Terminal file viewer/editor + per-window app-command lockdown (#60)

Clicking a file path in Claude's terminal output now opens the file in its own window with a CodeMirror 6 editor. The editor highlights the target line, live-reloads while the file changes, and saves explicitly with hash-based conflict detection. The viewer commands are gated by window label.

Every app command is now ACL-gated per window through a Tauri AppManifest. build.rs checks the handler list against the capability files and fails the build on any mismatch.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

app/src/components/projects/home/filePreview.test.ts

@@ -3,6 +3,7 @@ import {
   IMAGE_PREVIEW_LIMIT,
   TEXT_PREVIEW_LIMIT,
   decodeBase64,
+  encodeBase64,
   extensionOf,
   imageMimeFor,
   looksBinary,
@@ -76,3 +77,22 @@ describe("decodeBase64 / looksBinary", () => {
     expect(looksBinary(bytes)).toBe(false);
   });
 });
+
+describe("encodeBase64", () => {
+  it("matches btoa on a small input", () => {
+    expect(encodeBase64(new Uint8Array([0xff, 0xd8, 0x00, 0x41]))).toBe(btoa("\xff\xd8\x00\x41"));
+  });
+
+  it("round-trips 1 MiB without overflowing the call stack", () => {
+    // Spreading a 1 MiB array into String.fromCharCode throws RangeError in V8.
+    const bytes = new Uint8Array(TEXT_PREVIEW_LIMIT);
+    for (let i = 0; i < bytes.length; i++) bytes[i] = (i * 31 + 7) & 0xff;
+    const back = decodeBase64(encodeBase64(bytes));
+    expect(back.length).toBe(bytes.length);
+    expect(back.every((b, i) => b === bytes[i])).toBe(true);
+  });
+
+  it("encodes an empty input as the empty string", () => {
+    expect(encodeBase64(new Uint8Array(0))).toBe("");
+  });
+});

app/src/components/projects/home/filePreview.ts

@@ -96,6 +96,19 @@ export function decodeBase64(base64: string): Uint8Array<ArrayBuffer> {
   return bytes;
 }
 
+/**
+ * Bytes → base64. Built 32 KiB at a time: spreading a whole buffer into
+ * `String.fromCharCode` overflows the argument limit well below 1 MiB.
+ */
+export function encodeBase64(bytes: Uint8Array): string {
+  const CHUNK = 0x8000;
+  let binary = "";
+  for (let i = 0; i < bytes.length; i += CHUNK) {
+    binary += String.fromCharCode(...bytes.subarray(i, i + CHUNK));
+  }
+  return btoa(binary);
+}
+
 /**
  * The classic heuristic: a NUL byte early on means this is not text. Cheap,
  * and it is what `git` and `grep` use to decide the same question.

app/src/components/terminal/TerminalView.test.tsx

@@ -5,10 +5,12 @@ import TerminalView, {
   createOsc8LinkHandler,
   supersedes,
 } from "./TerminalView";
+import { Terminal } from "@xterm/xterm";
 import { useAppState } from "../../store/appState";
 import {
   uploadHostFileToTerminal,
   openUrlExternal,
+  openFileViewer,
 } from "../../lib/tauri-commands";
 import {
   chooseSignInTarget,
@@ -123,6 +125,7 @@ vi.mock("../../lib/tauri-commands", () => ({
   getAuthBridgeStatus: vi.fn(async () => containerEnv.bridge),
   checkBrowserViewSupport: vi.fn(async () => containerEnv.detection),
   openUrlExternal: vi.fn(async () => {}),
+  openFileViewer: vi.fn(async () => {}),
 }));
 
 vi.mock("@tauri-apps/api/event", () => ({
@@ -1606,6 +1609,78 @@ describe("createOsc8LinkHandler — clicking a link Claude Code printed", () =>
     expect(hoverCard()).toBeNull();
   });
 
