs/r/slots?key=secret&x=1"),
+                 std::string("https://h/api/obs/r/slots?key=***&x=1"));
+    ST_ASSERT_EQ(ApiClient::redactedUrl("https://h/nothing"), std::string("https://h/nothing"));
+}
+
+void testRedactSensitiveParams()
+{
+    // The LiveKit log bridge's actual use case: a signaling URL embedded in
+    // a free-form SDK log line, not a bare query string.
+    ST_ASSERT_EQ(ApiClient::redactSensitiveParams(
+                     "connecting to wss://lk.example.com/rtc?access_token=eyJhbGciOiJIUzI1NiJ9.abc.def&x=1"),
+                 std::string("connecting to wss://lk.example.com/rtc?access_token=<redacted>&x=1"));
+
+    // A value can be terminated by a quote or whitespace, not just '&', since
+    // this scrubs arbitrary text rather than a URL/query string.
+    ST_ASSERT_EQ(ApiClient::redactSensitiveParams("url=\"wss://h/rtc?access_token=secret\" state=connecting"),
+                 std::string("url=\"wss://h/rtc?access_token=<redacted>\" state=connecting"));
+
+    // "key=" is also scrubbed, matching redactedUrl's convention.
+    ST_ASSERT_EQ(ApiClient::redactSensitiveParams("GET https://h/api/obs/r/slots?key=secret"),
+                 std::string("GET https://h/api/obs/r/slots?key=<redacted>"));
+
+    // Both params can appear in the same message, and each is independently
+    // redacted.
+    ST_ASSERT_EQ(
+        ApiClient::redactSensitiveParams("a access_token=tok1 b key=tok2 c"),
+        std::string("a access_token=<redacted> b key=<redacted> c"));
+
+    // Text with neither parameter passes through unchanged.
+    ST_ASSERT_EQ(ApiClient::redactSensitiveParams("livekit: participant joined"),
+                 std::string("livekit: participant joined"));
+
+    // A value at the very end of the string is still bounded correctly.
+    ST_ASSERT_EQ(ApiClient::redactSensitiveParams("token was access_token=trailing"),
+                 std::string("token was access_token=<redacted>"));
+}
+
+void testRequestShape()
+{
+    auto fake = makeFake(200, R"({"slots":[]})");
+    ApiClient client(fake);
+    ConnectionConfig config = testConfig();
+    // Values that need encoding, and stray whitespace an operator would paste.
+    config.room_slug = " main room ";
+    config.read_key = " a+b/c ";
+    (void)client.fetchSlots(config);
+    ST_ASSERT_EQ(fake->last.method, std::string("GET"));
+    ST_ASSERT_EQ(fake->last.url,
+                 std::string("https://streamers.example.com/api/obs/main%20room/slots?key=a%2Bb%2Fc"));
+
+    auto fake2 = makeFake(200, R"({"lkToken":"t","wsUrl":"wss://x","identity":"obs:r:1"})");
+    ApiClient client2(fake2);
+    (void)client2.requestToken(testConfig());
+    ST_ASSERT_EQ(fake2->last.method, std::string("POST"));
+    ST_ASSERT_EQ(fake2->last.url,
+                 std::string("https://streamers.example.com/api/obs/main-room/token?key=readkey123"));
+    ST_ASSERT_EQ(fake2->last.content_type, std::string("application/json"));
+}
+
+// ---------------------------------------------------------------------------
+// Response parsing
+// ---------------------------------------------------------------------------
+
+void testSlotsHappyPath()
+{
+    auto fake = makeFake(200,
+                         R"({"slots":[{"identity":"cam1","displayName":"Alice","live":true},)"
+                         R"({"identity":"cam2","displayName":"Bob","live":false}]})");
+    ApiClient client(fake);
+    const SlotsResult result = client.fetchSlots(testConfig());
+    ST_ASSERT(result.ok());
+    ST_ASSERT_EQ(result.slots.size(), std::size_t(2));
+    ST_ASSERT_EQ(result.slots[0].identity, std::string("cam1"));
+    ST_ASSERT_EQ(result.slots[0].display_name, std::string("Alice"));
+    ST_ASSERT_EQ(result.slots[0].live, true);
+    ST_ASSERT_EQ(result.slots[1].live, false);
+}
+
+void testSlotsEdgeCases()
+{
+    // Empty room: a valid answer, not an error.
+    {
+        ApiClient client(makeFake(200, R"({"slots":[]})"));
+        const SlotsResult result = client.fetchSlots(testConfig());
+        ST_ASSERT(result.ok());
+        ST_ASSERT_EQ(result.slots.size(), std::size_t(0));
+    }
+    // A missing/blank displayName falls back to the identity, matching what
+    // the server itself does for a slot with no display_name.
+    {
+        ApiClient client(makeFake(200, R"({"slots":[{"identity":"cam1"},{"identity":"cam2","displayName":""}]})"));
+        const SlotsResult result = client.fetchSlots(testConfig());
+        ST_ASSERT(result.ok());
+        ST_ASSERT_EQ(result.slots.size(), std::size_t(2));
+        ST_ASSERT_EQ(result.slots[0].display_name, std::string("cam1"));
+        ST_ASSERT_EQ(result.slots[1].display_name, std::string("cam2"));
+        ST_ASSERT_EQ(result.slots[0].live, false); // missing `live` is not live
+    }
+    // An entry with no identity is unusable and is dropped, not surfaced as a
+    // dropdown row that could never connect.
+    {
+        ApiClient client(makeFake(200, R"({"slots":[{"displayName":"ghost"},{"identity":"cam1"}]})"));
+        const SlotsResult result = client.fetchSlots(testConfig());
+        ST_ASSERT(result.ok());
+        ST_ASSERT_EQ(result.slots.size(), std::size_t(1));
+        ST_ASSERT_EQ(result.slots[0].identity, std::string("cam1"));
+    }
+    // Wrong types where the shape is otherwise right: don't crash, don't
+    // invent values.
+    {
+        ApiClient client(makeFake(200, R"({"slots":[{"identity":"cam1","displayName":42,"live":"yes"}]})"));
+        const SlotsResult result = client.fetchSlots(testConfig());
+        ST_ASSERT(result.ok());
+        ST_ASSERT_EQ(result.slots.size(), std::size_t(1));
+        ST_ASSERT_EQ(result.slots[0].display_name, std::string("cam1"));
+        ST_ASSERT_EQ(result.slots[0].live, false);
+    }
+}
+
+void testTokenHappyPath()
+{
+    ApiClient client(makeFake(200,
+                              R"({"lkToken":"eyJhbGciOiJIUzI1NiJ9.abc.def",)"
+                              R"("wsUrl":"wss://streamers.example.com","identity":"obs:main-room:Ab_1"})"));
+    const TokenResult result = client.requestToken(testConfig());
+    ST_ASSERT(result.ok());
+    ST_ASSERT_EQ(result.lk_token, std::string("eyJhbGciOiJIUzI1NiJ9.abc.def"));
+    ST_ASSERT_EQ(result.ws_url, std::string("wss://streamers.example.com"));
+    ST_ASSERT_EQ(result.identity, std::string("obs:main-room:Ab_1"));
+}
+
+void testHttpErrorStatuses()
+{
+    // 404 -- a wrong read key and an unknown slug are deliberately
+    // indistinguishable server-side, so the message must not claim to know.
+    {
+        ApiClient client(makeFake(404, R"({"error":"not found"})"));
+        const SlotsResult slots = client.fetchSlots(testConfig());
+        ST_ASSERT(!slots.ok());
+        ST_ASSERT(slots.status == ApiStatus::NotFound);
+        ST_ASSERT_EQ(slots.slots.size(), std::size_t(0));
+
+        const TokenResult token = client.requestToken(testConfig());
+        ST_ASSERT(token.status == ApiStatus::NotFound);
+        ST_ASSERT_EQ(token.lk_token, std::string(""));
+    }
+    // 503 -- server reachable, LiveKit not configured.
+    {
+        ApiClient client(makeFake(503, R"({"error":"livekit not configured"})"));
+        ST_ASSERT(client.fetchSlots(testConfig()).status == ApiStatus::Unavailable);
+        ST_ASSERT(client.requestToken(testConfig()).status == ApiStatus::Unavailable);
+    }
+    // Anything else, e.g. a reverse proxy answering before the app does.
+    {
+        ApiClient client(makeFake(502, "<html>502 Bad Gateway</html>"));
+        const SlotsResult result = client.fetchSlots(testConfig());
+        ST_ASSERT(result.status == ApiStatus::HttpError);
+        ST_ASSERT_EQ(result.message, std::string("HTTP 502"));
+    }
+    {
+        ApiClient client(makeFake(401, ""));
+        ST_ASSERT(client.fetchSlots(testConfig()).status == ApiStatus::HttpError);
+    }
+}
+
+void testMalformedSuccessBodies()
+{
+    // 200 with a body that is not the expected shape must be reported, not
+    // silently treated as "no slots".
+    const char *bad_slots[] = {
+        "",
+        "not json at all",
+        "{}",
+        R"({"slots":null})",
+        R"({"slots":{}})",
+        R"({"slots":"cam1"})",
+        "[]",
+        R"({"slots":[)",
+        "<!DOCTYPE html><html>login page</html>",
+    };
+    for (const char *body : bad_slots) {
+        ApiClient client(makeFake(200, body));
+        const SlotsResult result = client.fetchSlots(testConfig());
+        ST_ASSERT(result.status == ApiStatus::MalformedResponse);
+        ST_ASSERT_EQ(result.slots.size(), std::size_t(0));
+    }
+
+    const char *bad_token[] = {
+        "",
+        "{}",
+        R"({"lkToken":""})",
+        R"({"lkToken":"t"})",                    // no wsUrl
+        R"({"wsUrl":"wss://x"})",                // no token
+        R"({"lkToken":123,"wsUrl":"wss://x"})",  // wrong type
+        R"({"lkToken":"t","wsUrl":""})",
+        "[]",
+        "\xff\xfe binary",
+    };
+    for (const char *body : bad_token) {
+        ApiClient client(makeFake(200, body));
+        const TokenResult result = client.requestToken(testConfig());
+        ST_ASSERT(result.status == ApiStatus::MalformedResponse);
+        ST_ASSERT_EQ(result.lk_token, std::string(""));
+    }
+}
+
+void testNetworkErrorAndInvalidConfig()
+{
+    {
+        auto fake = std::make_shared<FakeHttpClient>();
+        fake->next.network_error = "Could not resolve host";
+        ApiClient client(fake);
+        const SlotsResult result = client.fetchSlots(testConfig());
+        ST_ASSERT(result.status == ApiStatus::NetworkError);
+        ST_ASSERT_EQ(result.message, std::string("Could not resolve host"));
+    }
+    // An incomplete config must never reach the HTTP layer at all.
+    {
+        auto fake = makeFake(200, R"({"slots":[]})");
+        ApiClient client(fake);
+        ST_ASSERT(client.fetchSlots(ConnectionConfig{"", "r", "k"}).status == ApiStatus::InvalidConfig);
+        ST_ASSERT(client.fetchSlots(ConnectionConfig{"https://h", "", "k"}).status == ApiStatus::InvalidConfig);
+        ST_ASSERT(client.fetchSlots(ConnectionConfig{"https://h", "r", ""}).status == ApiStatus::InvalidConfig);
+        ST_ASSERT(client.requestToken(ConnectionConfig{"https://", "r", "k"}).status == ApiStatus::InvalidConfig);
+        ST_ASSERT_EQ(fake->calls, 0);
+    }
+    // A null HTTP client is a programming error, not a crash.
+    {
+        ApiClient client(nullptr);
+        ST_ASSERT(client.fetchSlots(testConfig()).status == ApiStatus::InvalidConfig);
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Real platform HTTP backend, against a real loopback socket
+// ---------------------------------------------------------------------------
+
+ConnectionConfig loopbackConfig(const sttest::LoopbackServer &server)
+{
+    return ConnectionConfig{server.baseUrl(), "main-room", "readkey123"};
+}
+
+void testPlatformBackendAgainstLoopback()
+{
+    std::shared_ptr<HttpClient> http(createPlatformHttpClient());
+    ST_ASSERT(http != nullptr);
+    if (!http)
+        return;
+    ApiClient client(http);
+
+    // 200 with real slots, and the request line/headers the server sees.
+    {
+        sttest::LoopbackServer server([](const std::string &) {
+            return sttest::httpResponse(200, "OK",
+                                        R"({"slots":[{"identity":"cam1","displayName":"Alice","live":true}]})");
+        });
+        ST_ASSERT(server.valid());
+        const SlotsResult result = client.fetchSlots(loopbackConfig(server));
+        ST_ASSERT(result.ok());
+        ST_ASSERT_EQ(result.slots.size(), std::size_t(1));
+        ST_ASSERT_EQ(result.slots[0].identity, std::string("cam1"));
+        ST_ASSERT(server.lastRequest().find("GET /api/obs/main-room/slots?key=readkey123") == 0);
+    }
+
+    // POST /token: verify the method and that a body is actually sent.
+    {
+        sttest::LoopbackServer server([](const std::string &) {
+            return sttest::httpResponse(200, "OK", R"({"lkToken":"tok","wsUrl":"wss://lk.example","identity":"obs:r:1"})");
+        });
+        ST_ASSERT(server.valid());
+        const TokenResult result = client.requestToken(loopbackConfig(server));
+        ST_ASSERT(result.ok());
+        ST_ASSERT_EQ(result.lk_token, std::string("tok"));
+        ST_ASSERT_EQ(result.ws_url, std::string("wss://lk.example"));
+        ST_ASSERT(server.lastRequest().find("POST /api/obs/main-room/token?key=readkey123") == 0);
+    }
+
+    // 404 and 503 over a real socket.
+    {
+        sttest::LoopbackServer server([](const std::string &) {
+            return sttest::httpResponse(404, "Not Found", R"({"error":"not found"})");
+        });
+        ST_ASSERT(client.fetchSlots(loopbackConfig(server)).status == ApiStatus::NotFound);
+    }
+    {
+        sttest::LoopbackServer server([](const std::string &) {
+            return sttest::httpResponse(503, "Service Unavailable", R"({"error":"livekit not configured"})");
+        });
+        ST_ASSERT(client.requestToken(loopbackConfig(server)).status == ApiStatus::Unavailable);
+    }
+
+    // 200 with a truncated JSON body: must be MalformedResponse, not a hang
+    // and not a crash.
+    {
+        sttest::LoopbackServer server([](const std::string &) {
+            return sttest::httpResponse(200, "OK", R"({"slots":[{"identity":)");
+        });
+        ST_ASSERT(client.fetchSlots(loopbackConfig(server)).status == ApiStatus::MalformedResponse);
+    }
+
+    // A server that accepts the connection and closes without replying at
+    // all. This is a network error, and it must come back promptly.
+    {
+        sttest::LoopbackServer server([](const std::string &) { return std::string(); });
+        const auto start = std::chrono::steady_clock::now();
+        const SlotsResult result = client.fetchSlots(loopbackConfig(server));
+        const auto elapsed = std::chrono::steady_clock::now() - start;
+        ST_ASSERT(result.status == ApiStatus::NetworkError);
+        ST_ASSERT(std::chrono::duration_cast<std::chrono::seconds>(elapsed).count() < 15);
+    }
+
+    // Garbage that is not HTTP at all.
+    {
+        sttest::LoopbackServer server([](const std::string &) { return std::string("\x01\x02not http\r\n\r\n"); });
+        const SlotsResult result = client.fetchSlots(loopbackConfig(server));
+        ST_ASSERT(result.status == ApiStatus::NetworkError || result.status == ApiStatus::MalformedResponse ||
+                  result.status == ApiStatus::HttpError);
+    }
+
+    // Nothing listening on the port at all: a clean NetworkError.
+    {
+        int dead_port = 0;
+        {
+            sttest::LoopbackServer server([](const std::string &) { return std::string(); });
+            dead_port = server.port();
+        } // server destroyed, port closed
+        ConnectionConfig config{"http://127.0.0.1:" + std::to_string(dead_port), "main-room", "readkey123"};
+        ST_ASSERT(client.fetchSlots(config).status == ApiStatus::NetworkError);
+    }
+}
+
+void testPlatformBackendTimeout()
+{
+    // A server that accepts and then stalls. The plugin must give up on its
+    // own timeout rather than blocking an OBS thread indefinitely.
+    sttest::LoopbackServer server([](const std::string &) {
+        std::this_thread::sleep_for(std::chrono::seconds(5));
+        return sttest::httpResponse(200, "OK", R"({"slots":[]})");
+    });
+    ST_ASSERT(server.valid());
+
+    std::shared_ptr<HttpClient> http(createPlatformHttpClient());
+    HttpRequest request;
+    request.url = server.baseUrl() + "/api/obs/main-room/slots?key=k";
+    request.timeout_ms = 700;
+
+    const auto start = std::chrono::steady_clock::now();
+    const HttpResponse response = http->send(request);
+    const auto elapsed = std::chrono::steady_clock::now() - start;
+    ST_ASSERT(!response.ok());
+    ST_ASSERT(std::chrono::duration_cast<std::chrono::milliseconds>(elapsed).count() < 4000);
+}
+
+} // namespace
+
+int main()
+{
+    testNormalizeServerUrl();
+    testUrlEncodeAndRedaction();
+    testRedactSensitiveParams();
+    testRequestShape();
+    testSlotsHappyPath();
+    testSlotsEdgeCases();
+    testTokenHappyPath();
+    testHttpErrorStatuses();
+    testMalformedSuccessBodies();
+    testNetworkErrorAndInvalidConfig();
+    testPlatformBackendAgainstLoopback();
+    testPlatformBackendTimeout();
+    return st_test_report("api_client");
+}

