Download sidecar on first launch instead of bundling

Major refactor: sidecar is no longer bundled in the installer. Instead,
it's downloaded on first launch with a setup screen offering CPU vs CUDA
choice. This solves the 2GB+ installer size limit and decouples app/sidecar.

Backend:
- New commands: check_sidecar, download_sidecar, check_sidecar_update
- Streaming download with progress events via reqwest
- Added reqwest + futures-util dependencies
- Removed sidecar.zip from bundle resources
- Restored NSIS target (no longer size-constrained)

CI:
- Each platform builds both CPU and CUDA sidecar variants (except macOS: CPU only)
- Sidecar zips uploaded as separate release assets
- Asset naming: sidecar-{os}-{arch}-{variant}.zip

Frontend:
- SidecarSetup.svelte: first-launch setup with CPU/CUDA radio choice,
  progress bar, error/retry handling
- Update banner on launch if newer sidecar version available
- Conditional rendering: setup screen → main app flow

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -112,13 +112,23 @@ jobs:
       - name: Set up Python
         run: uv python install ${{ env.PYTHON_VERSION }}
 
-      - name: Build sidecar
+      - name: Build sidecar (CUDA)
         working-directory: python
         run: uv run --python ${{ env.PYTHON_VERSION }} python build_sidecar.py --with-cuda
 
-      - name: Package sidecar for Tauri
+      - name: Package sidecar (CUDA)
         run: |
-          cd python/dist/voice-to-notes-sidecar && zip -r ../../../src-tauri/sidecar.zip .
+          cd python/dist/voice-to-notes-sidecar && zip -r ../../../sidecar-linux-x86_64-cuda.zip .
+
+      - name: Build sidecar (CPU)
+        working-directory: python
+        run: |
+          rm -rf dist/voice-to-notes-sidecar
+          uv run --python ${{ env.PYTHON_VERSION }} python build_sidecar.py --cpu-only
+
+      - name: Package sidecar (CPU)
+        run: |
+          cd python/dist/voice-to-notes-sidecar && zip -r ../../../sidecar-linux-x86_64-cpu.zip .
 
       # ── Tauri app ──
       - name: Set up Node.js
@@ -183,6 +193,26 @@ jobs:
             echo "Upload response: HTTP ${HTTP_CODE}"
           done
 
+          for file in sidecar-*.zip; do
+            filename=$(basename "$file")
+            encoded_name=$(echo "$filename" | sed 's/ /%20/g')
+            echo "Uploading ${filename} ($(du -h "$file" | cut -f1))..."
+
+            ASSET_ID=$(curl -s -H "Authorization: token ${BUILD_TOKEN}" \
+              "${REPO_API}/releases/${RELEASE_ID}/assets" | jq -r ".[] | select(.name == \"${filename}\") | .id // empty")
+            if [ -n "${ASSET_ID}" ]; then
+              curl -s -X DELETE -H "Authorization: token ${BUILD_TOKEN}" \
+                "${REPO_API}/releases/${RELEASE_ID}/assets/${ASSET_ID}"
+            fi
+
+            HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" -X POST \
+              -H "Authorization: token ${BUILD_TOKEN}" \
+              -H "Content-Type: application/octet-stream" \
+              -T "$file" \
+              "${REPO_API}/releases/${RELEASE_ID}/assets?name=${encoded_name}")
+            echo "Upload response: HTTP ${HTTP_CODE}"
+          done
+
   build-windows:
     name: Build (Windows)
     needs: bump-version
@@ -214,19 +244,34 @@ jobs:
         shell: powershell
         run: uv python install ${{ env.PYTHON_VERSION }}
 
-      - name: Build sidecar
+      - name: Install 7-Zip
+        shell: powershell
+        run: |
+          if (-not (Get-Command 7z -ErrorAction SilentlyContinue)) {
+            choco install 7zip -y
+          }
+
+      - name: Build sidecar (CUDA)
         shell: powershell
         working-directory: python
         run: uv run --python ${{ env.PYTHON_VERSION }} python build_sidecar.py --with-cuda
 