+  it("routes a file: target to the viewer and never to the opener", () => {
+    const onOpenFile = vi.fn();
+    const h = createOsc8LinkHandler(() => host, () => state, onOpenFile);
+    h.activate(click(), "file:///workspace/p/src/a.ts", range);
+    expect(onOpenFile).toHaveBeenCalledWith("/workspace/p/src/a.ts");
+    expect(openUrlExternal).not.toHaveBeenCalled();
+  });
+
+  it("with non-http targets now delivered, still refuses javascript: and garbage", () => {
+    const onOpenFile = vi.fn();
+    const h = createOsc8LinkHandler(() => host, () => state, onOpenFile);
+    h.activate(click(), "javascript:alert(1)", range);
+    h.activate(click(), "not a url", range);
+    h.hover?.(new MouseEvent("mousemove"), "javascript:alert(1)", range);
+    expect(onOpenFile).not.toHaveBeenCalled();
+    expect(openUrlExternal).not.toHaveBeenCalled();
+    // The refusal card (ruling (a)): present, no origin, never the target,
+    // never an offer to open it.
+    const card = hoverCard();
+    expect(card).not.toBeNull();
+    expect(card!.querySelector('[data-testid="osc8-hover-origin"]')).toBeNull();
+    expect(card!.textContent).toContain("will not be opened");
+    expect(card!.textContent).not.toContain("javascript:");
+    expect(card!.textContent).not.toContain("Open in viewer");
+  });
+
+  it("refuses a file: target whose escapes do not decode", () => {
+    const onOpenFile = vi.fn();
+    const h = createOsc8LinkHandler(() => host, () => state, onOpenFile);
+    h.activate(click(), "file:///workspace/%E0%A4%A", range);
+    h.hover?.(new MouseEvent("mousemove"), "file:///workspace/%E0%A4%A", range);
+    expect(onOpenFile).not.toHaveBeenCalled();
+    const card = hoverCard();
+    expect(card).not.toBeNull();
+    expect(card!.querySelector('[data-testid="osc8-hover-origin"]')).toBeNull();
+    expect(card!.textContent).toContain("will not be opened");
+    expect(card!.textContent).not.toContain("Open in viewer");
+  });
+
+  it("the file: hover card names the viewer and the path", () => {
+    const h = createOsc8LinkHandler(() => host, () => state, vi.fn());
+    h.hover?.(new MouseEvent("mousemove"), "file:///workspace/p/README.md", range);
+    expect(hoverCard()?.textContent).toContain("Open in viewer");
+    expect(hoverCard()?.textContent).toContain("/workspace/p/README.md");
+  });
+
+  it("shows a relative path's card with the path as printed (preflight P6)", () => {
+    const h = createOsc8LinkHandler(() => host, () => state, vi.fn());
+    h.showFileCard("src/foo.ts");
+    expect(hoverCard()?.textContent).toContain("Open in viewer");
+    expect(hoverCard()?.textContent).toContain("src/foo.ts");
+    h.dismiss();
+    expect(hoverCard()).toBeNull();
+  });
+
+  it("holds a file-path click to the modifier its card promised", () => {
+    const h = createOsc8LinkHandler(() => host, () => state, vi.fn());
+    state.mouseTracking = true;
+    h.showFileCard("src/foo.ts");
+    expect(hoverCard()?.textContent).toContain("Shift+click");
+    state.mouseTracking = false;
+    expect(h.opensFileLink(click())).toBe(false);
+    expect(h.opensFileLink(click({ shiftKey: true }))).toBe(true);
+    // A card drawn with nothing tracking promises nothing.
+    h.showFileCard("src/foo.ts");
+    expect(h.opensFileLink(click())).toBe(true);
+  });
+
+  it("declares allowNonHttpProtocols so file: targets reach it", () => {
+    expect(createOsc8LinkHandler(() => host, () => state).allowNonHttpProtocols).toBe(true);
+  });
+
   it("pushes the shared toast when the host opener fails", async () => {
     vi.mocked(openUrlExternal).mockRejectedValueOnce(new Error("no opener"));
 
@@ -1656,6 +1731,124 @@ describe("the link handler is wired into the terminal, and reads its live mode",
     expect(typeof handler.hover).toBe("function");
   });
 