core/tests/test_core.cpp

@@ -16,44 +16,48 @@ You should have received a copy of the GNU General Public License along
 with this program. If not, see <https://www.gnu.org/licenses/>
 */
 
-// Deliberately dependency-free (no gtest/catch2 etc.) so this test target
+// NOTE on why this file uses ST_ASSERT and not assert(): CI builds Release,
-// has no network fetch or package-manager step in CI -- proving the
+// which defines NDEBUG, which compiles every bare assert() out entirely. This
-// "core library builds and tests headlessly, no OBS required" claim
+// suite previously passed unconditionally for exactly that reason. The
-// without adding another moving part to this scaffolding pass.
+// ST_ASSERT macros in test_util.h are always live and report a pass/fail
+// count.
 
-#include <cassert>
-#include <cstdio>
 #include <cstring>
+#include <string>
 
 #include "stplugin/core.h"
 #include "stplugin/core_c.h"
+#include "test_util.h"
 
-int main() {
+int main()
-    // core_version() should return a non-empty string, via both the
+{
-    // C++ API and the C ABI wrapper the OBS adapter will actually call.
+    // The version string comes through both the C++ API and the C ABI
+    // wrapper, and the two must agree.
     const char *cpp_version = stplugin::core_version();
-    assert(cpp_version != nullptr);
+    ST_ASSERT(cpp_version != nullptr);
-    assert(std::strlen(cpp_version) > 0);
+    ST_ASSERT(cpp_version != nullptr && std::strlen(cpp_version) > 0);
 
     const char *c_version = stplugin_core_version();
-    assert(c_version != nullptr);
+    ST_ASSERT(c_version != nullptr);
-    assert(std::strcmp(cpp_version, c_version) == 0);
+    ST_ASSERT_EQ(std::string(cpp_version ? cpp_version : ""), std::string(c_version ? c_version : ""));
 
-    // ConnectionConfig::is_valid() -- trivial non-empty checks, but
+    // It is the version CMake injected, not a hand-maintained literal.
-    // exercised through all four combinations to prove the core library
+    ST_ASSERT_EQ(std::string(cpp_version ? cpp_version : ""), std::string(STPLUGIN_EXPECTED_CORE_VERSION));
-    // is genuinely testable in isolation.
-    stplugin::ConnectionConfig valid{"https://streamers.example.com", "main-room", "readkey123"};
-    assert(valid.is_valid());
 
-    stplugin::ConnectionConfig missing_url{"", "main-room", "readkey123"};
+    // ConnectionConfig::is_valid(): all three fields are required. Named
-    assert(!missing_url.is_valid());
+    // locals rather than braced temporaries inline, because the commas inside
+    // a braced initialiser would be read as macro argument separators.
+    const stplugin::ConnectionConfig complete{"https://streamers.example.com", "main-room", "readkey123"};
+    const stplugin::ConnectionConfig no_url{"", "main-room", "readkey123"};
+    const stplugin::ConnectionConfig no_slug{"https://streamers.example.com", "", "readkey123"};
+    const stplugin::ConnectionConfig no_key{"https://streamers.example.com", "main-room", ""};
+    const stplugin::ConnectionConfig empty;
 
-    stplugin::ConnectionConfig missing_slug{"https://streamers.example.com", "", "readkey123"};
+    ST_ASSERT(complete.is_valid());
-    assert(!missing_slug.is_valid());
+    ST_ASSERT(!no_url.is_valid());
+    ST_ASSERT(!no_slug.is_valid());
+    ST_ASSERT(!no_key.is_valid());
+    ST_ASSERT(!empty.is_valid());
 
-    stplugin::ConnectionConfig missing_key{"https://streamers.example.com", "main-room", ""};
+    return st_test_report("core");
-    assert(!missing_key.is_valid());
-
-    std::printf("core: all tests passed\n");
-    return 0;
 }

