From 0a5b1fbcd1c42578c528c8ea4574abfcb30aa2bb Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Thu, 15 Jan 2026 11:16:48 +0000
Subject: [PATCH] fix(browser): handle extension relay page selection

---
 CHANGELOG.md                                  |  1 +
 ...ge-for-targetid.extension-fallback.test.ts | 54 +++++++++++++++++++
 src/browser/pw-session.ts                     |  8 ++-
 3 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 src/browser/pw-session.get-page-for-targetid.extension-fallback.test.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 891e02ff3..6f0710458 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@
 - Browser: add `snapshot refs=aria` (Playwright aria-ref ids) for self-resolving refs across `snapshot` → `act`.
 - Browser: `profile="chrome"` now defaults to host control and returns clearer “attach a tab” errors.
 - Browser: extension mode recovers when only one tab is attached (stale targetId fallback).
+- Browser: fix `tab not found` for extension relay snapshots/actions when Playwright blocks `newCDPSession` (use the single available Page).
 - Control UI: show raw any-map entries in config views; move Docs link into the left nav.
 
 #### Plugins
diff --git a/src/browser/pw-session.get-page-for-targetid.extension-fallback.test.ts b/src/browser/pw-session.get-page-for-targetid.extension-fallback.test.ts
new file mode 100644
index 000000000..42c7e76ad
--- /dev/null
+++ b/src/browser/pw-session.get-page-for-targetid.extension-fallback.test.ts
@@ -0,0 +1,54 @@
+import { describe, expect, it, vi } from "vitest";
+
+describe("pw-session getPageForTargetId", () => {
+  it("falls back to the only page when CDP session attachment is blocked (extension relays)", async () => {
+    vi.resetModules();
+
+    const pageOn = vi.fn();
+    const contextOn = vi.fn();
+    const browserOn = vi.fn();
+    const browserClose = vi.fn(async () => {});
+
+    const context = {
+      pages: () => [],
+      on: contextOn,
+      newCDPSession: vi.fn(async () => {
+        throw new Error("Not allowed");
+      }),
+    } as unknown as import("playwright-core").BrowserContext;
+
+    const page = {
+      on: pageOn,
+      context: () => context,
+    } as unknown as import("playwright-core").Page;
+
+    // Fill pages() after page exists.
+    (context as unknown as { pages: () => unknown[] }).pages = () => [page];
+
+    const browser = {
+      contexts: () => [context],
+      on: browserOn,
+      close: browserClose,
+    } as unknown as import("playwright-core").Browser;
+
+    vi.doMock("playwright-core", () => ({
+      chromium: {
+        connectOverCDP: vi.fn(async () => browser),
+      },
+    }));
+
+    vi.doMock("./chrome.js", () => ({
+      getChromeWebSocketUrl: vi.fn(async () => null),
+    }));
+
+    const mod = await import("./pw-session.js");
+    const resolved = await mod.getPageForTargetId({
+      cdpUrl: "http://127.0.0.1:18792",
+      targetId: "NOT_A_TAB",
+    });
+    expect(resolved).toBe(page);
+
+    await mod.closePlaywrightBrowserConnection();
+    expect(browserClose).toHaveBeenCalled();
+  });
+});
diff --git a/src/browser/pw-session.ts b/src/browser/pw-session.ts
index ef8142323..671c6b01f 100644
--- a/src/browser/pw-session.ts
+++ b/src/browser/pw-session.ts
@@ -332,7 +332,13 @@ export async function getPageForTargetId(opts: {
   const first = pages[0];
   if (!opts.targetId) return first;
   const found = await findPageByTargetId(browser, opts.targetId);
-  if (!found) throw new Error("tab not found");
+  if (!found) {
+    // Extension relays can block CDP attachment APIs (e.g. Target.attachToBrowserTarget),
+    // which prevents us from resolving a page's targetId via newCDPSession(). If Playwright
+    // only exposes a single Page, use it as a best-effort fallback.
+    if (pages.length === 1) return first;
+    throw new Error("tab not found");
+  }
   return found;
 }