+  it("opens a file: target in the viewer against the session's project", async () => {
+    vi.mocked(openFileViewer).mockClear();
+    mountSession("bash");
+
+    await act(async () => {
+      wiredHandler().activate(
+        new MouseEvent("click", { button: 0, detail: 1 }),
+        "file:///workspace/api/src/a%20b.ts",
+        range,
+      );
+      await Promise.resolve();
+    });
+
+    expect(openFileViewer).toHaveBeenCalledWith(
+      "p1", "/workspace/api/src/a b.ts", undefined, undefined, undefined,
+    );
+    expect(openUrlExternal).not.toHaveBeenCalled();
+  });
+
+  it("registers the file-path provider, which opens the viewer at the matched line", async () => {
+    vi.mocked(openFileViewer).mockClear();
+    const register = vi.spyOn(Terminal.prototype, "registerLinkProvider");
+    try {
+      mountSession("bash");
+      const provider = register.mock.calls.at(-1)?.[0];
+      if (!provider) throw new Error("no link provider was registered");
+
+      await write("Edited src/foo.ts:42 today");
+      const links = vi.fn();
+      provider.provideLinks(1, links);
+      const [link] = links.mock.calls[0][0];
+      expect(link.text).toBe("src/foo.ts:42");
+
+      await act(async () => {
+        link.activate(new MouseEvent("click", { button: 0, detail: 1 }), link.text);
+        await Promise.resolve();
+      });
+      expect(openFileViewer).toHaveBeenCalledWith("p1", "src/foo.ts", 42, undefined, undefined);
+    } finally {
+      register.mockRestore();
+    }
+  });
+
+  it("says so in a toast when the viewer refuses to open", async () => {
+    vi.mocked(openFileViewer).mockRejectedValueOnce(new Error("No such file: x.ts"));
+    mountSession("bash");
+
+    await act(async () => {
+      wiredHandler().activate(
+        new MouseEvent("click", { button: 0, detail: 1 }),
+        "file:///x.ts",
+        range,
+      );
+      await Promise.resolve();
+      await Promise.resolve();
+    });
+
+    const toasts = useAppState.getState().toasts;
+    expect(toasts.at(-1)?.detail).toContain("No such file: x.ts");
+    expect(toasts.at(-1)?.dedupeKey).toBe("file-viewer-open");
+  });
+
+  it("holds a plain-text file link to the modifier its hover card promised", async () => {
+    vi.mocked(openFileViewer).mockClear();
+    const platform = navigator.platform;
+    Object.defineProperty(navigator, "platform", { value: "Linux x86_64", configurable: true });
+    const register = vi.spyOn(Terminal.prototype, "registerLinkProvider");
+    try {
+      mountSession("claude");
+      const provider = register.mock.calls.at(-1)?.[0];
+      if (!provider) throw new Error("no link provider was registered");
+      await write("Edited src/foo.ts:42 today");
+      const links = vi.fn();
+      provider.provideLinks(1, links);
+      const [link] = links.mock.calls[0][0];
+
+      await write("\x1b[?1002h");
+      link.hover?.(new MouseEvent("mousemove"), link.text);
+      expect(document.body.textContent).toContain("Shift+click to open");
+      await write("\x1b[?1002l");
+
+      await act(async () => {
+        link.activate(new MouseEvent("click", { button: 0, detail: 1 }), link.text);
+        await Promise.resolve();
+      });
+      expect(openFileViewer).not.toHaveBeenCalled();
+
+      await act(async () => {
+        link.activate(
+          new MouseEvent("click", { button: 0, detail: 1, shiftKey: true }),
+          link.text,
+        );
+        await Promise.resolve();
+      });
+      expect(openFileViewer).toHaveBeenCalledWith("p1", "src/foo.ts", 42, undefined, undefined);
+    } finally {
+      register.mockRestore();
+      Object.defineProperty(navigator, "platform", { value: platform, configurable: true });
+    }
+  });
+
+  it("says the project is not ready rather than doing nothing", async () => {
+    vi.mocked(openFileViewer).mockClear();
+    useAppState.setState({ sessions: [] });
+    render(<TerminalView sessionId="s-unknown" active />);
+
+    wiredHandler().activate(
+      new MouseEvent("click", { button: 0, detail: 1 }),
+      "file:///workspace/api/README.md",
+      range,
+    );
+
+    expect(openFileViewer).not.toHaveBeenCalled();
+    const toasts = useAppState.getState().toasts;
+    expect(toasts.at(-1)?.detail).toContain("not ready yet");
+    expect(toasts.at(-1)?.dedupeKey).toBe("file-viewer-open");
+  });
+
   // The gate has to ask the terminal, not a boolean captured at construction:
   // the mode changes whenever the container prints a DECSET, which is several
   // times a second in Claude Code.
@@ -1695,10 +1888,9 @@ describe("the link handler is wired into the terminal, and reads its live mode",
  *
  * `WebLinksAddon` matches rendered text and activates through the same
  * `Linkifier._handleMouseUp`, with the same absence of any check. It also
- * picks up links the OSC 8 handler never sees: `OscLinkProvider` drops a
- * non-http(s) hyperlink target before `linkHandler` is reached, which leaves
- * the addon free to match the *label* — so an OSC 8 with a `javascript:`
- * target and an `https://evil.tld/x` label arrives here and nowhere else.
+ * covers the plain-text URLs that carry no OSC 8 parameter at all. (Since the
+ * file viewer, `allowNonHttpProtocols` is on, so every OSC 8 target reaches
+ * the OSC 8 handler, which refuses anything but `file:` and `http(s):`.)
  * Both routes end at `openUrlExternal`, so both ask the same question first.
  */
 describe("the plain-text URL path is gated the same way", () => {

