feat(cli): shut idle headless sessions down after an hour by yury-s · Pull Request #42676 · microsoft/playwright

Yury Semikhatsky (yury-s) · 2026-09-11T17:15:34Z

Summary

A CLI session whose browser is headless and launched by Playwright now shuts itself down after an hour without commands, the same way close does, so a session an agent never closed stops holding a browser. Headed and attached browsers are left alone.
The MCP server applies the same default, closing the browser and launching a new one on the next tool call.
--idle-timeout <ms> on open, attach and the MCP server overrides the default in any mode, 0 disables it. Also settable as timeouts.idle in the config file or PLAYWRIGHT_MCP_IDLE_TIMEOUT. The MCP option was named --timeout-idle in 1.64.0-next and is renamed here before it ships.
IdleTimer gains poke(), called when a tool call starts and once when a CLI session is ready, which covers a session that never receives a command.

Pavel Feldman (pavelfeldman)

I think this should bubble up from the tools/backend/Context. It should self-destruct upon inactivity, which will be destroying backend server.

github-actions · 2026-09-11T20:04:26Z

🟢 CI is clear — the one failure is a pre-existing Firefox flake

Hi, I'm the Playwright bot and I took a first look at the failing check.

The latest merge report (run 34641795387) has a single failure, [firefox] › mcp/cli-core.spec.ts:123 › select, and it's a known Firefox-only flake — not something this PR caused. This PR only wires up idle-session shutdown (idleTimer.ts, cli-daemon/*, mcp/program.ts, mcp/config.ts); the failing test just performs a CLI select and never touches idle timeouts.

Details

Pre-existing flake / infra

[firefox] › mcp/cli-core.spec.ts:123 › select — rare Firefox-only flake. Across the test-results DB it fails only on firefox (2 of 716 runs; 0 failures on chromium/chrome/msedge/webkit over 700+ runs each) and both failures are on SHAs this PR can't be responsible for: a push on main (sha a5e5632, run 33913247836, 2026-09-04) and PR feat(ui-mode): update individual snapshots #42421 (sha f4dc9b9, run 32992366860, 2026-08-26) — both before this branch. This PR's diff is scoped to the idle-timeout shutdown path, which the CLI select flow doesn't exercise, and a Firefox-only failure in code the PR didn't change for that engine reinforces the flake read. Note the earlier runs on this same PR failed different tests (mcp/cli-core.spec.ts:262, mcp/annotate.spec.ts, mcp/cli-devtools.spec.ts:173) that then passed — churn across reruns is itself a flake tell.

_{Triaged by the Playwright bot - agent run}

The daemon now honors timeouts.idle and defaults it to one hour for headless browsers it launched, exiting the same way `close` does. Headed and attached browsers keep running unless a timeout is set explicitly. `open --idle-timeout=<ms>` overrides the default and 0 disables it. The MCP server gets the same default, and its option is renamed to --idle-timeout to match. Fixes microsoft/playwright-cli#460

Drops the running-call bookkeeping: a tool call is expected to be short relative to the timeout, so restarting the countdown when the call starts is enough and removes the callTool wrapper.

Also drops unref(): both the MCP server and the CLI daemon exit through process.exit(), so the timer never decides whether the process lives.

github-actions · 2026-09-11T23:03:05Z

Test results for "MCP"

8509 passed, 1436 skipped

Merge workflow run.

## What's New ### 🎉 New Tools - **`browser_webmcp_list` / `browser_webmcp_call`** — List and call the tools a page registers through the [WebMCP](https://webmachinelearning.github.io/webmcp/) API, letting the page do the work instead of driving its UI. When a page has WebMCP tools, the page status reports how many are available ([#42613](microsoft/playwright#42613)). WebMCP is experimental, see [WebMCP in Chrome](https://developer.chrome.com/docs/ai/webmcp) for how to enable it. ### Other Changes - New `--profile-dir-name <name>` option (env `PLAYWRIGHT_MCP_PROFILE_DIR_NAME`) selects the Chrome profile to connect to in extension mode when the extension is installed in several profiles, for example `"Profile 1"` ([#42527](microsoft/playwright#42527)) - Headless browsers launched by the server are now closed after one hour without tool calls; the next tool call launches a new one. Use `--idle-timeout <ms>` (config `timeouts.idle`, env `PLAYWRIGHT_MCP_IDLE_TIMEOUT`) to change the timeout, `0` disables it. Headed and attached browsers are not closed unless a timeout is set explicitly ([#42663](microsoft/playwright#42663), [#42676](microsoft/playwright#42676)) - `--image-responses` accepts `only`: a response that carries an image consists of the image parts alone, without the text part ([#42672](microsoft/playwright#42672)) ## Bug Fixes - `browser_close` returns an error when the browser context is shared (`--shared-browser-context`) instead of breaking the calling client's session. This supersedes the v0.0.80 change that dropped the backend after `browser_close` ([#42495](microsoft/playwright#42495)) - With `--shared-browser-context`, `browser_start_recording` / `browser_stop_recording` (opt-in via `--caps=devtools`) keep each client's recording separate instead of delivering one client's recorded actions to another ([#42622](microsoft/playwright#42622), [#42627](microsoft/playwright#42627)) - The file access check follows symlinks, so a symlink inside the workspace can no longer be used to read or write files outside the allowed roots ([#42628](microsoft/playwright#42628)) - Explicitly named output files in a nested directory (e.g. `sub/shot.png`) no longer fail with `ENOENT`; `browser_file_upload` and `browser_drop` resolve relative paths against the workspace root ([#42540](microsoft/playwright#42540)) - In extension mode with `PLAYWRIGHT_MCP_EXTENSION_TOKEN` set, a connection that never completes (e.g. the token belongs to another Chrome profile) now fails after 30 seconds with a hint instead of hanging the tool call forever ([#42525](microsoft/playwright#42525)) - Disable the Chromium sandbox by default on Linux for the bundled Chromium build, which lacks the setuid sandbox helper ([#42490](microsoft/playwright#42490))