core/tests/test_integration_livekit.cpp

@@ -0,0 +1,370 @@
+/*
+streamer-tools OBS Camera Plugin - LiveKit end-to-end integration test
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+// The one test that proves the session wrapper actually receives media.
+//
+// It publishes a synthetic camera into a real LiveKit room using the same
+// SDK, subscribes to it through stplugin::LiveKitSession, and asserts that
+// decoded frames arrive with the geometry the OBS adapter is going to hand
+// to obs_source_output_video. It also drives the publisher-swap sequence
+// (unpublish, republish) that motivated this whole plugin, and asserts the
+// wrapper recovers instead of going stale or erroring out.
+//
+// It needs a reachable LiveKit server, so it SKIPS (exit 0) unless these are
+// set -- CI on the three build runners has no server, and this must not turn
+// into a red build there:
+//
+//   STPLUGIN_IT_URL                ws://127.0.0.1:7880
+//   STPLUGIN_IT_PUBLISH_TOKEN      JWT: roomJoin + canPublish for the room
+//   STPLUGIN_IT_SUBSCRIBE_TOKEN    JWT: roomJoin + canSubscribe for the room
+//   STPLUGIN_IT_PUBLISHER_IDENTITY the identity in the publish token
+//
+// scripts/livekit-dev-room.py mints all four against a `livekit-server --dev`.
+
+#include <atomic>
+#include <chrono>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <functional>
+#include <memory>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include <livekit/audio_frame.h>
+#include <livekit/audio_source.h>
+#include <livekit/livekit.h>
+#include <livekit/local_audio_track.h>
+#include <livekit/local_participant.h>
+#include <livekit/local_track_publication.h>
+#include <livekit/local_video_track.h>
+#include <livekit/room.h>
+#include <livekit/video_frame.h>
+#include <livekit/video_source.h>
+
+#include "stplugin/session.h"
+#include "test_util.h"
+
+using namespace stplugin;
+
+namespace {
+
+constexpr int kWidth = 320;
+constexpr int kHeight = 240;
+
+std::string envOrEmpty(const char *name)
+{
+    const char *value = std::getenv(name);
+    return value ? std::string(value) : std::string();
+}
+
+/// A moving horizontal band, so a frozen or stale frame is distinguishable
+/// from a live one by luma alone.
+livekit::VideoFrame makeFrame(int tick)
+{
+    livekit::VideoFrame frame = livekit::VideoFrame::create(kWidth, kHeight, livekit::VideoBufferType::I420);
+    std::uint8_t *data = frame.data();
+    const std::size_t luma = static_cast<std::size_t>(kWidth) * kHeight;
+    std::memset(data, 16, luma);
+    const int band = (tick * 7) % kHeight;
+    std::memset(data + static_cast<std::size_t>(band) * kWidth, 235, kWidth);
+    std::memset(data + luma, 128, frame.dataSize() - luma);
+    return frame;
+}
+
+void step(const char *what)
+{
+    std::printf("  step: %s\n", what);
+    std::fflush(stdout);
+}
+
+bool waitFor(const std::function<bool()> &predicate, int timeout_ms)
+{
+    const auto deadline = std::chrono::steady_clock::now() + std::chrono::milliseconds(timeout_ms);
+    while (std::chrono::steady_clock::now() < deadline) {
+        if (predicate())
+            return true;
+        std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    }
+    return predicate();
+}
+
+struct Publisher {
+    livekit::Room room;
+    std::shared_ptr<livekit::VideoSource> video_source;
+    std::shared_ptr<livekit::LocalVideoTrack> video_track;
+    std::shared_ptr<livekit::AudioSource> audio_source;
+    std::shared_ptr<livekit::LocalAudioTrack> audio_track;
+    std::thread pump;
+    std::atomic<bool> stop{false};
+    std::string video_sid;
+
+    bool connect(const std::string &url, const std::string &token)
+    {
+        livekit::RoomOptions options;
+        options.auto_subscribe = false;
+        options.connect_timeout = std::chrono::milliseconds(10000);
+        return room.connect(url, token, options);
+    }
+
+    bool publishVideo()
+    {
+        auto local = room.localParticipant().lock();
+        if (!local)
+            return false;
+        video_source = std::make_shared<livekit::VideoSource>(kWidth, kHeight);
+        video_track = livekit::LocalVideoTrack::createLocalVideoTrack("camera", video_source);
+        livekit::TrackPublishOptions options;
+        options.source = livekit::TrackSource::SOURCE_CAMERA;
+        options.simulcast = false;
+        local->publishTrack(video_track, options);
+        // publishTrack is async server-side; the SID appears on the track once
+        // the publication lands.
+        for (int i = 0; i < 100 && video_track->sid().empty(); ++i)
+            std::this_thread::sleep_for(std::chrono::milliseconds(50));
+        video_sid = video_track->sid();
+        return !video_sid.empty();
+    }
+
+    bool publishAudio()
+    {
+        auto local = room.localParticipant().lock();
+        if (!local)
+            return false;
+        audio_source = std::make_shared<livekit::AudioSource>(48000, 1);
+        audio_track = livekit::LocalAudioTrack::createLocalAudioTrack("microphone", audio_source);
+        livekit::TrackPublishOptions options;
+        options.source = livekit::TrackSource::SOURCE_MICROPHONE;
+        local->publishTrack(audio_track, options);
+        for (int i = 0; i < 100 && audio_track->sid().empty(); ++i)
+            std::this_thread::sleep_for(std::chrono::milliseconds(50));
+        return !audio_track->sid().empty();
+    }
+
+    bool unpublishVideo()
+    {
+        auto local = room.localParticipant().lock();
+        if (!local)
+            return false;
+        // The FFI keys local publications by the *publication* SID, which is
+        // not necessarily the track SID -- unpublishing by track SID throws
+        // "track not found".
+        std::string sid = video_sid;
+        if (video_track && video_track->publication())
+            sid = video_track->publication()->sid();
+        if (sid.empty())
+            return false;
+        try {
+            local->unpublishTrack(sid);
+        } catch (const std::exception &e) {
+            std::printf("  unpublishTrack(%s) threw: %s\n", sid.c_str(), e.what());
+            std::fflush(stdout);
+            return false;
+        }
+        video_sid.clear();
+        video_track.reset();
+        video_source.reset();
+        return true;
+    }
+
+    void startPump()
+    {
+        stop.store(false);
+        pump = std::thread([this] {
+            int tick = 0;
+            std::vector<std::int16_t> pcm(480, 0); // 10ms of 48kHz mono
+            while (!stop.load()) {
+                if (video_source) {
+                    livekit::VideoFrame frame = makeFrame(tick);
+                    video_source->captureFrame(frame, static_cast<std::int64_t>(tick) * 33333);
+                }
+                if (audio_source) {
+                    for (std::size_t i = 0; i < pcm.size(); ++i)
+                        pcm[i] = static_cast<std::int16_t>(((tick * 480 + static_cast<int>(i)) % 100) * 100);
+                    livekit::AudioFrame audio(pcm, 48000, 1, static_cast<int>(pcm.size()));
+                    audio_source->captureFrame(audio);
+                }
+                ++tick;
+                std::this_thread::sleep_for(std::chrono::milliseconds(33));
+            }
+        });
+    }
+
+    void stopPump()
+    {
+        stop.store(true);
+        if (pump.joinable())
+            pump.join();
+    }
+
+    ~Publisher()
+    {
+        stopPump();
+        room.disconnect(livekit::DisconnectReason::ClientInitiated);
+    }
+};
+
+} // namespace
+
+int main()
+{
+    const std::string url = envOrEmpty("STPLUGIN_IT_URL");
+    const std::string publish_token = envOrEmpty("STPLUGIN_IT_PUBLISH_TOKEN");
+    const std::string subscribe_token = envOrEmpty("STPLUGIN_IT_SUBSCRIBE_TOKEN");
+    const std::string publisher_identity = envOrEmpty("STPLUGIN_IT_PUBLISHER_IDENTITY");
+
+    if (url.empty() || publish_token.empty() || subscribe_token.empty() || publisher_identity.empty()) {
+        std::printf("integration_livekit: SKIPPED (STPLUGIN_IT_* not set)\n");
+        return 0;
+    }
+
+    LiveKitSession::globalInitialize();
+
+    auto publisher_holder = std::make_unique<Publisher>();
+    Publisher &publisher = *publisher_holder;
+    step("publisher connect");
+    ST_ASSERT(publisher.connect(url, publish_token));
+    step("publish video");
+    ST_ASSERT(publisher.publishVideo());
+    step("publish audio");
+    ST_ASSERT(publisher.publishAudio());
+    publisher.startPump();
+
+    // --- subscribe through the wrapper under test --------------------------
+
+    std::atomic<int> video_frames{0};
+    std::atomic<int> audio_frames{0};
+    std::atomic<int> bad_frames{0};
+    std::atomic<int> full_size_frames{0};
+    std::atomic<int> last_width{0};
+    std::atomic<int> last_height{0};
+    std::atomic<int> last_planes{0};
+    std::atomic<long long> last_timestamp{0};
+    std::atomic<int> last_sample_rate{0};
+    std::atomic<int> last_channels{0};
+
+    LiveKitSession session;
+    session.setVideoHandler([&](const VideoFrameData &frame) {
+        // Everything the OBS adapter is about to dereference must be sane --
+        // checked against the frame's OWN geometry, not the publisher's.
+        // WebRTC ramps a new subscription up from a downscaled spatial layer,
+        // so the first frames after (re)subscribing legitimately arrive
+        // smaller than what is being published; the adapter has to cope with
+        // a mid-stream resolution change, and so does this assertion.
+        const std::uint32_t chroma_stride = static_cast<std::uint32_t>((frame.width + 1) / 2);
+        const bool sane = frame.width > 0 && frame.height > 0 && frame.format == PixelFormat::I420 &&
+                          frame.plane_count == 3 && frame.data != nullptr &&
+                          frame.size >= expectedFrameBytes(frame.format, frame.width, frame.height) &&
+                          frame.planes[0].data != nullptr && frame.planes[1].data != nullptr &&
+                          frame.planes[2].data != nullptr &&
+                          frame.planes[0].stride >= static_cast<std::uint32_t>(frame.width) &&
+                          frame.planes[1].stride >= chroma_stride && frame.planes[2].stride >= chroma_stride;
+        if (!sane)
+            bad_frames.fetch_add(1);
+        if (frame.width == kWidth && frame.height == kHeight)
+            full_size_frames.fetch_add(1);
+        last_width.store(frame.width);
+        last_height.store(frame.height);
+        last_planes.store(frame.plane_count);
+        last_timestamp.store(static_cast<long long>(frame.timestamp_us));
+        video_frames.fetch_add(1);
+    });
+    session.setAudioHandler([&](const AudioFrameData &frame) {
+        last_sample_rate.store(frame.sample_rate);
+        last_channels.store(frame.channels);
+        audio_frames.fetch_add(1);
+    });
+
+    std::atomic<int> state_changes{0};
+    session.setStateHandler([&](SessionState, const std::string &) { state_changes.fetch_add(1); });
+
+    SessionConfig config;
+    config.ws_url = url;
+    config.token = subscribe_token;
+    config.participant_identity = publisher_identity;
+    config.connect_timeout_ms = 10000;
+
+    step("subscriber connect");
+    ST_ASSERT(session.connect(config));
+    ST_ASSERT(session.state() == SessionState::Connected);
+
+    ST_ASSERT(waitFor([&] { return video_frames.load() >= 15; }, 25000));
+    ST_ASSERT(session.hasVideo());
+    ST_ASSERT(!session.waitingForCamera());
+    ST_ASSERT_EQ(bad_frames.load(), 0);
+    ST_ASSERT_EQ(last_planes.load(), 3);
+    // The stream must actually reach the published resolution, not just
+    // deliver ramp-up frames forever.
+    ST_ASSERT(waitFor([&] { return full_size_frames.load() > 0; }, 20000));
+    ST_ASSERT_EQ(last_width.load(), kWidth);
+    ST_ASSERT_EQ(last_height.load(), kHeight);
+    ST_ASSERT(last_timestamp.load() > 0);
+    ST_ASSERT(session.videoFrameCount() >= 15);
+
+    ST_ASSERT(waitFor([&] { return audio_frames.load() >= 10; }, 20000));
+    ST_ASSERT(session.hasAudio());
+    ST_ASSERT_EQ(last_sample_rate.load(), 48000);
+    ST_ASSERT(last_channels.load() >= 1);
+
+    // --- publisher swap: the bug this plugin exists to make impossible -----
+
+    const int before_swap = video_frames.load();
+    publisher.stopPump();
+    step("unpublish video");
+    ST_ASSERT(publisher.unpublishVideo());
+
+    ST_ASSERT(waitFor([&] { return !session.hasVideo(); }, 15000));
+    // An unpublished camera is the placeholder state, never a failure: the
+    // room connection itself is untouched.
+    ST_ASSERT(session.state() == SessionState::Connected);
+    ST_ASSERT(session.waitingForCamera());
+
+    // No frames may keep arriving from the dead publisher.
+    const int after_unpublish = video_frames.load();
+    std::this_thread::sleep_for(std::chrono::milliseconds(1500));
+    ST_ASSERT_EQ(video_frames.load(), after_unpublish);
+    ST_ASSERT(after_unpublish >= before_swap);
+
+    // Republish, exactly as a reconnecting browser would.
+    step("republish video");
+    ST_ASSERT(publisher.publishVideo());
+    publisher.startPump();
+
+    ST_ASSERT(waitFor([&] { return video_frames.load() >= after_unpublish + 15; }, 25000));
+    ST_ASSERT(session.hasVideo());
+    ST_ASSERT(session.state() == SessionState::Connected);
+    ST_ASSERT_EQ(bad_frames.load(), 0);
+
+    // --- teardown ----------------------------------------------------------
+
+    step("teardown");
+    publisher.stopPump();
+    session.disconnect();
+    ST_ASSERT(session.state() == SessionState::Disconnected);
+    ST_ASSERT(!session.hasVideo());
+
+    // The publisher's Room must be torn down while the SDK is still
+    // initialized, or its FFI disconnect fails on the way out.
+    publisher_holder.reset();
+    LiveKitSession::globalShutdown();
+
+    std::printf("integration_livekit: %d video frames, %d audio frames, %d state changes\n", video_frames.load(),
+                audio_frames.load(), state_changes.load());
+    return st_test_report("integration_livekit");
+}