-      - name: Package sidecar for Tauri
+      - name: Package sidecar (CUDA)
         shell: powershell
         run: |
-          # Compress-Archive has a 2GB limit; use 7z for CUDA builds
-          if (-not (Get-Command 7z -ErrorAction SilentlyContinue)) {
-            choco install 7zip -y
-          }
-          7z a -tzip -mx=5 src-tauri\sidecar.zip .\python\dist\voice-to-notes-sidecar\*
+          7z a -tzip -mx=5 sidecar-windows-x86_64-cuda.zip .\python\dist\voice-to-notes-sidecar\*
+
+      - name: Build sidecar (CPU)
+        shell: powershell
+        working-directory: python
+        run: |
+          Remove-Item -Recurse -Force dist\voice-to-notes-sidecar
+          uv run --python ${{ env.PYTHON_VERSION }} python build_sidecar.py --cpu-only
+
+      - name: Package sidecar (CPU)
+        shell: powershell
+        run: |
+          7z a -tzip -mx=5 sidecar-windows-x86_64-cpu.zip .\python\dist\voice-to-notes-sidecar\*
 
       # ── Tauri app ──
       - name: Set up Node.js
@@ -299,6 +344,34 @@ jobs:
             }
           }
 
+          Get-ChildItem -Path . -Filter "sidecar-*.zip" | ForEach-Object {
+            $filename = $_.Name
+            $encodedName = [System.Uri]::EscapeDataString($filename)
+            $size = [math]::Round($_.Length / 1MB, 1)
+            Write-Host "Uploading ${filename} (${size} MB)..."
+
+            try {
+              $assets = Invoke-RestMethod -Uri "${REPO_API}/releases/${RELEASE_ID}/assets" -Headers $Headers
+              $existing = $assets | Where-Object { $_.name -eq $filename }
+              if ($existing) {
+                Invoke-RestMethod -Uri "${REPO_API}/releases/${RELEASE_ID}/assets/$($existing.id)" -Method Delete -Headers $Headers
+              }
+            } catch {}
+
+            $uploadUrl = "${REPO_API}/releases/${RELEASE_ID}/assets?name=${encodedName}"
+            $result = curl.exe --fail --silent --show-error `
+              -X POST `
+              -H "Authorization: token $env:BUILD_TOKEN" `
+              -H "Content-Type: application/octet-stream" `
+              -T "$($_.FullName)" `
+              "$uploadUrl" 2>&1
+            if ($LASTEXITCODE -eq 0) {
+              Write-Host "Upload successful: ${filename}"
+            } else {
+              Write-Host "WARNING: Upload failed for ${filename}: ${result}"
+            }
+          }
+
   build-macos:
     name: Build (macOS)
     needs: bump-version
@@ -327,13 +400,13 @@ jobs:
       - name: Set up Python
         run: uv python install ${{ env.PYTHON_VERSION }}
 
-      - name: Build sidecar
+      - name: Build sidecar (CPU)
         working-directory: python
         run: uv run --python ${{ env.PYTHON_VERSION }} python build_sidecar.py --cpu-only
 
-      - name: Package sidecar for Tauri
+      - name: Package sidecar (CPU)
         run: |
-          cd python/dist/voice-to-notes-sidecar && zip -r ../../../src-tauri/sidecar.zip .
+          cd python/dist/voice-to-notes-sidecar && zip -r ../../../sidecar-macos-aarch64-cpu.zip .
 
       # ── Tauri app ──
       - name: Set up Node.js
@@ -397,3 +470,23 @@ jobs:
               "${REPO_API}/releases/${RELEASE_ID}/assets?name=${encoded_name}")
             echo "Upload response: HTTP ${HTTP_CODE}"
           done
+
+          for file in sidecar-*.zip; do
+            filename=$(basename "$file")
+            encoded_name=$(echo "$filename" | sed 's/ /%20/g')
+            echo "Uploading ${filename} ($(du -h "$file" | cut -f1))..."
+
+            ASSET_ID=$(curl -s -H "Authorization: token ${BUILD_TOKEN}" \
+              "${REPO_API}/releases/${RELEASE_ID}/assets" | jq -r ".[] | select(.name == \"${filename}\") | .id // empty")
+            if [ -n "${ASSET_ID}" ]; then
+              curl -s -X DELETE -H "Authorization: token ${BUILD_TOKEN}" \
+                "${REPO_API}/releases/${RELEASE_ID}/assets/${ASSET_ID}"
+            fi
+
+            HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" -X POST \
+              -H "Authorization: token ${BUILD_TOKEN}" \
+              -H "Content-Type: application/octet-stream" \
+              -T "$file" \
+              "${REPO_API}/releases/${RELEASE_ID}/assets?name=${encoded_name}")
+            echo "Upload response: HTTP ${HTTP_CODE}"
+          done