app/src/components/terminal/TerminalView.tsx

@@ -9,6 +9,7 @@ import { useAppState } from "../../store/appState";
 import { CLAUDE_SOFT_NEWLINE } from "../../lib/claudeInput";
 import {
   awsSsoRefresh,
+  openFileViewer,
   openPageInContainerBrowser,
   openUrlExternal,
   uploadHostFileToTerminal,
@@ -33,6 +34,8 @@ import UrlToast, {
 import { trimSelection } from "./trimSelection";
 import { resolveTerminalGpuRendering } from "../../lib/terminalRenderer";
 import TerminalContextMenu from "./TerminalContextMenu";
+import { createFilePathLinkProvider } from "./filePathLinkProvider";
+import type { FilePathMatch } from "../../lib/filePathLinks";
 
 interface Props {
   sessionId: string;
@@ -137,6 +140,40 @@ function reportOpenFailure(e: unknown) {
   });
 }
 
+/**
+ * Open a path in the file viewer for this terminal's project, or say why not.
+ * The session record (and so the project) can arrive after the first render;
+ * a click in that window gets a toast rather than silently doing nothing.
+ */
+function openInViewer(
+  projectId: string | undefined,
+  path: string,
+  line?: number,
+  col?: number,
+  endLine?: number,
+): void {
+  if (!projectId) {
+    useAppState.getState().pushToast({
+      kind: "error",
+      message: "Could not open the file",
+      detail: "This terminal's project is not ready yet",
+      dedupeKey: "file-viewer-open",
+    });
+    return;
+  }
+  openFileViewer(projectId, path, line, col, endLine).catch(reportViewerFailure);
+}
+
+/** Report a file-viewer open that the backend refused (not found, no container, cap). */
+function reportViewerFailure(e: unknown): void {
+  useAppState.getState().pushToast({
+    kind: "error",
+    message: "Could not open the file",
+    detail: e instanceof Error ? e.message : String(e),
+    dedupeKey: "file-viewer-open",
+  });
+}
+
 /**
  * `ILinkHandler`, plus the one thing xterm never asks for.
  *
@@ -146,7 +183,50 @@ function reportOpenFailure(e: unknown) {
  * pane and is still there when the user comes back. {@link dismiss} is how the
  * view says "this pane is gone" without pretending to be a mouse event.
  */
-export type Osc8LinkHandler = ILinkHandler & { dismiss(): void };
+export type Osc8LinkHandler = ILinkHandler & {
+  dismiss(): void;
+  /**
+   * Draw the "Open in viewer" card for a path matched in plain text by the
+   * file-path link provider. Takes the raw path (a relative path stays
+   * relative — `file://src/x` would parse `src` as a host). Records the
+   * card's modifier promise exactly as `hover` does, so
+   * {@link opensFileLink} can hold the click to it.
+   */
+  showFileCard(path: string): void;
+  /**
+   * The file-path provider's click gate: {@link opensOnClick} with whatever
+   * the card on screen promised. There is only ever one card, and `clear()`
+   * resets the promise with it, so sharing the flag with OSC 8 links is exact.
+   */
+  opensFileLink(event: MouseEvent): boolean;
+};
+
+/**
+ * What an OSC 8 target is, now that `allowNonHttpProtocols` delivers every
+ * scheme here. `null` is anything this pane refuses: unparseable, a scheme
+ * other than `file:`/`http(s):`, or a `file:` path whose escapes do not decode.
+ * The host of a `file:` URL is ignored — `ls --hyperlink` writes the machine's
+ * hostname there, and the viewer only ever reads the container.
+ */
+function classifyOsc8Target(
+  text: string,
+): { kind: "file"; path: string } | { kind: "web" } | null {
+  let parsed: URL;
+  try {
+    parsed = new URL(text);
+  } catch {
+    return null;
+  }
+  if (parsed.protocol === "file:") {
+    try {
+      return { kind: "file", path: decodeURIComponent(parsed.pathname) };
+    } catch {
+      return null;
+    }
+  }
+  if (parsed.protocol === "http:" || parsed.protocol === "https:") return { kind: "web" };
+  return null;
+}
 