core/tests/test_json.cpp

@@ -0,0 +1,188 @@
+/*
+streamer-tools OBS Camera Plugin - JSON reader tests
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#include <string>
+#include <vector>
+
+#include "stplugin/json.h"
+#include "test_util.h"
+
+using stplugin::json::Value;
+using stplugin::json::parse;
+
+static void testRealResponses()
+{
+    // The exact shape apps/server/src/obs/plugin.routes.ts returns.
+    const Value slots = parse(
+        R"({"slots":[{"identity":"cam1","displayName":"Alice","live":true},)"
+        R"({"identity":"cam2","displayName":"Bob","live":false}]})");
+    ST_ASSERT(slots.valid());
+    ST_ASSERT(slots.isObject());
+    ST_ASSERT(slots["slots"].isArray());
+    ST_ASSERT_EQ(slots["slots"].size(), std::size_t(2));
+    ST_ASSERT_EQ(slots["slots"].at(0)["identity"].asString(), std::string("cam1"));
+    ST_ASSERT_EQ(slots["slots"].at(0)["displayName"].asString(), std::string("Alice"));
+    ST_ASSERT_EQ(slots["slots"].at(0)["live"].asBool(), true);
+    ST_ASSERT_EQ(slots["slots"].at(1)["live"].asBool(true), false);
+
+    const Value token = parse(
+        R"({"lkToken":"eyJhbGciOiJIUzI1NiJ9.abc.def","wsUrl":"wss://streamers.example.com",)"
+        R"("identity":"obs:main-room:Ab_1-cd2"})");
+    ST_ASSERT_EQ(token["lkToken"].asString(), std::string("eyJhbGciOiJIUzI1NiJ9.abc.def"));
+    ST_ASSERT_EQ(token["wsUrl"].asString(), std::string("wss://streamers.example.com"));
+    ST_ASSERT_EQ(token["identity"].asString(), std::string("obs:main-room:Ab_1-cd2"));
+
+    const Value error = parse(R"({"error":"not found"})");
+    ST_ASSERT_EQ(error["error"].asString(), std::string("not found"));
+}
+
+// One backslash, as it appears in the JSON *text* being parsed.
+//
+// Every JSON input below that contains a backslash is built by concatenation
+// rather than written as a literal. Two separate portability problems make
+// the obvious spellings unsafe, both observed on the Windows CI runner:
+//   - MSVC still forms escape sequences and universal-character-names inside
+//     RAW string literals, which it must not: R"( ... backslash-u-d-8-3-d ... )"
+//     is a hard compile error ("a universal-character-name specifies an
+//     invalid character"), and a raw string containing backslash-slash is an
+//     "illegal escape sequence".
+//   - A doubled backslash immediately followed by 'u' inside an ordinary
+//     literal sits on a genuinely murky corner of translation phase 1, where
+//     compilers have historically disagreed about whether a
+//     universal-character-name is formed.
+// Concatenation sidesteps both: no backslash is ever adjacent to a 'u' in
+// the source text at all.
+static const std::string kBS = "\\";
+
+static void testScalarsAndEscapes()
+{
+    ST_ASSERT(parse("null").isNull());
+    ST_ASSERT_EQ(parse("true").asBool(), true);
+    ST_ASSERT_EQ(parse("false").asBool(true), false);
+    ST_ASSERT_EQ(parse("0").asNumber(), 0.0);
+    ST_ASSERT_EQ(parse("-12").asNumber(), -12.0);
+    ST_ASSERT_EQ(parse("1.5e2").asNumber(), 150.0);
+    ST_ASSERT_EQ(parse("\"\"").asString("x"), std::string(""));
+
+    // "a\"b\\c\/d"  ->  a"b\c/d
+    ST_ASSERT_EQ(parse("\"a" + kBS + "\"b" + kBS + kBS + "c" + kBS + "/d\"").asString(),
+                 std::string("a\"b\\c/d"));
+    // "\n\t\r\b\f"
+    ST_ASSERT_EQ(parse("\"" + kBS + "n" + kBS + "t" + kBS + "r" + kBS + "b" + kBS + "f\"").asString(),
+                 std::string("\n\t\r\b\f"));
+
+    // \uXXXX escapes, including a surrogate pair (an emoji in a display name
+    // is entirely plausible and must not corrupt the dropdown).
+    ST_ASSERT_EQ(parse("\"" + kBS + "u0041\"").asString(), std::string("A"));
+    ST_ASSERT_EQ(parse("\"caf" + kBS + "u00e9\"").asString(), std::string("caf\xc3\xa9"));
+    ST_ASSERT_EQ(parse("\"" + kBS + "ud83d" + kBS + "ude00\"").asString(),
+                 std::string("\xf0\x9f\x98\x80"));
+
+    // Whitespace everywhere legal.
+    ST_ASSERT_EQ(parse("  {\n \"a\" :\t[ 1 , 2 ]\r\n} ")["a"].size(), std::size_t(2));
+}
+
+static void testMalformedIsRejectedNotCrashed()
+{
+    const std::vector<std::string> bad = {
+        "",
+        "   ",
+        "{",
+        "}",
+        "[",
+        "[1,",
+        "[1,]",
+        "{\"a\"}",
+        "{\"a\":}",
+        "{\"a\":1,}",
+        "{a:1}",
+        "{'a':1}",
+        "\"unterminated",
+        "\"bad" + kBS + "escape\"",     // not a JSON escape character
+        "\"" + kBS + "u00\"",           // truncated code point
+        "\"" + kBS + "uZZZZ\"",         // non-hex code point
+        "\"" + kBS + "ud83d\"",         // lone high surrogate
+        "\"" + kBS + "ude00\"",         // lone low surrogate
+        "01",                            // leading zero
+        "+1",
+        ".5",
+        "1.",
+        "1e",
+        "1e+",
+        "tru",
+        "nulll",
+        "{}garbage",                     // trailing content
+        "[1,2] [3]",
+        "\"raw\ncontrol\"",              // literal control char inside a string
+        "\xff\xfe",                      // binary garbage
+        "<!DOCTYPE html><html><body>502 Bad Gateway</body></html>",
+    };
+    for (const std::string &text : bad) {
+        const Value v = parse(text);
+        ST_ASSERT(!v.valid());
+        // Accessors on an invalid value must still be safe and return the
+        // caller's fallback.
+        ST_ASSERT_EQ(v["anything"].asString("fallback"), std::string("fallback"));
+        ST_ASSERT_EQ(v.at(0).asNumber(-1.0), -1.0);
+        ST_ASSERT_EQ(v.size(), std::size_t(0));
+    }
+}
+
+static void testDepthLimit()
+{
+    // Deep-but-legal nesting is rejected rather than recursed into, so a
+    // hostile response cannot overflow the stack inside OBS.
+    std::string deep;
+    const int depth = stplugin::json::kMaxDepth + 50;
+    for (int i = 0; i < depth; ++i)
+        deep += "[";
+    for (int i = 0; i < depth; ++i)
+        deep += "]";
+    ST_ASSERT(!parse(deep).valid());
+
+    // Just inside the limit still parses.
+    std::string shallow;
+    for (int i = 0; i < stplugin::json::kMaxDepth - 1; ++i)
+        shallow += "[";
+    shallow += "1";
+    for (int i = 0; i < stplugin::json::kMaxDepth - 1; ++i)
+        shallow += "]";
+    ST_ASSERT(parse(shallow).valid());
+}
+
+static void testWrongTypesFallBack()
+{
+    const Value v = parse(R"({"n":5,"s":"x","b":true,"arr":[1],"obj":{}})");
+    ST_ASSERT_EQ(v["n"].asString("fallback"), std::string("fallback"));
+    ST_ASSERT_EQ(v["s"].asNumber(-1.0), -1.0);
+    ST_ASSERT_EQ(v["s"].asBool(true), true);
+    ST_ASSERT_EQ(v["missing"].asString("fallback"), std::string("fallback"));
+    ST_ASSERT_EQ(v["arr"].at(5).asNumber(-1.0), -1.0);
+    ST_ASSERT_EQ(v["obj"].at(0).asNumber(-1.0), -1.0);
+    ST_ASSERT_EQ(v["n"]["deeper"].asString("fallback"), std::string("fallback"));
+}
+
+int main()
+{
+    testRealResponses();
+    testScalarsAndEscapes();
+    testMalformedIsRejectedNotCrashed();
+    testDepthLimit();
+    testWrongTypesFallBack();
+    return st_test_report("json");
+}

core/tests/test_livekit_smoke.cpp

@@ -0,0 +1,64 @@
+/*
+streamer-tools OBS Camera Plugin - LiveKit SDK link smoke test
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+// Proves the pinned client-sdk-cpp release is genuinely linked and callable:
+// the SDK's own global init/shutdown runs in-process without crashing, and
+// the header-reported build version matches the version CMake pinned.
+//
+// This does NOT touch the network -- livekit::initialize() only sets up
+// global SDK state and log routing.
+
+#include <cstdio>
+#include <cstring>
+
+#include <livekit/build.h>
+#include <livekit/livekit.h>
+#include <livekit/logging.h>
+
+#include "test_util.h"
+
+int main()
+{
+    // The pin CMake resolved is passed in as a define; the SDK's own
+    // generated build.h reports what was actually unpacked. A mismatch means
+    // a stale extracted SDK directory is being reused.
+    ST_ASSERT_EQ(std::string(LIVEKIT_BUILD_VERSION), std::string(STPLUGIN_EXPECTED_LIVEKIT_VERSION));
+
+    // initialize() returns true when this call performed the init, false if
+    // the SDK was already initialized. Either way it must not crash, and a
+    // second call must report "already initialized".
+    bool first = livekit::initialize(livekit::LogLevel::Error);
+    ST_ASSERT(first);
+
+    bool second = livekit::initialize(livekit::LogLevel::Error);
+    ST_ASSERT(!second);
+
+    // Log level round-trips through the SDK's global state.
+    livekit::setLogLevel(livekit::LogLevel::Warn);
+    ST_ASSERT(livekit::getLogLevel() == livekit::LogLevel::Warn);
+
+    livekit::shutdown();
+
+    // The SDK documents that initialize() may be called again after
+    // shutdown(); exercise that so a half-torn-down global state would show
+    // up here rather than in OBS.
+    ST_ASSERT(livekit::initialize(livekit::LogLevel::Error));
+    livekit::shutdown();
+
+    return st_test_report("livekit_smoke");
+}