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "voice-to-notes",
-  "version": "0.1.0",
+  "version": "0.2.10",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "voice-to-notes",
-      "version": "0.1.0",
+      "version": "0.2.10",
       "license": "MIT",
       "dependencies": {
         "@tauri-apps/api": "^2",

src-tauri/Cargo.lock

@@ -59,6 +59,15 @@ version = "1.0.102"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 
+[[package]]
+name = "arbitrary"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d036a3c4ab069c7b410a2ce876bd74808d2d0888a82667669f8e783a898bf1"
+dependencies = [
+ "derive_arbitrary",
+]
+
 [[package]]
 name = "async-broadcast"
 version = "0.7.2"
@@ -655,6 +664,17 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "derive_arbitrary"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e567bd82dcff979e4b03460c307b3cdc9e96fde3d73bed1496d2bc75d9dd62a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
 [[package]]
 name = "derive_more"
 version = "0.99.20"
@@ -4362,7 +4382,7 @@ checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
 [[package]]
 name = "voice-to-notes"
-version = "0.1.0"
+version = "0.2.2"
 dependencies = [
  "chrono",
  "rusqlite",
@@ -4374,6 +4394,7 @@ dependencies = [
  "tauri-plugin-opener",
  "thiserror 1.0.69",
  "uuid",
+ "zip",
 ]
 
 [[package]]
@@ -5412,12 +5433,41 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "zip"
+version = "2.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fabe6324e908f85a1c52063ce7aa26b68dcb7eb6dbc83a2d148403c9bc3eba50"
+dependencies = [
+ "arbitrary",
+ "crc32fast",
+ "crossbeam-utils",
+ "displaydoc",
+ "flate2",
+ "indexmap 2.13.0",
+ "memchr",
+ "thiserror 2.0.18",
+ "zopfli",
+]
+
 [[package]]
 name = "zmij"
 version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
 
+[[package]]
+name = "zopfli"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f05cd8797d63865425ff89b5c4a48804f35ba0ce8d125800027ad6017d2b5249"
+dependencies = [
+ "bumpalo",
+ "crc32fast",
+ "log",
+ "simd-adler32",
+]
+
 [[package]]
 name = "zvariant"
 version = "5.10.0"

src-tauri/Cargo.toml

@@ -24,3 +24,5 @@ zip = { version = "2", default-features = false, features = ["deflate"] }
 thiserror = "1"
 chrono = { version = "0.4", features = ["serde"] }
 tauri-plugin-dialog = "2.6.0"
+reqwest = { version = "0.12", features = ["stream"] }
+futures-util = "0.3"

src-tauri/src/commands/mod.rs

@@ -2,5 +2,6 @@ pub mod ai;
 pub mod export;
 pub mod project;
 pub mod settings;
+pub mod sidecar;
 pub mod system;
 pub mod transcribe;