 /**
  * Is a program holding the mouse?
@@ -397,10 +477,14 @@ function opensOnClick(
  * @param readState samples {@link ClickContext} — a getter for the same
  *        reason, and the *only* reason: every one of those answers changes
  *        under us, between the hover and the click that follows it.
+ * @param onOpenFile receives the decoded path of a `file:` target, which
+ *        opens in the file viewer rather than the host browser. Without it a
+ *        `file:` target is inert.
  */
 export function createOsc8LinkHandler(
   getHost: () => HTMLElement | null,
   readState: () => ClickContext,
+  onOpenFile?: (path: string) => void,
 ): Osc8LinkHandler {
   let card: HTMLDivElement | null = null;
   /**
@@ -428,6 +512,64 @@ export function createOsc8LinkHandler(
     return el;
   };
 
+  const makeCard = (): HTMLDivElement => {
+    const el = document.createElement("div");
+    el.className = OSC8_HOVER_CLASS;
+    el.dataset.testid = "osc8-hover";
+    Object.assign(el.style, {
+      position: "absolute",
+      left: "8px",
+      bottom: "8px",
+      maxWidth: "calc(100% - 16px)",
+      boxSizing: "border-box",
+      zIndex: "30",
+      // The card lands under the pointer for a link in the bottom rows, and
+      // it is not a sibling the Linkifier hit-tests around (see
+      // `OSC8_HOVER_CLASS`). Without this, `screenElement` gets `mouseleave`
+      // the moment the card appears — card removed, pointer back on the
+      // link, card back: a flicker loop — and worse, the `mouseup` that
+      // activates the link lands on the card, so the link cannot be opened
+      // at all. Nothing here is interactive, so nothing is lost.
+      pointerEvents: "none",
+      display: "flex",
+      alignItems: "baseline",
+      gap: "6px",
+      padding: "3px 8px",
+      fontSize: "12px",
+      fontFamily: "monospace",
+      background: "var(--bg-secondary)",
+      border: "1px solid var(--border-color)",
+      // The origin wraps, so the card grows downward rather than sideways;
+      // this is the backstop for anything that still cannot fit.
+      overflow: "hidden",
+      borderRadius: "6px",
+      boxShadow: "var(--shadow-overlay)",
+      color: "var(--text-primary)",
+    } as Partial<CSSStyleDeclaration>);
+    return el;
+  };
+
+  /** "Open in viewer", the path, and the same hint line as a web link. */
+  const fillFileCard = (el: HTMLDivElement, path: string, ctx: ClickContext) => {
+    el.appendChild(span("Open in viewer", { fontWeight: "700", flexShrink: "0" }));
+    const pathEl = span(path, {
+      color: "var(--text-secondary)",
+      overflow: "hidden",
+      textOverflow: "ellipsis",
+      whiteSpace: "nowrap",
+      minWidth: "0",
+    });
+    pathEl.dataset.testid = "osc8-hover-path";
+    el.appendChild(pathEl);
+    el.appendChild(
+      span(openHintLabel(ctx), {
+        color: "var(--text-secondary)",
+        flexShrink: "0",
+        marginLeft: "4px",
+      }),
+    );
+  };
+
   return {
     activate(event, text) {
       // Opening the host browser is the one thing in this pane the container
@@ -435,6 +577,16 @@ export function createOsc8LinkHandler(
       // may provoke by accident. See `opensOnClick` — including the residual
       // it does not close.
       if (!opensOnClick(event, readState(), modifierPromised)) return;
+      const target = classifyOsc8Target(text);
+      if (!target) {
+        console.warn("Refusing to open a link with an unsupported or malformed target");
+        return;
+      }
+      if (target.kind === "file") {
+        if (!onOpenFile) return;
+        onOpenFile(target.path);
+        return;
+      }
       // Same sink and same rule as the WebLinksAddon branch: this came off the
       // container's output, so it is validated before it reaches the OS
       // opener. One implementation — `sanitizeRelayUrl` — on purpose.
@@ -456,39 +608,16 @@ export function createOsc8LinkHandler(
       // moved on by the time they click.
       modifierPromised = ctx.mouseTracking;
 