core/tests/test_session.cpp

@@ -0,0 +1,355 @@
+/*
+streamer-tools OBS Camera Plugin - session wrapper tests
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+// What is and is not covered here, stated plainly because it matters:
+//
+//   COVERED headlessly -- the session's own decision-making: the state
+//   machine's transitions (including the publisher-swap and reconnect paths
+//   that motivated this plugin), track selection, frame geometry validation,
+//   and the real connect() failure paths against the real SDK (bad URL,
+//   unreachable host, garbage token).
+//
+//   NOT COVERED here -- anything that needs a LiveKit server to answer:
+//   a successful connect, actual subscription, and actual decoded frames
+//   reaching the handlers. Those can only be verified against a real room,
+//   and the design doc's Testing section puts that in the integration-test /
+//   manual-sign-off bucket.
+
+#include <atomic>
+#include <chrono>
+#include <string>
+#include <thread>
+
+#include "stplugin/session.h"
+#include "stplugin/session_types.h"
+#include "test_util.h"
+
+using namespace stplugin;
+
+namespace {
+
+// ---------------------------------------------------------------------------
+// Pure logic
+// ---------------------------------------------------------------------------
+
+void testFrameGeometry()
+{
+    ST_ASSERT_EQ(planeCount(PixelFormat::I420), 3);
+    ST_ASSERT_EQ(planeCount(PixelFormat::NV12), 2);
+    ST_ASSERT_EQ(planeCount(PixelFormat::BGRA), 1);
+
+    // 1280x720 I420: 921600 luma + 2 * 230400 chroma.
+    ST_ASSERT_EQ(expectedFrameBytes(PixelFormat::I420, 1280, 720), std::size_t(1382400));
+    ST_ASSERT_EQ(expectedFrameBytes(PixelFormat::NV12, 1280, 720), std::size_t(1382400));
+    ST_ASSERT_EQ(expectedFrameBytes(PixelFormat::BGRA, 1280, 720), std::size_t(3686400));
+
+    // Odd dimensions round the chroma planes up, the way libyuv does.
+    ST_ASSERT_EQ(expectedFrameBytes(PixelFormat::I420, 3, 3), std::size_t(9 + 2 * 4));
+    ST_ASSERT_EQ(expectedFrameBytes(PixelFormat::I420, 1, 1), std::size_t(1 + 2));
+
+    // Degenerate geometry is 0, which the reader treats as "drop the frame".
+    ST_ASSERT_EQ(expectedFrameBytes(PixelFormat::I420, 0, 720), std::size_t(0));
+    ST_ASSERT_EQ(expectedFrameBytes(PixelFormat::I420, 1280, 0), std::size_t(0));
+    ST_ASSERT_EQ(expectedFrameBytes(PixelFormat::I420, -1, -1), std::size_t(0));
+
+    ST_ASSERT_EQ(std::string(describePixelFormat(PixelFormat::I420)), std::string("I420"));
+}
+
+void testTrackSelection()
+{
+    const std::string want = "cam1";
+
+    // The camera we asked for.
+    ST_ASSERT(isWantedVideoTrack(want, "cam1", MediaKind::Video, MediaSource::Camera));
+    // A video track with no declared source is taken on kind alone.
+    ST_ASSERT(isWantedVideoTrack(want, "cam1", MediaKind::Video, MediaSource::Unknown));
+
+    // Someone else's camera.
+    ST_ASSERT(!isWantedVideoTrack(want, "cam2", MediaKind::Video, MediaSource::Camera));
+    // The right participant's screenshare is explicitly NOT the camera --
+    // streamer-tools publishes those as separate sources.
+    ST_ASSERT(!isWantedVideoTrack(want, "cam1", MediaKind::Video, MediaSource::Screenshare));
+    // Their microphone is not a video track.
+    ST_ASSERT(!isWantedVideoTrack(want, "cam1", MediaKind::Audio, MediaSource::Microphone));
+    // No selection means nothing matches -- never "the first thing we see".
+    ST_ASSERT(!isWantedVideoTrack("", "cam1", MediaKind::Video, MediaSource::Camera));
+    ST_ASSERT(!isWantedVideoTrack("", "", MediaKind::Video, MediaSource::Camera));
+
+    ST_ASSERT(isWantedAudioTrack(want, "cam1", MediaKind::Audio, MediaSource::Microphone));
+    ST_ASSERT(isWantedAudioTrack(want, "cam1", MediaKind::Audio, MediaSource::Unknown));
+    ST_ASSERT(!isWantedAudioTrack(want, "cam1", MediaKind::Audio, MediaSource::ScreenshareAudio));
+    ST_ASSERT(!isWantedAudioTrack(want, "cam1", MediaKind::Video, MediaSource::Camera));
+    ST_ASSERT(!isWantedAudioTrack(want, "other", MediaKind::Audio, MediaSource::Microphone));
+}
+
+void testStateMachineHappyPath()
+{
+    SessionStateMachine m;
+    ST_ASSERT(m.state() == SessionState::Idle);
+    ST_ASSERT(!m.hasVideo());
+    ST_ASSERT(!m.waitingForCamera());
+
+    m.onConnectRequested();
+    ST_ASSERT(m.state() == SessionState::Connecting);
+    // Connecting is not "waiting for camera": the placeholder belongs to a
+    // live connection with a dark slot, not to a connection in progress.
+    ST_ASSERT(!m.waitingForCamera());
+
+    m.onConnectSucceeded();
+    ST_ASSERT(m.state() == SessionState::Connected);
+    ST_ASSERT(m.waitingForCamera());
+
+    m.onVideoAttached();
+    ST_ASSERT(m.hasVideo());
+    ST_ASSERT(!m.waitingForCamera());
+
+    m.onAudioAttached();
+    ST_ASSERT(m.hasAudio());
+
+    m.onLocalDisconnect();
+    ST_ASSERT(m.state() == SessionState::Disconnected);
+    ST_ASSERT(!m.hasVideo());
+    ST_ASSERT(!m.hasAudio());
+}
+
+void testPublisherSwapIsNotAnError()
+{
+    // The motivating bug: a slot's publisher restarts mid-show. That must
+    // read as "waiting for camera", never as a failure, and the connection
+    // state must not move at all.
+    SessionStateMachine m;
+    m.onConnectRequested();
+    m.onConnectSucceeded();
+    m.onVideoAttached();
+
+    m.onVideoDetached();
+    ST_ASSERT(m.state() == SessionState::Connected);
+    ST_ASSERT(!m.hasVideo());
+    ST_ASSERT(m.waitingForCamera());
+    ST_ASSERT(m.detail().empty());
+
+    m.onVideoAttached();
+    ST_ASSERT(m.state() == SessionState::Connected);
+    ST_ASSERT(m.hasVideo());
+    ST_ASSERT(!m.waitingForCamera());
+}
+
+void testReconnect()
+{
+    SessionStateMachine m;
+    m.onConnectRequested();
+    m.onConnectSucceeded();
+    m.onVideoAttached();
+
+    m.onReconnecting();
+    ST_ASSERT(m.state() == SessionState::Reconnecting);
+    // Tracks are re-subscribed on the far side, so video is not live yet.
+    ST_ASSERT(!m.hasVideo());
+    ST_ASSERT(m.waitingForCamera());
+    ST_ASSERT_EQ(m.detail(), std::string("reconnecting"));
+
+    m.onReconnected();
+    ST_ASSERT(m.state() == SessionState::Connected);
+    ST_ASSERT(m.detail().empty());
+
+    // A stray reconnect notification after a hard failure must not resurrect
+    // the session.
+    SessionStateMachine dead;
+    dead.onConnectRequested();
+    dead.onConnectFailed("token rejected");
+    dead.onReconnecting();
+    ST_ASSERT(dead.state() == SessionState::Failed);
+    dead.onReconnected();
+    ST_ASSERT(dead.state() == SessionState::Failed);
+}
+
+void testFailureAndRecovery()
+{
+    SessionStateMachine m;
+    m.onConnectRequested();
+    m.onConnectFailed("token rejected");
+    ST_ASSERT(m.state() == SessionState::Failed);
+    ST_ASSERT_EQ(m.detail(), std::string("token rejected"));
+    ST_ASSERT(!m.waitingForCamera());
+
+    // A fresh attempt clears the stale reason, so a healthy connection can
+    // never be shown next to the previous failure's message.
+    m.onConnectRequested();
+    ST_ASSERT(m.detail().empty());
+    m.onConnectSucceeded();
+    ST_ASSERT(m.state() == SessionState::Connected);
+    ST_ASSERT(m.detail().empty());
+
+    // A fatal room end (duplicate identity, token rejected) is Failed; an
+    // ordinary drop is Disconnected.
+    SessionStateMachine fatal;
+    fatal.onConnectRequested();
+    fatal.onConnectSucceeded();
+    fatal.onRoomEnded("another client joined with the same identity", true);
+    ST_ASSERT(fatal.state() == SessionState::Failed);
+
+    SessionStateMachine dropped;
+    dropped.onConnectRequested();
+    dropped.onConnectSucceeded();
+    dropped.onRoomEnded("the signalling connection closed", false);
+    ST_ASSERT(dropped.state() == SessionState::Disconnected);
+
+    // Room-ended events after we are already down are ignored, so a late
+    // event cannot overwrite the reason the operator needs to see.
+    SessionStateMachine idle;
+    idle.onRoomEnded("stray", true);
+    ST_ASSERT(idle.state() == SessionState::Idle);
+}
+
+// ---------------------------------------------------------------------------
+// Real SDK, failure paths only (no LiveKit server available headlessly)
+// ---------------------------------------------------------------------------
+
+void testConnectRejectsIncompleteConfig()
+{
+    LiveKitSession session;
+    std::atomic<int> state_calls{0};
+    session.setStateHandler([&](SessionState, const std::string &) { state_calls.fetch_add(1); });
+
+    SessionConfig config;
+    config.ws_url = "";
+    config.token = "t";
+    config.participant_identity = "cam1";
+    ST_ASSERT(!session.connect(config));
+    ST_ASSERT(session.state() == SessionState::Failed);
+    ST_ASSERT(!session.stateDetail().empty());
+
+    config.ws_url = "ws://127.0.0.1:1";
+    config.token = "";
+    ST_ASSERT(!session.connect(config));
+    ST_ASSERT(session.state() == SessionState::Failed);
+
+    config.token = "t";
+    config.participant_identity = "";
+    ST_ASSERT(!session.connect(config));
+    ST_ASSERT(session.state() == SessionState::Failed);
+
+    // The state handler fired for each attempt (Connecting + Failed).
+    ST_ASSERT(state_calls.load() >= 6);
+
+    // Frame counters stay at zero and nothing crashes on teardown.
+    ST_ASSERT_EQ(session.videoFrameCount(), std::uint64_t(0));
+    ST_ASSERT_EQ(session.audioFrameCount(), std::uint64_t(0));
+    session.disconnect();
+    session.disconnect(); // idempotent
+    ST_ASSERT(session.state() == SessionState::Failed || session.state() == SessionState::Disconnected);
+}
+
+void testConnectToUnreachableServerFailsCleanly()
+{
+    // Port 1 on loopback: nothing is listening, and the connection is
+    // refused immediately rather than hanging. This exercises the real
+    // livekit::Room::connect() failure path, with a real (garbage) token.
+    LiveKitSession session;
+    std::atomic<int> video_frames{0};
+    session.setVideoHandler([&](const VideoFrameData &) { video_frames.fetch_add(1); });
+
+    SessionConfig config;
+    config.ws_url = "ws://127.0.0.1:1";
+    config.token = "not.a.real.token";
+    config.participant_identity = "cam1";
+    config.connect_timeout_ms = 3000;
+
+    const auto start = std::chrono::steady_clock::now();
+    const bool ok = session.connect(config);
+    const auto elapsed = std::chrono::steady_clock::now() - start;
+
+    ST_ASSERT(!ok);
+    ST_ASSERT(session.state() == SessionState::Failed);
+    ST_ASSERT(!session.stateDetail().empty());
+    ST_ASSERT_EQ(video_frames.load(), 0);
+    // Must not sit on the caller's thread indefinitely -- this runs on an OBS
+    // thread in the real adapter.
+    ST_ASSERT(std::chrono::duration_cast<std::chrono::seconds>(elapsed).count() < 60);
+
+    session.disconnect();
+}
+
+void testConnectToNonLiveKitServerFailsCleanly()
+{
+    // A URL that resolves and connects but is not a LiveKit signalling
+    // endpoint. The realistic operator mistake: pasting the app URL.
+    LiveKitSession session;
+    SessionConfig config;
+    config.ws_url = "ws://127.0.0.1:1/rtc";
+    config.token = "eyJhbGciOiJIUzI1NiJ9.bm90YXRva2Vu.x";
+    config.participant_identity = "cam1";
+    config.connect_timeout_ms = 3000;
+    ST_ASSERT(!session.connect(config));
+    ST_ASSERT(session.state() == SessionState::Failed);
+    session.disconnect();
+}
+
+void testDestroyWithoutDisconnect()
+{
+    // The OBS adapter destroys sources without necessarily having called
+    // disconnect() first (an OBS shutdown mid-connect, say). The destructor
+    // must join every thread it started rather than terminating.
+    {
+        LiveKitSession session;
+        SessionConfig config;
+        config.ws_url = "ws://127.0.0.1:1";
+        config.token = "t";
+        config.participant_identity = "cam1";
+        config.connect_timeout_ms = 2000;
+        (void)session.connect(config);
+    }
+    ST_ASSERT(true); // reaching here at all is the assertion
+}
+
+void testGlobalInitIsReferenceCounted()
+{
+    // Several OBS sources may each hold the SDK open; the last one out turns
+    // the lights off, and an unbalanced extra shutdown must not underflow.
+    LiveKitSession::globalInitialize();
+    LiveKitSession::globalInitialize();
+    LiveKitSession::globalShutdown();
+    LiveKitSession::globalShutdown();
+    LiveKitSession::globalShutdown(); // extra, must be harmless
+    LiveKitSession::globalInitialize();
+    LiveKitSession::globalShutdown();
+    ST_ASSERT(true);
+}
+
+} // namespace
+
+int main()
+{
+    testFrameGeometry();
+    testTrackSelection();
+    testStateMachineHappyPath();
+    testPublisherSwapIsNotAnError();
+    testReconnect();
+    testFailureAndRecovery();
+
+    LiveKitSession::globalInitialize();
+    testConnectRejectsIncompleteConfig();
+    testConnectToUnreachableServerFailsCleanly();
+    testConnectToNonLiveKitServerFailsCleanly();
+    testDestroyWithoutDisconnect();
+    LiveKitSession::globalShutdown();
+
+    testGlobalInitIsReferenceCounted();
+
+    return st_test_report("session");
+}

core/tests/test_util.h

@@ -0,0 +1,91 @@
+/*
+streamer-tools OBS Camera Plugin - minimal test harness
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+#pragma once
+
+// Deliberately dependency-free (no gtest/catch2) so the core library's test
+// targets add no package-manager or network step to any of the three CI
+// platforms. Unlike bare assert(), this keeps running after a failure and
+// prints a real pass/fail count, so CI output says how much actually ran.
+
+#include <cstdio>
+#include <string>
+
+namespace st_test_detail {
+inline int &checks_run()
+{
+    static int n = 0;
+    return n;
+}
+inline int &checks_failed()
+{
+    static int n = 0;
+    return n;
+}
+inline std::string to_display(const std::string &v)
+{
+    return "\"" + v + "\"";
+}
+inline std::string to_display(const char *v)
+{
+    return v ? ("\"" + std::string(v) + "\"") : std::string("(null)");
+}
+inline std::string to_display(bool v)
+{
+    return v ? "true" : "false";
+}
+template<typename T> inline std::string to_display(const T &v)
+{
+    return std::to_string(v);
+}
+} // namespace st_test_detail
+
+#define ST_ASSERT(expr)                                                              \
+    do {                                                                             \
+        ++st_test_detail::checks_run();                                              \
+        if (!(expr)) {                                                               \
+            ++st_test_detail::checks_failed();                                       \
+            std::fprintf(stderr, "FAIL %s:%d: %s\n", __FILE__, __LINE__, #expr);     \
+        }                                                                            \
+    } while (0)
+
+#define ST_ASSERT_EQ(actual, expected)                                               \
+    do {                                                                             \
+        ++st_test_detail::checks_run();                                              \
+        auto _st_a = (actual);                                                       \
+        auto _st_e = (expected);                                                     \
+        if (!(_st_a == _st_e)) {                                                     \
+            ++st_test_detail::checks_failed();                                        \
+            std::fprintf(stderr, "FAIL %s:%d: %s\n  actual:   %s\n  expected: %s\n", \
+                         __FILE__, __LINE__, #actual " == " #expected,               \
+                         st_test_detail::to_display(_st_a).c_str(),                  \
+                         st_test_detail::to_display(_st_e).c_str());                 \
+        }                                                                            \
+    } while (0)
+
+inline int st_test_report(const char *suite)
+{
+    const int run = st_test_detail::checks_run();
+    const int failed = st_test_detail::checks_failed();
+    if (failed == 0) {
+        std::printf("%s: %d checks passed\n", suite, run);
+        return 0;
+    }
+    std::printf("%s: %d/%d checks FAILED\n", suite, failed, run);
+    return 1;
+}

obs-adapter/CMakeLists.txt

@@ -1,9 +1,8 @@
 # streamer-tools OBS Camera Plugin - OBS adapter
 #
-# Thin glue only, per the design doc: source registration, (eventually)
+# Thin glue only, per the design doc: source registration, the properties UI,
-# properties UI, and pushing frames into OBS. All real logic lives in
+# and pushing frames into OBS. All real logic lives in ../core. Only added to
-# ../core. Only added to the build when find_package(libobs) succeeds
+# the build when find_package(libobs) succeeds (see top-level CMakeLists.txt).
-# (see top-level CMakeLists.txt) -- see README.md for why.
 