src-tauri/src/commands/sidecar.rs

@@ -0,0 +1,211 @@
+use futures_util::StreamExt;
+use serde::Serialize;
+use std::io::Write;
+use tauri::{AppHandle, Emitter};
+
+use crate::sidecar::{SidecarManager, DATA_DIR};
+
+const REPO_API: &str = "https://repo.anhonesthost.net/api/v1/repos/MacroPad/voice-to-notes";
+
+#[derive(Serialize, Clone)]
+struct DownloadProgress {
+    downloaded: u64,
+    total: u64,
+    percent: u8,
+}
+
+#[derive(Serialize)]
+pub struct UpdateInfo {
+    pub current_version: String,
+    pub latest_version: String,
+}
+
+/// Check if the sidecar binary exists for the current version.
+#[tauri::command]
+pub fn check_sidecar() -> bool {
+    let data_dir = match DATA_DIR.get() {
+        Some(d) => d,
+        None => return false,
+    };
+    let binary_name = if cfg!(target_os = "windows") {
+        "voice-to-notes-sidecar.exe"
+    } else {
+        "voice-to-notes-sidecar"
+    };
+    let version = env!("CARGO_PKG_VERSION");
+    let extract_dir = data_dir.join(format!("sidecar-{}", version));
+    extract_dir.join(binary_name).exists()
+}
+
+/// Determine the current platform name for asset downloads.
+fn platform_os() -> &'static str {
+    if cfg!(target_os = "windows") {
+        "windows"
+    } else if cfg!(target_os = "macos") {
+        "macos"
+    } else {
+        "linux"
+    }
+}
+
+/// Determine the current architecture name for asset downloads.
+fn platform_arch() -> &'static str {
+    if cfg!(target_arch = "aarch64") {
+        "aarch64"
+    } else {
+        "x86_64"
+    }
+}
+
+/// Download the sidecar binary for the given variant (cpu or cuda).
+#[tauri::command]
+pub async fn download_sidecar(app: AppHandle, variant: String) -> Result<(), String> {
+    let data_dir = DATA_DIR.get().ok_or("App data directory not initialized")?;
+    let version = env!("CARGO_PKG_VERSION");
+
+    let os = platform_os();
+    let arch = platform_arch();
+    let asset_name = format!("sidecar-{}-{}-{}.zip", os, arch, variant);
+
+    // Fetch release info from Gitea API to get the download URL
+    let release_url = format!("{}/releases/tags/v{}", REPO_API, version);
+    let client = reqwest::Client::new();
+    let release_resp = client
+        .get(&release_url)
+        .header("Accept", "application/json")
+        .send()
+        .await
+        .map_err(|e| format!("Failed to fetch release info: {}", e))?;
+
+    if !release_resp.status().is_success() {
+        return Err(format!(
+            "Failed to fetch release info: HTTP {}",
+            release_resp.status()
+        ));
+    }
+
+    let release_json: serde_json::Value = release_resp
+        .json()
+        .await
+        .map_err(|e| format!("Failed to parse release JSON: {}", e))?;
+
+    // Find the matching asset
+    let assets = release_json["assets"]
+        .as_array()
+        .ok_or("No assets found in release")?;
+
+    let download_url = assets
+        .iter()
+        .find(|a| a["name"].as_str() == Some(&asset_name))
+        .and_then(|a| a["browser_download_url"].as_str())
+        .ok_or_else(|| format!("Asset '{}' not found in release v{}", asset_name, version))?
+        .to_string();
+
+    // Stream download with progress events
+    let response = reqwest::get(&download_url)
+        .await
+        .map_err(|e| format!("Failed to start download: {}", e))?;
+
+    if !response.status().is_success() {
+        return Err(format!("Download failed: HTTP {}", response.status()));
+    }
+
+    let total = response.content_length().unwrap_or(0);
+    let mut downloaded: u64 = 0;
+    let mut stream = response.bytes_stream();
+
+    let zip_path = data_dir.join("sidecar.zip");
+    let mut file = std::fs::File::create(&zip_path)
+        .map_err(|e| format!("Failed to create zip file: {}", e))?;
+
+    while let Some(chunk) = stream.next().await {
+        let chunk = chunk.map_err(|e| format!("Download stream error: {}", e))?;
+        file.write_all(&chunk)
+            .map_err(|e| format!("Failed to write chunk: {}", e))?;
+        downloaded += chunk.len() as u64;
+        let percent = if total > 0 {
+            (downloaded * 100 / total) as u8
+        } else {
+            0
+        };
+        let _ = app.emit(
+            "sidecar-download-progress",
+            DownloadProgress {
+                downloaded,
+                total,
+                percent,
+            },
+        );
+    }
+
+    // Extract the downloaded zip
+    let extract_dir = data_dir.join(format!("sidecar-{}", version));
+    SidecarManager::extract_zip(&zip_path, &extract_dir)?;
+
+    // Make the binary executable on Unix
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let binary_path = extract_dir.join("voice-to-notes-sidecar");
+        if let Ok(meta) = std::fs::metadata(&binary_path) {
+            let mut perms = meta.permissions();
+            perms.set_mode(0o755);
+            let _ = std::fs::set_permissions(&binary_path, perms);
+        }
+    }
+
+    // Clean up the zip file and old sidecar versions
+    let _ = std::fs::remove_file(&zip_path);
+    SidecarManager::cleanup_old_sidecars(data_dir, version);
+
+    Ok(())
+}
+
+/// Check if a sidecar update is available.
+#[tauri::command]
+pub async fn check_sidecar_update() -> Result<Option<UpdateInfo>, String> {
+    // If sidecar doesn't exist yet, return None (first launch handled separately)
+    if !check_sidecar() {
+        return Ok(None);
+    }
+
+    let current_version = env!("CARGO_PKG_VERSION").to_string();
+
+    // Fetch latest release from Gitea API
+    let latest_url = format!("{}/releases/latest", REPO_API);
+    let client = reqwest::Client::new();
+    let resp = client
+        .get(&latest_url)
+        .header("Accept", "application/json")
+        .send()
+        .await
+        .map_err(|e| format!("Failed to fetch latest release: {}", e))?;
+
+    if !resp.status().is_success() {
+        return Err(format!(
+            "Failed to fetch latest release: HTTP {}",
+            resp.status()
+        ));
+    }
+
+    let release_json: serde_json::Value = resp
+        .json()
+        .await
+        .map_err(|e| format!("Failed to parse release JSON: {}", e))?;
+
+    let latest_tag = release_json["tag_name"]
+        .as_str()
+        .ok_or("No tag_name in release")?;
+
+    // Strip leading 'v' if present
+    let latest_version = latest_tag.strip_prefix('v').unwrap_or(latest_tag);
+
+    if latest_version != current_version {
+        Ok(Some(UpdateInfo {
+            current_version,
+            latest_version: latest_version.to_string(),
+        }))
+    } else {
+        Ok(None)
+    }
+}