-      card = document.createElement("div");
-      card.className = OSC8_HOVER_CLASS;
-      card.dataset.testid = "osc8-hover";
-      Object.assign(card.style, {
-        position: "absolute",
-        left: "8px",
-        bottom: "8px",
-        maxWidth: "calc(100% - 16px)",
-        boxSizing: "border-box",
-        zIndex: "30",
-        // The card lands under the pointer for a link in the bottom rows, and
-        // it is not a sibling the Linkifier hit-tests around (see
-        // `OSC8_HOVER_CLASS`). Without this, `screenElement` gets `mouseleave`
-        // the moment the card appears — card removed, pointer back on the
-        // link, card back: a flicker loop — and worse, the `mouseup` that
-        // activates the link lands on the card, so the link cannot be opened
-        // at all. Nothing here is interactive, so nothing is lost.
-        pointerEvents: "none",
-        display: "flex",
-        alignItems: "baseline",
-        gap: "6px",
-        padding: "3px 8px",
-        fontSize: "12px",
-        fontFamily: "monospace",
-        background: "var(--bg-secondary)",
-        border: "1px solid var(--border-color)",
-        // The origin wraps, so the card grows downward rather than sideways;
-        // this is the backstop for anything that still cannot fit.
-        overflow: "hidden",
-        borderRadius: "6px",
-        boxShadow: "var(--shadow-overlay)",
-        color: "var(--text-primary)",
-      } as Partial<CSSStyleDeclaration>);
+      card = makeCard();
+
+      const target = classifyOsc8Target(text);
+      // Without a viewer to hand it to, a `file:` target falls through to the
+      // refusal card below rather than offering something the click won't do.
+      if (target?.kind === "file" && onOpenFile) {
+        fillFileCard(card, target.path, ctx);
+        host.appendChild(card);
+        return;
+      }
 
       const safe = sanitizeRelayUrl(text);
       const origin = safe && urlOrigin(safe);
@@ -549,6 +678,25 @@ export function createOsc8LinkHandler(
     leave: clear,
 
     dismiss: clear,
+
+    showFileCard(path) {
+      clear();
+      const host = getHost();
+      if (!host) return;
+      const ctx = readState();
+      // Same promise as `hover`: the card names a modifier, so the click is
+      // held to it even if the container drops tracking before it lands.
+      modifierPromised = ctx.mouseTracking;
+      card = makeCard();
+      fillFileCard(card, path, ctx);
+      host.appendChild(card);
+    },
+
+    opensFileLink(event) {
+      return opensOnClick(event, readState(), modifierPromised);
+    },
+
+    allowNonHttpProtocols: true,
   };
 }
 
@@ -573,6 +721,13 @@ export default function TerminalView({ sessionId, active }: Props) {
   const projectId = useAppState(
     (s) => s.sessions.find((sess) => sess.id === sessionId)?.projectId
   );
+  // The file viewer opens against the session's project. Read through a ref
+  // because the link handlers are built in the mount effect, keyed on
+  // `sessionId` only, and the session record can arrive after the first render.
+  const projectIdRef = useRef<string | undefined>(projectId);
+  useEffect(() => {
+    projectIdRef.current = projectId;
+  }, [projectId]);
 