 set(STPLUGIN_PROJECT_NAME "streamer-tools-camera")
 set(STPLUGIN_PROJECT_VERSION "${PROJECT_VERSION}")
@@ -15,7 +14,7 @@ configure_file(
 )
 
 add_library(${STPLUGIN_PROJECT_NAME} MODULE
-    src/plugin-main.c
+    src/plugin-main.cpp
     ${CMAKE_CURRENT_BINARY_DIR}/plugin-support.c
 )
 
@@ -35,3 +34,70 @@ set_target_properties(${STPLUGIN_PROJECT_NAME} PROPERTIES
     PREFIX ""
     OUTPUT_NAME ${STPLUGIN_PROJECT_NAME}
 )
+
+# The module has to find liblivekit / liblivekit_ffi next to itself once it is
+# installed into an OBS plugin directory, not at the build-tree path CMake's
+# default RPATH would bake in.
+# BUILD_WITH_INSTALL_RPATH is ON deliberately: the artifact that ships is a
+# straight copy of the built module (see the staging step below), so the
+# build-tree RPATH must never be baked in -- it would work on the build
+# machine and nowhere else.
+if(APPLE)
+    set_target_properties(${STPLUGIN_PROJECT_NAME} PROPERTIES
+        BUILD_WITH_INSTALL_RPATH ON
+        INSTALL_RPATH "@loader_path"
+    )
+elseif(UNIX)
+    set_target_properties(${STPLUGIN_PROJECT_NAME} PROPERTIES
+        BUILD_WITH_INSTALL_RPATH ON
+        INSTALL_RPATH "$ORIGIN"
+    )
+endif()
+
+# --- staged, runnable layout ------------------------------------------------
+# Everything a human needs to copy into an OBS plugin directory ends up under
+# build/package/, with the LiveKit shared libraries and the licence files
+# beside the module. Without this the module loads on the build machine only,
+# via the build-tree RPATH.
+set(STPLUGIN_PACKAGE_DIR "${CMAKE_BINARY_DIR}/package")
+
+# The binary subdirectory matches what OBS actually searches. From
+# AddExtraModulePaths() in obs-studio's UI/window-basic-main.cpp, the
+# per-user plugin layout on Linux and Windows is
+#   <config>/obs-studio/plugins/<name>/bin/64bit/<name>.{so,dll}
+#   <config>/obs-studio/plugins/<name>/data/
+# so staging into bin/64bit makes build/package/ a straight drop-in.
+#
+# macOS is NOT this shape -- there OBS looks for a
+# <name>.plugin/Contents/MacOS bundle -- and this build does not produce one.
+# See the macOS packaging gap in README.md; the flat bin/ here is honest
+# about being unfinished rather than pretending to be installable.
+if(APPLE)
+    set(STPLUGIN_PACKAGE_BIN_DIR "${STPLUGIN_PACKAGE_DIR}/bin")
+else()
+    set(STPLUGIN_PACKAGE_BIN_DIR "${STPLUGIN_PACKAGE_DIR}/bin/64bit")
+endif()
+
+add_custom_command(TARGET ${STPLUGIN_PROJECT_NAME} POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_BIN_DIR}"
+    COMMAND ${CMAKE_COMMAND} -E copy "$<TARGET_FILE:${STPLUGIN_PROJECT_NAME}>" "${STPLUGIN_PACKAGE_BIN_DIR}/"
+    COMMAND ${CMAKE_COMMAND} -E copy ${LIVEKIT_SDK_RUNTIME_LIBS} "${STPLUGIN_PACKAGE_BIN_DIR}/"
+    COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_DIR}/data/locale"
+    COMMAND ${CMAKE_COMMAND} -E copy
+        "${CMAKE_CURRENT_SOURCE_DIR}/data/locale/en-US.ini"
+        "${STPLUGIN_PACKAGE_DIR}/data/locale/"
+    # Redistributing LiveKit's prebuilt binaries means shipping their licence
+    # and notice with them. See third_party/livekit/README.md -- including
+    # what upstream does NOT ship, which is an open question, not a solved one.
+    COMMAND ${CMAKE_COMMAND} -E make_directory "${STPLUGIN_PACKAGE_DIR}/licenses/livekit"
+    COMMAND ${CMAKE_COMMAND} -E copy
+        "${CMAKE_SOURCE_DIR}/third_party/livekit/LICENSE"
+        "${CMAKE_SOURCE_DIR}/third_party/livekit/NOTICE"
+        "${CMAKE_SOURCE_DIR}/third_party/livekit/README.md"
+        "${STPLUGIN_PACKAGE_DIR}/licenses/livekit/"
+    COMMAND ${CMAKE_COMMAND} -E copy
+        "${CMAKE_SOURCE_DIR}/LICENSE"
+        "${STPLUGIN_PACKAGE_DIR}/licenses/"
+    COMMENT "Staging plugin + LiveKit runtime libraries + licences into ${STPLUGIN_PACKAGE_DIR}"
+    VERBATIM
+)

obs-adapter/data/locale/en-US.ini

@@ -1,2 +1,11 @@
-# streamer-tools OBS Camera Plugin - en-US locale
+StreamerToolsCamera="streamer-tools Camera"
-# No user-facing strings yet -- this is scaffolding (see plugin-main.c).
+ServerUrl="streamer-tools server URL"
+RoomSlug="Room"
+ReadKey="Read key"
+Camera="Camera"
+RefreshCameras="Refresh camera list"
+Status="Status"
+NoCameraSelected="(no camera selected)"
+OfflineSuffix=" (offline)"
+NotInRoomSuffix=" (not in this room)"
+CamerasFound=" cameras found"

obs-adapter/src/plugin-main.c

@@ -1,74 +0,0 @@
-/*
-streamer-tools OBS Camera Plugin
-Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
-
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License along
-with this program. If not, see <https://www.gnu.org/licenses/>
-*/
-
-/* SCAFFOLDING. This registers a source type so the OBS-adapter/core-
- * library split and OBS's module-loading toolchain can be proven end to
- * end, but it does not do anything real yet: no LiveKit FFI session, no
- * frames pushed via obs_source_output_video/audio, no properties UI.
- * See docs/superpowers/specs/2026-09-06-obs-camera-plugin-design.md in
- * the streamer-tools repo for what this becomes. */
-
-#include <obs-module.h>
-#include <util/bmem.h>
-#include <plugin-support.h>
-#include <stplugin/core_c.h>
-
-OBS_DECLARE_MODULE()
-OBS_MODULE_USE_DEFAULT_LOCALE(PLUGIN_NAME, "en-US")
-
-static const char *stcam_source_get_name(void *unused)
-{
-	UNUSED_PARAMETER(unused);
-	return "streamer-tools Camera (scaffold - not yet functional)";
-}
-
-static void *stcam_source_create(obs_data_t *settings, obs_source_t *source)
-{
-	UNUSED_PARAMETER(settings);
-	UNUSED_PARAMETER(source);
-	/* No LiveKit session, no state to speak of yet -- just proving the
-	 * source registers and OBS can instantiate/destroy it cleanly. */
-	return bzalloc(1);
-}
-
-static void stcam_source_destroy(void *data)
-{
-	bfree(data);
-}
-
-static struct obs_source_info streamer_tools_camera_source = {
-	.id = "streamer_tools_camera_source",
-	.type = OBS_SOURCE_TYPE_INPUT,
-	.output_flags = OBS_SOURCE_ASYNC_VIDEO,
-	.get_name = stcam_source_get_name,
-	.create = stcam_source_create,
-	.destroy = stcam_source_destroy,
-};
-
-bool obs_module_load(void)
-{
-	obs_log(LOG_INFO, "streamer-tools camera plugin scaffold loaded (core library version %s)",
-		stplugin_core_version());
-	obs_register_source(&streamer_tools_camera_source);
-	return true;
-}
-
-void obs_module_unload(void)
-{
-	obs_log(LOG_INFO, "streamer-tools camera plugin scaffold unloaded");
-}