src-tauri/src/lib.rs

@@ -14,6 +14,7 @@ use commands::project::{
     load_project_transcript, save_project_file, save_project_transcript, update_segment,
 };
 use commands::settings::{load_settings, save_settings};
+use commands::sidecar::{check_sidecar, check_sidecar_update, download_sidecar};
 use commands::system::{get_data_dir, llama_list_models, llama_start, llama_status, llama_stop};
 use commands::transcribe::{download_diarize_model, run_pipeline, transcribe_file};
 use state::AppState;
@@ -65,6 +66,9 @@ pub fn run() {
             get_data_dir,
             load_settings,
             save_settings,
+            check_sidecar,
+            download_sidecar,
+            check_sidecar_update,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");

src-tauri/src/sidecar/mod.rs

@@ -14,7 +14,7 @@ use crate::sidecar::messages::IPCMessage;
 /// Resource directory set by the Tauri app during setup.
 static RESOURCE_DIR: OnceLock<PathBuf> = OnceLock::new();
 /// App data directory for extracting the sidecar archive.
-static DATA_DIR: OnceLock<PathBuf> = OnceLock::new();
+pub(crate) static DATA_DIR: OnceLock<PathBuf> = OnceLock::new();
 
 /// Initialize directories for sidecar resolution.
 /// Must be called from the Tauri setup before any sidecar operations.
@@ -136,7 +136,7 @@ impl SidecarManager {
     }
 
     /// Extract a zip archive to the given directory.
-    fn extract_zip(zip_path: &Path, dest: &Path) -> Result<(), String> {
+    pub(crate) fn extract_zip(zip_path: &Path, dest: &Path) -> Result<(), String> {
         eprintln!(
             "[sidecar-rs] Extracting sidecar from {} to {}",
             zip_path.display(),
@@ -185,7 +185,7 @@ impl SidecarManager {
 
     /// Remove old sidecar-* directories that don't match the current version.
     /// Called after the current version's sidecar is confirmed ready.
-    fn cleanup_old_sidecars(data_dir: &Path, current_version: &str) {
+    pub(crate) fn cleanup_old_sidecars(data_dir: &Path, current_version: &str) {
         let current_dir_name = format!("sidecar-{}", current_version);
 
         let entries = match std::fs::read_dir(data_dir) {

src-tauri/tauri.conf.json

@@ -31,7 +31,7 @@
   },
   "bundle": {
     "active": true,
-    "targets": ["deb", "rpm", "msi", "dmg"],
+    "targets": ["deb", "rpm", "nsis", "dmg"],
     "icon": [
       "icons/32x32.png",
       "icons/128x128.png",
@@ -42,7 +42,7 @@
     "category": "Utility",
     "shortDescription": "Transcribe audio/video with speaker identification",
     "longDescription": "Voice to Notes is a desktop application that transcribes audio and video recordings with speaker identification, synchronized playback, and AI-powered analysis. Export to SRT, WebVTT, ASS captions, or plain text.",
-    "resources": ["sidecar.zip"],
+    "resources": [],
     "copyright": "Voice to Notes Contributors",
     "license": "MIT",
     "linux": {