   // Which program is on the other end of the PTY. Read through a ref because
   // the key handler is registered once, in the mount effect keyed on
@@ -882,6 +1037,7 @@ export default function TerminalView({ sessionId, active }: Props) {
       linkHandler: (osc8LinkHandlerRef.current = createOsc8LinkHandler(
         () => term.element ?? null,
         () => readClickContext(term),
+        (path) => openInViewer(projectIdRef.current, path),
       )),
       fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', Menlo, Monaco, monospace",
       theme: {
@@ -924,12 +1080,10 @@ export default function TerminalView({ sessionId, active }: Props) {
       // got a browser open on a plain click while it held the mouse, and a
       // double-click that merely selected a URL opened it.
       //
-      // It is also the only gate on a real bypass of the OSC 8 one:
-      // `OscLinkProvider` drops a hyperlink whose target is not http(s)
-      // *before* `linkHandler` sees it (`allowNonHttpProtocols` is unset), so
-      // an OSC 8 carrying a `javascript:` target and an `https://evil.tld/x`
-      // label leaves the addon free to match the label. That click arrives
-      // here and nowhere else.
+      // `allowNonHttpProtocols` is now **on**, so `OscLinkProvider` hands every
+      // OSC 8 target to `createOsc8LinkHandler`, which parses it and refuses
+      // anything but `file:` (the file viewer) and `http(s):` itself. This
+      // branch remains the only handler for plain-text URLs.
       //
       // No `modifierPromised`: this path paints an underline rather than a
       // card, so it promises the user nothing to be held to.
@@ -952,6 +1106,24 @@ export default function TerminalView({ sessionId, active }: Props) {
     }, { urlRegex });
     term.loadAddon(webLinksAddon);
 
+    // File paths in plain text open in the file viewer. Registered after the
+    // addon so URLs are claimed first; the matcher also refuses anything
+    // inside a `scheme://` span. The hover card is the OSC 8 handler's, fed the
+    // raw path, and the click gate honours the modifier that card promised.
+    const filePathLinks = term.registerLinkProvider(
+      createFilePathLinkProvider(
+        term,
+        (m: FilePathMatch) =>
+          openInViewer(projectIdRef.current, m.path, m.line, m.col, m.endLine),
+        // Held to what the card promised, like OSC 8 links (see `showFileCard`).
+        (event) => osc8LinkHandlerRef.current?.opensFileLink(event) ?? false,
+        {
+          show: (path) => osc8LinkHandlerRef.current?.showFileCard(path),
+          hide: () => osc8LinkHandlerRef.current?.dismiss(),
+        },
+      ),
+    );
+
     term.open(containerRef.current);
 
     // Ctrl+Shift+C copies the selection with whitespace trimmed (UI padding
@@ -1235,6 +1407,7 @@ export default function TerminalView({ sessionId, active }: Props) {
       resizeObserver.disconnect();
       try { webglRef.current?.dispose(); } catch { /* may already be disposed */ }
       webglRef.current = null;
+      filePathLinks.dispose();
       term.dispose();
       termRef.current = null;
       osc8LinkHandlerRef.current = null;