obs-adapter/src/plugin-main.cpp

@@ -0,0 +1,605 @@
+/*
+streamer-tools OBS Camera Plugin
+Copyright (C) 2026 CyberCoveLLC <jknapp85@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program. If not, see <https://www.gnu.org/licenses/>
+*/
+
+// The thin glue layer, per the design doc: source registration, the
+// properties UI, and pushing frames into OBS. Everything that can be tested
+// headlessly lives in ../core.
+//
+// Two threading rules shape this whole file:
+//   - OBS calls create/update/destroy/get_properties on its UI or graphics
+//     thread. Nothing here may block them on the network, so every API call
+//     and every LiveKit connect happens on the source's own worker thread.
+//     The one exception is the explicit "Refresh camera list" button, where
+//     the operator asked for a round trip and is waiting for its result.
+//   - Frames arrive on LiveKitSession's reader threads. obs_source_output_video
+//     and obs_source_output_audio are safe to call from any thread, so they
+//     are called directly from there with no extra copy.
+
+#include <obs-module.h>
+#include <util/platform.h>
+
+#include <plugin-support.h>
+
+#include <stplugin/api_client.h>
+#include <stplugin/core.h>
+#include <stplugin/http.h>
+#include <stplugin/session.h>
+#include <stplugin/session_types.h>
+
+#include <livekit/logging.h>
+
+#include <atomic>
+#include <chrono>
+#include <condition_variable>
+#include <cstring>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <thread>
+#include <vector>
+
+using namespace stplugin;
+
+OBS_DECLARE_MODULE()
+OBS_MODULE_USE_DEFAULT_LOCALE(PLUGIN_NAME, "en-US")
+
+namespace {
+
+constexpr const char *kSettingServerUrl = "server_url";
+constexpr const char *kSettingRoomSlug = "room_slug";
+constexpr const char *kSettingReadKey = "read_key";
+constexpr const char *kSettingCamera = "camera";
+constexpr const char *kSettingStatus = "status";
+constexpr const char *kPropRefresh = "refresh";
+
+/// Shorter than the core default: this one runs while an operator is staring
+/// at a properties dialog they pressed a button in.
+constexpr int kPropertiesTimeoutMs = 5000;
+
+/// Reconnect backoff bounds. A dark room or a stopped server must not turn
+/// into a request storm, but a transient blip should recover quickly.
+constexpr int kBackoffStartMs = 1000;
+constexpr int kBackoffMaxMs = 30000;
+
+std::string settingString(obs_data_t *settings, const char *key)
+{
+    const char *value = obs_data_get_string(settings, key);
+    return value ? std::string(value) : std::string();
+}
+
+video_format toObsVideoFormat(PixelFormat format)
+{
+    switch (format) {
+    case PixelFormat::I420: return VIDEO_FORMAT_I420;
+    case PixelFormat::NV12: return VIDEO_FORMAT_NV12;
+    case PixelFormat::BGRA: return VIDEO_FORMAT_BGRA;
+    }
+    return VIDEO_FORMAT_I420;
+}
+
+// ---------------------------------------------------------------------------
+// Source instance
+// ---------------------------------------------------------------------------
+
+struct CameraSource {
+    obs_source_t *source = nullptr;
+
+    // --- configuration, guarded by `mutex` ---
+    std::mutex mutex;
+    ConnectionConfig config;
+    std::string camera_identity;
+    /// Bumped every time settings change; the worker compares it to what it
+    /// last connected with, so a stale in-flight connect is abandoned rather
+    /// than fought over.
+    std::uint64_t generation = 0;
+    std::vector<SlotInfo> slot_cache;
+    std::string status_text = "not configured";
+
+    // --- worker ---
+    std::thread worker;
+    std::condition_variable wake;
+    std::atomic<bool> stopping{false};
+
+    std::shared_ptr<ApiClient> api;
+    std::unique_ptr<LiveKitSession> session;
+
+    std::atomic<std::uint64_t> frames_out{0};
+    /// width<<16 | height of the last frame pushed, so a geometry change can
+    /// be logged exactly once.
+    std::atomic<std::uint32_t> last_geometry{0};
+    /// Whether the current status line is a problem the operator must act on
+    /// (a wrong read key), rather than ordinary progress.
+    std::atomic<bool> status_is_error{false};
+
+    void setStatus(std::string text)
+    {
+        std::lock_guard<std::mutex> guard(mutex);
+        status_text = std::move(text);
+    }
+
+    std::string statusText()
+    {
+        std::lock_guard<std::mutex> guard(mutex);
+        return status_text;
+    }
+};
+
+// ---------------------------------------------------------------------------
+// Frame output
+// ---------------------------------------------------------------------------
+
+void outputVideoFrame(CameraSource *self, const VideoFrameData &frame)
+{
+    obs_source_frame out = {};
+    out.width = static_cast<std::uint32_t>(frame.width);
+    out.height = static_cast<std::uint32_t>(frame.height);
+    out.format = toObsVideoFormat(frame.format);
+
+    // Both video and audio are stamped with the SAME clock (os_gettime_ns at
+    // arrival) rather than video using WebRTC's timestamp_us and audio using
+    // arrival time. The SDK's VideoFrameCallback carries a capture-time
+    // timestamp but its AudioFrameCallback carries none, and mixing two
+    // epochs inside one OBS source is a guaranteed A/V drift. This relies on
+    // the SDK's jitter buffering having already aligned the two -- the
+    // assumption the design doc flags for verification on real hardware.
+    out.timestamp = os_gettime_ns();
+
+    for (int i = 0; i < frame.plane_count && i < MAX_AV_PLANES; ++i) {
+        out.data[i] = const_cast<std::uint8_t *>(frame.planes[i].data);
+        out.linesize[i] = frame.planes[i].stride;
+    }
+
+    // WebRTC delivers limited-range BT.709 for anything at or above SD.
+    //
+    // The plain video_format_get_parameters, not the _for_format variant:
+    // the latter only exists from libobs 30 onwards, and it only differs for
+    // the 10-bit formats (I010/P010) this source never receives. Using the
+    // older entry point keeps the module loadable on an older OBS, which is
+    // the direction that matters -- OBS refuses modules built against a
+    // NEWER libobs than the one running.
+    video_format_get_parameters(VIDEO_CS_709, VIDEO_RANGE_PARTIAL, out.color_matrix, out.color_range_min,
+                                out.color_range_max);
+    out.full_range = false;
+
+    obs_source_output_video(self->source, &out);
+    self->frames_out.fetch_add(1);
+
+    // Log the first frame, and any later change of geometry. A director's
+    // log then answers "did video ever arrive, and at what size" without
+    // anyone having to reproduce the problem -- and WebRTC really does
+    // change resolution mid-stream as it ramps a subscription up.
+    const std::uint32_t geometry = out.width << 16 | out.height;
+    const std::uint32_t previous = self->last_geometry.exchange(geometry);
+    if (previous != geometry)
+        obs_log(LOG_INFO, "video frame %ux%u %s", out.width, out.height, describePixelFormat(frame.format));
+}
+
+void outputAudioFrame(CameraSource *self, const AudioFrameData &frame)
+{
+    if (!frame.samples || frame.samples_per_channel <= 0)
+        return;
+
+    obs_source_audio out = {};
+    out.data[0] = reinterpret_cast<const std::uint8_t *>(frame.samples);
+    out.frames = static_cast<std::uint32_t>(frame.samples_per_channel);
+    out.format = AUDIO_FORMAT_16BIT; // interleaved int16, which is what the SDK hands us
+    out.samples_per_sec = static_cast<std::uint32_t>(frame.sample_rate);
+    out.timestamp = os_gettime_ns();
+
+    switch (frame.channels) {
+    case 1: out.speakers = SPEAKERS_MONO; break;
+    case 2: out.speakers = SPEAKERS_STEREO; break;
+    default:
+        // Anything else would need a channel-map decision we have no reason
+        // to guess at; a streamer-tools mic is mono or stereo.
+        return;
+    }
+
+    obs_source_output_audio(self->source, &out);
+}
+
+// ---------------------------------------------------------------------------
+// Worker: mint a token, connect, keep it connected
+// ---------------------------------------------------------------------------
+
+void workerLoop(CameraSource *self)
+{
+    std::uint64_t connected_generation = 0;
+    bool connected = false;
+    int backoff_ms = kBackoffStartMs;
+
+    for (;;) {
+        ConnectionConfig config;
+        std::string camera;
+        std::uint64_t generation = 0;
+        {
+            std::unique_lock<std::mutex> lock(self->mutex);
+            if (self->stopping.load())
+                break;
+            config = self->config;
+            camera = self->camera_identity;
+            generation = self->generation;
+        }
+
+        const bool config_changed = generation != connected_generation;
+        if (config_changed) {
+            // A settings change is an operator action: try again immediately,
+            // whatever the previous attempt's backoff had grown to.
+            backoff_ms = kBackoffStartMs;
+        }
+        const bool needs_connect =
+            !connected || config_changed ||
+            (self->session && (self->session->state() == SessionState::Failed ||
+                               self->session->state() == SessionState::Disconnected));
+
+        if (needs_connect) {
+            if (connected || config_changed) {
+                if (self->session)
+                    self->session->disconnect();
+                obs_source_output_video(self->source, nullptr);
+                connected = false;
+            }
+
+            if (!config.is_valid() || camera.empty()) {
+                self->setStatus("not configured -- set the server URL, room, read key and camera");
+                connected_generation = generation;
+                // Back off like any other unsuccessful attempt, so an
+                // unconfigured source is not a once-a-second no-op forever.
+                // Filling the settings in bumps the generation and wakes this
+                // thread immediately, so the backoff costs no responsiveness.
+                backoff_ms = backoff_ms * 2 < kBackoffMaxMs ? backoff_ms * 2 : kBackoffMaxMs;
+            } else {
+                self->setStatus("connecting...");
+                const TokenResult token = self->api->requestToken(config);
+                if (!token.ok()) {
+                    // token.message is the specific one ("the read key is
+                    // wrong or has been rotated"); describeApiStatus is the
+                    // generic fallback. Printing both just reads as noise.
+                    const std::string message =
+                        token.message.empty() ? describeApiStatus(token.status) : token.message;
+                    self->setStatus(message);
+                    self->status_is_error.store(true);
+                    obs_log(LOG_WARNING, "token request failed: %s", message.c_str());
+                } else {
+                    // Refresh the dropdown cache while we are here; the
+                    // properties UI then opens instantly instead of blocking
+                    // on the network.
+                    const SlotsResult slots = self->api->fetchSlots(config);
+                    if (slots.ok()) {
+                        std::lock_guard<std::mutex> guard(self->mutex);
+                        self->slot_cache = slots.slots;
+                    }
+
+                    SessionConfig session_config;
+                    session_config.ws_url = token.ws_url;
+                    session_config.token = token.lk_token;
+                    session_config.participant_identity = camera;
+
+                    if (self->session->connect(session_config)) {
+                        connected = true;
+                        connected_generation = generation;
+                        backoff_ms = kBackoffStartMs;
+                        self->status_is_error.store(false);
+                        obs_log(LOG_INFO, "connected to %s as %s, watching %s", token.ws_url.c_str(),
+                                token.identity.c_str(), camera.c_str());
+                    } else {
+                        self->setStatus(self->session->stateDetail());
+                    }
+                }
+
+                if (!connected) {
+                    backoff_ms = backoff_ms * 2 < kBackoffMaxMs ? backoff_ms * 2 : kBackoffMaxMs;
+                    connected_generation = generation;
+                }
+            }
+        }
+
+        // Poll rather than push: the state handler could notify us, but it
+        // runs on a LiveKit thread and this keeps the wake-up path single.
+        std::unique_lock<std::mutex> lock(self->mutex);
+        self->wake.wait_for(lock, std::chrono::milliseconds(connected ? 1000 : backoff_ms),
+                            [self, generation] { return self->stopping.load() || self->generation != generation; });
+        if (self->stopping.load())
+            break;
+    }
+
+    if (self->session)
+        self->session->disconnect();
+}
+
+// ---------------------------------------------------------------------------
+// obs_source_info callbacks
+// ---------------------------------------------------------------------------
+
+const char *sourceGetName(void *)
+{
+    return obs_module_text("StreamerToolsCamera");
+}
+
+void sourceGetDefaults(obs_data_t *settings)
+{
+    obs_data_set_default_string(settings, kSettingServerUrl, "");
+    obs_data_set_default_string(settings, kSettingRoomSlug, "");
+    obs_data_set_default_string(settings, kSettingReadKey, "");
+    obs_data_set_default_string(settings, kSettingCamera, "");
+}
+
+void applySettings(CameraSource *self, obs_data_t *settings)
+{
+    ConnectionConfig config;
+    config.server_url = settingString(settings, kSettingServerUrl);
+    config.room_slug = settingString(settings, kSettingRoomSlug);
+    config.read_key = settingString(settings, kSettingReadKey);
+    const std::string camera = settingString(settings, kSettingCamera);
+
+    {
+        std::lock_guard<std::mutex> guard(self->mutex);
+        const bool changed = config.server_url != self->config.server_url ||
+                             config.room_slug != self->config.room_slug ||
+                             config.read_key != self->config.read_key || camera != self->camera_identity;
+        if (!changed)
+            return;
+        self->config = config;
+        self->camera_identity = camera;
+        ++self->generation;
+    }
+    self->wake.notify_all();
+}
+
+void *sourceCreate(obs_data_t *settings, obs_source_t *source)
+{
+    auto *self = new CameraSource();
+    self->source = source;
+    self->api = std::make_shared<ApiClient>(std::shared_ptr<HttpClient>(createPlatformHttpClient()));
+    self->session = std::unique_ptr<LiveKitSession>(new LiveKitSession());
+
+    self->session->setVideoHandler([self](const VideoFrameData &frame) { outputVideoFrame(self, frame); });
+    self->session->setAudioHandler([self](const AudioFrameData &frame) { outputAudioFrame(self, frame); });
+    self->session->setStateHandler([self](SessionState state, const std::string &detail) {
+        self->setStatus(detail.empty() ? describeSessionState(state) : detail);
+        self->status_is_error.store(state == SessionState::Failed);
+
+        // A camera that stopped publishing must not leave its last frame on
+        // screen -- that is precisely the stale-media failure this plugin
+        // exists to avoid. A null frame clears the source.
+        if (state != SessionState::Connected) {
+            obs_source_output_video(self->source, nullptr);
+            // Forget the last geometry so the next stream logs its first
+            // frame again; otherwise a reconnect at the same resolution is
+            // silent, and the log stops answering "did video come back".
+            self->last_geometry.store(0);
+        }
+    });
+
+    {
+        std::lock_guard<std::mutex> guard(self->mutex);
+        self->config.server_url = settingString(settings, kSettingServerUrl);
+        self->config.room_slug = settingString(settings, kSettingRoomSlug);
+        self->config.read_key = settingString(settings, kSettingReadKey);
+        self->camera_identity = settingString(settings, kSettingCamera);
+        self->generation = 1;
+    }
+
+    self->worker = std::thread([self] { workerLoop(self); });
+    return self;
+}
+
+void sourceUpdate(void *data, obs_data_t *settings)
+{
+    applySettings(static_cast<CameraSource *>(data), settings);
+}
+
+void sourceDestroy(void *data)
+{
+    auto *self = static_cast<CameraSource *>(data);
+    if (!self)
+        return;
+
+    {
+        // Must be set while holding `mutex`, matching how `generation` is
+        // mutated in applySettings: the worker's wait predicate reads
+        // `stopping` under this same lock, so setting it outside the lock
+        // can race between the worker's predicate check and it entering
+        // the wait, dropping the notify_all() below and leaving the worker
+        // asleep for its full backoff (up to kBackoffMaxMs) while this
+        // (OBS UI) thread blocks in worker.join().
+        std::lock_guard<std::mutex> guard(self->mutex);
+        self->stopping.store(true);
+    }
+    self->wake.notify_all();
+    if (self->worker.joinable())
+        self->worker.join();
+
+    // The worker already disconnected, but do it again explicitly: the
+    // session's own destructor would too, and all three are idempotent.
+    if (self->session)
+        self->session->disconnect();
+    self->session.reset();
+
+    delete self;
+}
+
+/// Rebuild the camera dropdown from the cached slot list, always including
+/// whatever identity is currently selected so OBS cannot silently clear a
+/// setting just because the room is dark right now.
+void populateCameraList(CameraSource *self, obs_property_t *list, const std::string &selected)
+{
+    obs_property_list_clear(list);
+    obs_property_list_add_string(list, obs_module_text("NoCameraSelected"), "");
+
+    bool saw_selected = selected.empty();
+    std::vector<SlotInfo> slots;
+    {
+        std::lock_guard<std::mutex> guard(self->mutex);
+        slots = self->slot_cache;
+    }
+    for (const SlotInfo &slot : slots) {
+        std::string label = slot.display_name;
+        if (!slot.live)
+            label += obs_module_text("OfflineSuffix");
+        obs_property_list_add_string(list, label.c_str(), slot.identity.c_str());
+        if (slot.identity == selected)
+            saw_selected = true;
+    }
+    if (!saw_selected) {
+        std::string label = selected + obs_module_text("NotInRoomSuffix");
+        obs_property_list_add_string(list, label.c_str(), selected.c_str());
+    }
+}
+
+bool refreshButtonClicked(obs_properties_t *props, obs_property_t *, void *data)
+{
+    auto *self = static_cast<CameraSource *>(data);
+    if (!self)
+        return false;
+
+    ConnectionConfig config;
+    {
+        std::lock_guard<std::mutex> guard(self->mutex);
+        config = self->config;
+    }
+
+    // Deliberately synchronous: the operator pressed a button and is waiting
+    // for the list to change. The timeout is shortened from the core default
+    // so a dead server cannot freeze the properties dialog for ten seconds.
+    const SlotsResult result = self->api->fetchSlots(config, kPropertiesTimeoutMs);
+
+    if (result.ok()) {
+        std::string selected;
+        {
+            std::lock_guard<std::mutex> guard(self->mutex);
+            self->slot_cache = result.slots;
+            selected = self->camera_identity;
+        }
+        if (obs_property_t *list = obs_properties_get(props, kSettingCamera))
+            populateCameraList(self, list, selected);
+        self->setStatus(std::to_string(result.slots.size()) + std::string(obs_module_text("CamerasFound")));
+        self->status_is_error.store(false);
+    } else {
+        const std::string message = result.message.empty() ? describeApiStatus(result.status) : result.message;
+        self->setStatus(message);
+        self->status_is_error.store(true);
+        obs_log(LOG_WARNING, "slot listing failed: %s", message.c_str());
+    }
+
+    if (obs_property_t *status = obs_properties_get(props, kSettingStatus)) {
+        const std::string text = self->statusText();
+        obs_property_set_description(status, text.c_str());
+        obs_property_text_set_info_type(status, self->status_is_error.load() ? OBS_TEXT_INFO_WARNING
+                                                                            : OBS_TEXT_INFO_NORMAL);
+    }
+
+    return true; // properties changed, redraw them
+}
+
+obs_properties_t *sourceGetProperties(void *data)
+{
+    auto *self = static_cast<CameraSource *>(data);
+    obs_properties_t *props = obs_properties_create();
+
+    obs_properties_add_text(props, kSettingServerUrl, obs_module_text("ServerUrl"), OBS_TEXT_DEFAULT);
+    obs_properties_add_text(props, kSettingRoomSlug, obs_module_text("RoomSlug"), OBS_TEXT_DEFAULT);
+    // The read key is a credential and is masked everywhere else in
+    // streamer-tools; it is masked here too.
+    obs_properties_add_text(props, kSettingReadKey, obs_module_text("ReadKey"), OBS_TEXT_PASSWORD);
+
+    obs_property_t *list = obs_properties_add_list(props, kSettingCamera, obs_module_text("Camera"),
+                                                   OBS_COMBO_TYPE_LIST, OBS_COMBO_FORMAT_STRING);
+    if (self) {
+        std::string selected;
+        {
+            std::lock_guard<std::mutex> guard(self->mutex);
+            selected = self->camera_identity;
+        }
+        // Built from the cache the worker keeps warm, so opening properties
+        // never blocks on the network. The button below is the way to force
+        // a round trip.
+        populateCameraList(self, list, selected);
+    }
+
+    obs_properties_add_button(props, kPropRefresh, obs_module_text("RefreshCameras"), refreshButtonClicked);
+
+    // An OBS_TEXT_INFO property renders its *description* as the visible
+    // label, so the status line goes there rather than into a tooltip an
+    // operator would never hover over mid-show.
+    const std::string status_text = self ? self->statusText() : std::string(obs_module_text("Status"));
+    obs_property_t *status = obs_properties_add_text(props, kSettingStatus, status_text.c_str(), OBS_TEXT_INFO);
+    if (self && self->status_is_error.load())
+        obs_property_text_set_info_type(status, OBS_TEXT_INFO_WARNING);
+
+    return props;
+}
+
+struct obs_source_info cameraSourceInfo()
+{
+    struct obs_source_info info = {};
+    info.id = "streamer_tools_camera_source";
+    info.type = OBS_SOURCE_TYPE_INPUT;
+    info.output_flags = OBS_SOURCE_ASYNC_VIDEO | OBS_SOURCE_AUDIO | OBS_SOURCE_DO_NOT_DUPLICATE;
+    info.icon_type = OBS_ICON_TYPE_CAMERA;
+    info.get_name = sourceGetName;
+    info.create = sourceCreate;
+    info.destroy = sourceDestroy;
+    info.update = sourceUpdate;
+    info.get_defaults = sourceGetDefaults;
+    info.get_properties = sourceGetProperties;
+    return info;
+}
+
+struct obs_source_info streamer_tools_camera_source = cameraSourceInfo();
+
+void livekitLogToObs(livekit::LogLevel level, const std::string &, const std::string &message)
+{
+    int obs_level = LOG_INFO;
+    switch (level) {
+    case livekit::LogLevel::Error:
+    case livekit::LogLevel::Critical: obs_level = LOG_ERROR; break;
+    case livekit::LogLevel::Warn: obs_level = LOG_WARNING; break;
+    case livekit::LogLevel::Info: obs_level = LOG_INFO; break;
+    default: obs_level = LOG_DEBUG; break;
+    }
+    // LiveKit's signaling connection URL carries the access token as a
+    // query parameter. This is defensive, not a response to a confirmed
+    // leak: if the SDK ever logs that URL (or anything else carrying
+    // "access_token=" or "key="), the token must not land verbatim in an
+    // OBS log file that a director might paste into a support ticket. Scrub
+    // unconditionally before this message ever reaches obs_log.
+    const std::string scrubbed = ApiClient::redactSensitiveParams(message);
+    obs_log(obs_level, "livekit: %s", scrubbed.c_str());
+}
+
+} // namespace
+
+bool obs_module_load(void)
+{
+    LiveKitSession::globalInitialize();
+    // Route the SDK's own logging into OBS's log file instead of stderr,
+    // where a director would never see it.
+    livekit::setLogCallback(livekitLogToObs);
+
+    obs_register_source(&streamer_tools_camera_source);
+    obs_log(LOG_INFO, "streamer-tools camera plugin loaded (core %s)", core_version());
+    return true;
+}
+
+void obs_module_unload(void)
+{
+    livekit::setLogCallback(nullptr);
+    LiveKitSession::globalShutdown();
+    obs_log(LOG_INFO, "streamer-tools camera plugin unloaded");
+}