src/lib/components/SidecarSetup.svelte

@@ -0,0 +1,320 @@
+<script lang="ts">
+  import { invoke } from '@tauri-apps/api/core';
+  import { listen } from '@tauri-apps/api/event';
+  import type { UnlistenFn } from '@tauri-apps/api/event';
+  import { onMount } from 'svelte';
+
+  interface Props {
+    onComplete: () => void;
+  }
+
+  let { onComplete }: Props = $props();
+
+  let variant = $state<'cpu' | 'cuda'>('cpu');
+  let downloading = $state(false);
+  let downloadProgress = $state({ downloaded: 0, total: 0, percent: 0 });
+  let error = $state('');
+  let success = $state(false);
+
+  let unlisten: UnlistenFn | null = null;
+
+  onMount(() => {
+    return () => {
+      unlisten?.();
+    };
+  });
+
+  function formatBytes(bytes: number): string {
+    if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(0)} KB`;
+    if (bytes < 1024 * 1024 * 1024) return `${(bytes / (1024 * 1024)).toFixed(0)} MB`;
+    return `${(bytes / (1024 * 1024 * 1024)).toFixed(1)} GB`;
+  }
+
+  async function startDownload() {
+    downloading = true;
+    error = '';
+    success = false;
+
+    unlisten = await listen<{ downloaded: number; total: number; percent: number }>(
+      'sidecar-download-progress',
+      (event) => {
+        downloadProgress = event.payload;
+      }
+    );
+
+    try {
+      await invoke('download_sidecar', { variant });
+      success = true;
+      // Brief pause so the user sees "Complete" before the screen goes away
+      setTimeout(() => {
+        onComplete();
+      }, 800);
+    } catch (err) {
+      error = String(err);
+    } finally {
+      downloading = false;
+      unlisten?.();
+      unlisten = null;
+    }
+  }
+</script>
+
+<div class="setup-overlay">
+  <div class="setup-card">
+    <h1 class="app-title">Voice to Notes</h1>
+    <h2 class="setup-heading">First-Time Setup</h2>
+    <p class="setup-description">
+      Voice to Notes needs to download its AI engine to transcribe audio.
+    </p>
+
+    {#if !downloading && !success}
+      <div class="variant-options">
+        <label class="variant-option" class:selected={variant === 'cpu'}>
+          <input type="radio" name="variant" value="cpu" bind:group={variant} />
+          <div class="variant-info">
+            <span class="variant-label">Standard (CPU)</span>
+            <span class="variant-desc">Works on all computers (~500 MB download)</span>
+          </div>
+        </label>
+        <label class="variant-option" class:selected={variant === 'cuda'}>
+          <input type="radio" name="variant" value="cuda" bind:group={variant} />
+          <div class="variant-info">
+            <span class="variant-label">GPU Accelerated (CUDA)</span>
+            <span class="variant-desc">Faster transcription with NVIDIA GPU (~2 GB download)</span>
+          </div>
+        </label>
+      </div>
+
+      {#if error}
+        <div class="error-box">
+          <p class="error-text">{error}</p>
+          <button class="btn-retry" onclick={startDownload}>Retry</button>
+        </div>
+      {:else}
+        <button class="btn-download" onclick={startDownload}>
+          Download &amp; Install
+        </button>
+      {/if}
+    {:else if downloading}
+      <div class="progress-section">
+        <div class="progress-bar-track">
+          <div class="progress-bar-fill" style="width: {downloadProgress.percent}%"></div>
+        </div>
+        <p class="progress-text">
+          {downloadProgress.percent}% — {formatBytes(downloadProgress.downloaded)} / {formatBytes(downloadProgress.total)}
+        </p>
+        <p class="progress-hint">Downloading {variant === 'cuda' ? 'GPU' : 'CPU'} engine...</p>
+      </div>
+    {:else if success}
+      <div class="success-section">
+        <div class="success-icon">&#10003;</div>
+        <p class="success-text">Setup complete!</p>