## What's New ### 🎉 New Commands - **`webmcp-list` / `webmcp-call`** — List and call the tools a page registers through the [WebMCP](https://webmachinelearning.github.io/webmcp/) API, letting the page do the work instead of driving its UI. When a page has WebMCP tools, the page status reports how many are available ([#42613](microsoft/playwright#42613)). WebMCP is experimental, see [WebMCP in Chrome](https://developer.chrome.com/docs/ai/webmcp) for how to enable it. ### Other Changes - Headless sessions now shut down after one hour without commands, so a session an agent never closed no longer holds a browser; run `open` again to start a new one. Use `open --idle-timeout <ms>` (config `timeouts.idle`, env `PLAYWRIGHT_MCP_IDLE_TIMEOUT`) to change the timeout, `0` disables it. Headed browsers stay open, and attached browsers are only detached when `attach --idle-timeout <ms>` is set ([#42676](microsoft/playwright#42676)) - The skill includes a guide for attaching screenshots and videos to pull requests with `gh --attach` ([#42645](microsoft/playwright#42645)) ## Bug Fixes - Session daemons exit when their control socket is deleted or replaced, instead of staying alive with the browser ([#42454](microsoft/playwright#42454)) - Explicitly named output files in a nested directory (e.g. `screenshot --filename=sub/shot.png`) no longer fail with `ENOENT` ([#42540](microsoft/playwright#42540)) - Video chapters and screencast overlays are no longer hidden behind open dialogs and popovers ([#42642](microsoft/playwright#42642)) - `npx playwright test --debug=cli` works for tests that create more than one browser context and for every test in a worker, not just the first ([#42503](microsoft/playwright#42503)) - With `PLAYWRIGHT_MCP_EXTENSION_TOKEN` set, `attach --extension` fails after 30 seconds with a hint when the extension never connects (e.g. the token belongs to another Chrome profile) instead of hanging forever ([#42525](microsoft/playwright#42525)) - Disable the Chromium sandbox by default on Linux for the bundled Chromium build, which lacks the setuid sandbox helper ([#42490](microsoft/playwright#42490)) ## Upgrading ```bash npm install -g @playwright/cli@0.1.20 ```

Pavel Feldman (pavelfeldman) reviewed Sep 11, 2026

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Yury Semikhatsky (yury-s) force-pushed the fix-cli-460 branch from 43250e6 to 5d88965 Compare September 11, 2026 19:13

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Yury Semikhatsky (yury-s) added 2 commits September 11, 2026 14:38

chore: drop comments from the idle timer

71acf89

Yury Semikhatsky (yury-s) force-pushed the fix-cli-460 branch from 5d88965 to 71acf89 Compare September 11, 2026 21:39

Pavel Feldman (pavelfeldman) approved these changes Sep 11, 2026

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chore(mcp): reset the idle timer at the start of each call

428f9ec

Drops the running-call bookkeeping: a tool call is expected to be short relative to the timeout, so restarting the countdown when the call starts is enough and removes the callTool wrapper.

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chore(mcp): rename the idle timer reset to poke

d15e949

Also drops unref(): both the MCP server and the CLI daemon exit through process.exit(), so the timer never decides whether the process lives.

Yury Semikhatsky (yury-s) merged commit 3b346c8 into microsoft:main Sep 11, 2026
17 checks passed

Yury Semikhatsky (yury-s) deleted the fix-cli-460 branch September 11, 2026 22:51

github-actions Bot mentioned this pull request Sep 11, 2026

feat(mcp): add media emulation #42668

Merged

JustasM (JustasMonkev) mentioned this pull request Sep 12, 2026

Evaluate upstream --timeout-idle (close primary browser after inactivity) for parity with existing session reaper JustasMonkev/mcp-accessibility-scanner#221

Closed

This was referenced Sep 12, 2026

[Bug]: MCP idle timeout closes the browser during a tool call that outlasts it, failing that call #42693

Open

fix(mcp): do not close browser while tool call is running #42696

Open

This was referenced Sep 14, 2026

chore: mark v0.0.81 microsoft/playwright-mcp#1751

Merged

chore: mark v0.1.20 microsoft/playwright-cli#467

Merged

github-actions Bot mentioned this pull request Sep 15, 2026

Update Playwright MCP upstream to v0.0.81 swimmwatch/cloakbrowser-mcp#143

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feat(cli): shut idle headless sessions down after an hour - #42676

feat(cli): shut idle headless sessions down after an hour#42676
Yury Semikhatsky (yury-s) merged 4 commits into
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github-actions Bot commented Sep 11, 2026

🟢 CI is clear — the one failure is a pre-existing Firefox flake

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Test results for "MCP"

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Yury Semikhatsky (yury-s) commented Sep 11, 2026 •

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