scripts/livekit-dev-room.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+"""Mint LiveKit JWTs for the integration test against a local dev server.
+
+Usage:
+    livekit-server --dev --bind 127.0.0.1 &
+    eval "$(python3 scripts/livekit-dev-room.py)"
+    ctest --test-dir build -R test_integration_livekit --output-on-failure
+
+Prints shell `export` lines for the four STPLUGIN_IT_* variables
+core/tests/test_integration_livekit.cpp looks for. With no arguments it uses
+`livekit-server --dev`'s built-in devkey/secret credentials.
+
+Standard library only (hmac + hashlib + base64) -- there is deliberately no
+pip install step here, so this runs anywhere the repo is checked out.
+"""
+
+import argparse
+import base64
+import hashlib
+import hmac
+import json
+import os
+import time
+
+
+def b64url(raw: bytes) -> str:
+    return base64.urlsafe_b64encode(raw).rstrip(b"=").decode("ascii")
+
+
+def mint(api_key: str, api_secret: str, identity: str, room: str, *, publish: bool, subscribe: bool) -> str:
+    now = int(time.time())
+    header = {"alg": "HS256", "typ": "JWT"}
+    claims = {
+        "iss": api_key,
+        "sub": identity,
+        "name": identity,
+        "nbf": now - 10,
+        "exp": now + 3600,
+        "video": {
+            "room": room,
+            "roomJoin": True,
+            "canPublish": publish,
+            "canSubscribe": subscribe,
+            "canPublishData": False,
+        },
+    }
+    signing_input = f"{b64url(json.dumps(header, separators=(',', ':')).encode())}." \
+                    f"{b64url(json.dumps(claims, separators=(',', ':')).encode())}"
+    signature = hmac.new(api_secret.encode(), signing_input.encode(), hashlib.sha256).digest()
+    return f"{signing_input}.{b64url(signature)}"
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--url", default=os.environ.get("LIVEKIT_URL", "ws://127.0.0.1:7880"))
+    parser.add_argument("--api-key", default=os.environ.get("LIVEKIT_API_KEY", "devkey"))
+    parser.add_argument("--api-secret", default=os.environ.get("LIVEKIT_API_SECRET", "secret"))
+    parser.add_argument("--room", default="obs-plugin-it")
+    parser.add_argument("--publisher-identity", default="cam-test")
+    parser.add_argument("--subscriber-identity", default="obs:obs-plugin-it:test")
+    args = parser.parse_args()
+
+    publish_token = mint(args.api_key, args.api_secret, args.publisher_identity, args.room,
+                         publish=True, subscribe=False)
+    # Deliberately the same grant shape the real server mints for the plugin
+    # (apps/server/src/obs/plugin.routes.ts -> mintCaptionsToken): subscribe
+    # only, never publish.
+    subscribe_token = mint(args.api_key, args.api_secret, args.subscriber_identity, args.room,
+                           publish=False, subscribe=True)
+
+    print(f'export STPLUGIN_IT_URL="{args.url}"')
+    print(f'export STPLUGIN_IT_PUBLISH_TOKEN="{publish_token}"')
+    print(f'export STPLUGIN_IT_SUBSCRIBE_TOKEN="{subscribe_token}"')
+    print(f'export STPLUGIN_IT_PUBLISHER_IDENTITY="{args.publisher_identity}"')
+
+
+if __name__ == "__main__":
+    main()

third_party/livekit/LICENSE

@@ -0,0 +1,175 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
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+      transformation or translation of a Source form, including but
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+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
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+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
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+
+   9. Accepting Warranty or Additional Liability. While redistributing
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+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.

third_party/livekit/NOTICE

@@ -0,0 +1,13 @@
+Copyright 2023 LiveKit, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

third_party/livekit/README.md

@@ -0,0 +1,36 @@
+# LiveKit client-sdk-cpp redistribution notices
+
+This plugin links and **redistributes** prebuilt binaries from
+[`livekit/client-sdk-cpp`](https://github.com/livekit/client-sdk-cpp) — the
+`liblivekit` / `liblivekit_ffi` shared libraries that ship next to the plugin
+module — so the SDK's licence and notice files ship with it.
+
+`LICENSE` and `NOTICE` here are copied verbatim from the pinned release tag
+`v1.10.1` (Apache License 2.0). They are staged into `build/package/licenses/`
+by `obs-adapter/CMakeLists.txt` on every build, alongside this plugin's own
+GPL-2.0 `LICENSE`.
+
+## A correction to the design doc
+
+The design doc's open questions say:
+
+> `client-sdk-cpp`'s bundled `LICENSE.md` (~28 distinct third-party license
+> blocks — Google WebRTC, OpenH264, etc.) must ship inside the plugin package
+
+**No such file exists at `v1.10.1`.** Checked, on 2026-09-06:
+
+- The five release archives for this tag (`livekit-sdk-<triple>-1.10.1.tar.gz`
+  / `.zip`) contain only `include/`, `lib/`, `bin/` and
+  `share/livekit/build-info.json`. No licence file of any kind.
+- The repository at tag `v1.10.1` has `LICENSE` (Apache-2.0, 10142 bytes) and
+  `NOTICE` (553 bytes) at its root. There is no `LICENSE.md`, no `NOTICE.md`,
+  and no `THIRD_PARTY_LICENSES` file.
+
+So what ships here is the Apache-2.0 licence and notice, which is what
+actually exists upstream. **The aggregated third-party notice the design doc
+expected — covering the WebRTC/OpenH264/etc. code statically linked inside
+`liblivekit_ffi.so` — has not been located and is not being shipped.** That
+is a real, open licensing question for whoever signs off on distributing
+release binaries, not something this packaging step has resolved. Worth
+raising upstream, or asking counsel whether the Apache-2.0 NOTICE alone
+suffices for a binary redistribution of that library.