app/src/components/terminal/filePathLinkProvider.test.ts

@@ -0,0 +1,70 @@
+import { describe, expect, it, vi } from "vitest";
+import { createFilePathLinkProvider } from "./filePathLinkProvider";
+
+const fakeTerm = (rows: Array<[string, boolean]>) => ({
+  buffer: {
+    active: {
+      getLine: (y: number) => rows[y] && { isWrapped: rows[y][1], translateToString: () => rows[y][0] },
+    },
+  },
+}) as unknown as Parameters<typeof createFilePathLinkProvider>[0];
+
+describe("createFilePathLinkProvider", () => {
+  it("reports 1-based inclusive ranges and activates through the gate", () => {
+    const onOpen = vi.fn();
+    const gate = vi.fn(() => true);
+    const provider = createFilePathLinkProvider(fakeTerm([["Edited src/foo.ts:42 today", false]]), onOpen, gate);
+    const links = vi.fn();
+    provider.provideLinks(1, links);
+    const [list] = links.mock.calls[0];
+    expect(list).toHaveLength(1);
+    expect(list[0].range).toEqual({ start: { x: 8, y: 1 }, end: { x: 20, y: 1 } });
+    expect(list[0].text).toBe("src/foo.ts:42");
+    list[0].activate(new MouseEvent("click"), list[0].text);
+    expect(onOpen).toHaveBeenCalledWith(expect.objectContaining({ path: "src/foo.ts", line: 42 }));
+  });
+
+  it("does nothing when the gate refuses", () => {
+    const onOpen = vi.fn();
+    const provider = createFilePathLinkProvider(fakeTerm([["src/foo.ts", false]]), onOpen, () => false);
+    const links = vi.fn();
+    provider.provideLinks(1, links);
+    links.mock.calls[0][0][0].activate(new MouseEvent("click"), "src/foo.ts");
+    expect(onOpen).not.toHaveBeenCalled();
+  });
+
+  it("spans a wrapped path across rows", () => {
+    const provider = createFilePathLinkProvider(fakeTerm([["see /workspace/p/", false], ["src/foo.ts:7", true]]), vi.fn(), () => true);
+    const links = vi.fn();
+    provider.provideLinks(2, links);
+    expect(links.mock.calls[0][0][0].range).toEqual({ start: { x: 5, y: 1 }, end: { x: 12, y: 2 } });
+  });
+
+  it("answers undefined for a row with nothing", () => {
+    const provider = createFilePathLinkProvider(fakeTerm([["plain words", false]]), vi.fn(), () => true);
+    const links = vi.fn();
+    provider.provideLinks(1, links);
+    expect(links).toHaveBeenCalledWith(undefined);
+  });
+
+  it("answers undefined for a row past the end of the buffer", () => {
+    const provider = createFilePathLinkProvider(fakeTerm([["src/foo.ts", false]]), vi.fn(), () => true);
+    const links = vi.fn();
+    provider.provideLinks(5, links);
+    expect(links).toHaveBeenCalledWith(undefined);
+  });
+
+  it("hands the hover the raw path, relative as printed (preflight P6)", () => {
+    const hover = { show: vi.fn(), hide: vi.fn() };
+    const provider = createFilePathLinkProvider(
+      fakeTerm([["Edited src/foo.ts:42 today", false]]), vi.fn(), () => true, hover,
+    );
+    const links = vi.fn();
+    provider.provideLinks(1, links);
+    const link = links.mock.calls[0][0][0];
+    link.hover(new MouseEvent("mousemove"), link.text);
+    expect(hover.show).toHaveBeenCalledWith("src/foo.ts");
+    link.leave(new MouseEvent("mouseout"), link.text);
+    expect(hover.hide).toHaveBeenCalled();
+  });
+});

app/src/components/terminal/filePathLinkProvider.ts

@@ -0,0 +1,52 @@
+/**
+ * xterm `ILinkProvider` for file paths in the buffer.
+ *
+ * Registered after `WebLinksAddon` so URLs are claimed first; `findFilePathLinks`
+ * also refuses anything inside a `scheme://` span, so the two never overlap.
+ * Ranges are 1-based on both axes with an *inclusive* end column (xterm's
+ * contract), and `provideLinks`' row is 1-based while `getLine` is 0-based.
+ */
+import type { ILink, ILinkProvider, Terminal } from "@xterm/xterm";
+import { findFilePathLinks, type FilePathMatch } from "../../lib/filePathLinks";
+import { joinWrappedRows, offsetToCell } from "../../lib/xtermLineJoin";
+
+export interface FilePathHover {
+  /** `path` is the raw matched path — relative paths stay relative. */
+  show(path: string): void;
+  hide(): void;
+}
+
+export function createFilePathLinkProvider(
+  term: Pick<Terminal, "buffer">,
+  onOpen: (match: FilePathMatch) => void,
+  gate: (event: MouseEvent) => boolean,
+  hover?: FilePathHover,
+): ILinkProvider {
+  return {
+    provideLinks(bufferLineNumber, callback) {
+      const row = bufferLineNumber - 1;
+      const line = term.buffer.active.getLine(row);
+      if (!line) return callback(undefined);
+      const joined = joinWrappedRows(term.buffer.active, row);
+      // `offsetToCell` has no row to map onto when nothing was joined.
+      if (joined.rowStarts.length === 0) return callback(undefined);
+      const matches = findFilePathLinks(joined.text);
+      if (matches.length === 0) return callback(undefined);
+      const links: ILink[] = matches
+        .map((m): ILink => ({
+          range: { start: offsetToCell(joined, m.start), end: offsetToCell(joined, m.end - 1) },
+          text: joined.text.slice(m.start, m.end),
+          decorations: { pointerCursor: true, underline: true },
+          activate: (event) => {
+            if (!gate(event)) return;
+            onOpen(m);
+          },
+          hover: () => hover?.show(m.path),
+          leave: () => hover?.hide(),
+        }))
+        // Only links that touch the row being asked about (xterm asks per row).
+        .filter((l) => l.range.start.y <= bufferLineNumber && l.range.end.y >= bufferLineNumber);
+      callback(links.length ? links : undefined);
+    },
+  };
+}