+      </div>
+    {/if}
+  </div>
+</div>
+
+<style>
+  .setup-overlay {
+    position: fixed;
+    inset: 0;
+    background: #0a0a23;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 10000;
+  }
+
+  .setup-card {
+    background: #16213e;
+    border: 1px solid #2a3a5e;
+    border-radius: 12px;
+    padding: 2.5rem 3rem;
+    max-width: 480px;
+    width: 90vw;
+    color: #e0e0e0;
+    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
+    text-align: center;
+  }
+
+  .app-title {
+    font-size: 1.8rem;
+    margin: 0 0 0.25rem;
+    color: #e94560;
+    font-weight: 700;
+  }
+
+  .setup-heading {
+    font-size: 1.1rem;
+    margin: 0 0 0.75rem;
+    color: #e0e0e0;
+    font-weight: 500;
+  }
+
+  .setup-description {
+    font-size: 0.9rem;
+    color: #b0b0b0;
+    margin: 0 0 1.5rem;
+    line-height: 1.5;
+  }
+
+  .variant-options {
+    display: flex;
+    flex-direction: column;
+    gap: 0.75rem;
+    margin-bottom: 1.5rem;
+    text-align: left;
+  }
+
+  .variant-option {
+    display: flex;
+    align-items: flex-start;
+    gap: 0.75rem;
+    padding: 0.85rem 1rem;
+    border: 1px solid #2a3a5e;
+    border-radius: 8px;
+    cursor: pointer;
+    transition: border-color 0.15s, background 0.15s;
+  }
+
+  .variant-option:hover {
+    border-color: #4a5568;
+    background: rgba(255, 255, 255, 0.02);
+  }
+
+  .variant-option.selected {
+    border-color: #e94560;
+    background: rgba(233, 69, 96, 0.08);
+  }
+
+  .variant-option input[type='radio'] {
+    margin-top: 0.2rem;
+    accent-color: #e94560;
+    flex-shrink: 0;
+  }
+
+  .variant-info {
+    display: flex;
+    flex-direction: column;
+    gap: 0.2rem;
+  }
+
+  .variant-label {
+    font-size: 0.9rem;
+    font-weight: 500;
+    color: #e0e0e0;
+  }
+
+  .variant-desc {
+    font-size: 0.78rem;
+    color: #888;
+  }
+
+  .btn-download {
+    background: #e94560;
+    border: none;
+    color: white;
+    padding: 0.7rem 1.5rem;
+    border-radius: 6px;
+    cursor: pointer;
+    font-size: 0.9rem;
+    font-weight: 500;
+    width: 100%;
+    transition: background 0.15s;
+  }
+
+  .btn-download:hover {
+    background: #d63851;
+  }
+
+  .progress-section {
+    margin-top: 0.5rem;
+  }
+
+  .progress-bar-track {
+    width: 100%;
+    height: 8px;
+    background: #1a1a2e;
+    border-radius: 4px;
+    overflow: hidden;
+    border: 1px solid #2a3a5e;
+  }
+
+  .progress-bar-fill {
+    height: 100%;
+    background: #e94560;
+    border-radius: 4px;
+    transition: width 0.3s ease;
+  }
+
+  .progress-text {
+    margin: 0.75rem 0 0;
+    font-size: 0.85rem;
+    color: #e0e0e0;
+    font-variant-numeric: tabular-nums;
+  }
+
+  .progress-hint {
+    margin: 0.35rem 0 0;
+    font-size: 0.78rem;
+    color: #888;
+  }
+
+  .error-box {
+    background: rgba(233, 69, 96, 0.1);
+    border: 1px solid rgba(233, 69, 96, 0.3);
+    border-radius: 8px;
+    padding: 1rem;
+  }
+
+  .error-text {
+    color: #e94560;
+    font-size: 0.85rem;
+    margin: 0 0 0.75rem;
+    word-break: break-word;
+    line-height: 1.4;
+  }
+
+  .btn-retry {
+    background: #e94560;
+    border: none;
+    color: white;
+    padding: 0.5rem 1.25rem;
+    border-radius: 6px;
+    cursor: pointer;
+    font-size: 0.85rem;
+    font-weight: 500;
+  }
+
+  .btn-retry:hover {
+    background: #d63851;
+  }
+
+  .success-section {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 0.5rem;
+    padding: 1rem 0;
+  }
+
+  .success-icon {
+    width: 48px;
+    height: 48px;
+    border-radius: 50%;
+    background: rgba(78, 205, 196, 0.15);
+    color: #4ecdc4;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    font-size: 1.5rem;
+    font-weight: 700;
+  }
+
+  .success-text {
+    color: #4ecdc4;
+    font-size: 1rem;
+    margin: 0;
+    font-weight: 500;
+  }
+</style>

src/routes/+page.svelte

@@ -8,6 +8,7 @@
   import AIChatPanel from '$lib/components/AIChatPanel.svelte';
   import ProgressOverlay from '$lib/components/ProgressOverlay.svelte';
   import SettingsModal from '$lib/components/SettingsModal.svelte';
+  import SidecarSetup from '$lib/components/SidecarSetup.svelte';
   import { segments, speakers } from '$lib/stores/transcript';
   import { settings, loadSettings } from '$lib/stores/settings';
   import type { Segment, Speaker } from '$lib/types/transcript';
@@ -18,13 +19,56 @@
   let audioUrl = $state('');
   let showSettings = $state(false);
 
+  // Sidecar state
+  let sidecarReady = $state(false);
+  let sidecarChecked = $state(false);
+
+  // Sidecar update state
+  let sidecarUpdate = $state<{ current_version: string; latest_version: string } | null>(null);
+  let showUpdateDownload = $state(false);
+  let updateDismissed = $state(false);
+
   // Project management state
   let currentProjectPath = $state<string | null>(null);
   let currentProjectName = $state('');
   let audioFilePath = $state('');
 
+  async function checkSidecar() {
+    try {
+      const ready = await invoke<boolean>('check_sidecar');
+      sidecarReady = ready;
+    } catch {
+      sidecarReady = false;
+    }
+    sidecarChecked = true;
+  }
+
+  async function checkSidecarUpdate() {
+    try {
+      const update = await invoke<{ current_version: string; latest_version: string } | null>('check_sidecar_update');
+      sidecarUpdate = update;
+    } catch {
+      // Silently ignore update check failures
+    }
+  }
+
+  function handleSidecarSetupComplete() {
+    sidecarReady = true;
+    checkSidecarUpdate();
+  }
+
+  function handleUpdateComplete() {
+    showUpdateDownload = false;
+    sidecarUpdate = null;
+  }
+
   onMount(() => {
     loadSettings();
+    checkSidecar().then(() => {
+      if (sidecarReady) {
+        checkSidecarUpdate();
+      }
+    });
 
     // Global keyboard shortcuts
     function handleKeyDown(e: KeyboardEvent) {
@@ -443,14 +487,31 @@
   }
 </script>
 
-{#if !appReady}
+{#if !appReady || !sidecarChecked}
   <div class="splash-screen">
     <h1 class="splash-title">Voice to Notes</h1>
     <p class="splash-subtitle">Loading...</p>
     <div class="splash-spinner"></div>
   </div>
+{:else if sidecarChecked && !sidecarReady && !showUpdateDownload}
+  <SidecarSetup onComplete={handleSidecarSetupComplete} />
+{:else if showUpdateDownload}
+  <SidecarSetup onComplete={handleUpdateComplete} />
 {:else}
   <div class="app-shell">
+  {#if sidecarUpdate && !updateDismissed}
+    <div class="update-banner">
+      <span class="update-text">
+        Sidecar update available (v{sidecarUpdate.current_version} &rarr; v{sidecarUpdate.latest_version})
+      </span>
+      <button class="update-btn" onclick={() => showUpdateDownload = true}>
+        Update
+      </button>
+      <button class="update-dismiss" onclick={() => updateDismissed = true} title="Dismiss">
+        &times;
+      </button>
+    </div>
+  {/if}
   <div class="app-header">
     <div class="header-actions">
       <button class="settings-btn" onclick={openProject} disabled={isTranscribing}>
@@ -674,4 +735,45 @@
   @keyframes spin {
     to { transform: rotate(360deg); }
   }
+
+  /* Sidecar update banner */
+  .update-banner {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+    padding: 0.5rem 1rem;
+    background: rgba(78, 205, 196, 0.1);
+    border-bottom: 1px solid rgba(78, 205, 196, 0.25);
+    color: #e0e0e0;
+    font-size: 0.85rem;
+  }
+  .update-text {
+    flex: 1;
+    color: #b0b0b0;
+  }
+  .update-btn {
+    background: #4ecdc4;
+    border: none;
+    color: #0a0a23;
+    padding: 0.3rem 0.85rem;
+    border-radius: 4px;
+    cursor: pointer;
+    font-size: 0.8rem;
+    font-weight: 600;
+  }
+  .update-btn:hover {
+    background: #3dbdb5;
+  }
+  .update-dismiss {
+    background: none;
+    border: none;
+    color: #888;
+    font-size: 1.1rem;
+    cursor: pointer;
+    padding: 0.1rem 0.3rem;
+    line-height: 1;
+  }
+  .update-dismiss:hover {
+    color: #e0e0e0;
+  }
 </style>