This should reduce the flakiness and issue with finding open DevTools
tabs for the corresponding pages.
Currently we do multiple loops over all the targets, so this should have
a nice performance improvement when multiple pages are opened.
With a fallback for older versions.
This should reduce the flakiness and issue with finding open DevTools
tabs for the corresponding pages.
Currently we do multiple loops over all the targets, so this should have
a nice performance improvement when multiple pages are opened.
This PR implements the ability to trigger an extension action by passing
it an extension id.
It uses puppeteer internals and the canary chrome version in tests since
the TriggerAction CDP command is still not available in the current
stable release.
- reduces the token usage.
- makes emulation and script compatible with CLI.
- documents .nullable() and .object() restrictions for the future.
- the emulation tools do not have nullable anymore and undefined would
clear the emulation instead. The model is thus required to provide all
emulation settings at once.
Closes https://github.com/ChromeDevTools/chrome-devtools-mcp/issues/918
- renamed getSelectedPage to getSelectedPptrPage
- removes getSelectedPptrPage from tool interfaces
- moves dialog handling to McpPage
- makes responses to be optionally McpPage-scoped
## Summary
Adds optional `pageId` routing to page-scoped tools, gated behind
`--experimental-page-id-routing`. When enabled, multi-agent callers can
target a specific page without relying on global selection state. Fully
backward-compatible: without the flag, behavior is unchanged.
### Key changes
- **`pageScoped` annotation**: tools declare `pageScoped: true`; the
server merges `pageId` into their schema at registration time (when the
flag is on)
- **`McpPage` wrapper**: consolidates per-page state (numeric id,
isolated context name, focus tracking) into a single class
- **Request-scoped page routing**: `resolvePageById()` resolves the
target page, `setRequestPage()` threads it through the handler so tools
like `getSelectedPage()` see the right page
- **`assertPageIsFocused`**: keyboard/input tools validate that the
target page holds browser focus, returning an actionable error ("call
select_page first") instead of silently dispatching to the wrong page
- **`--experimental-page-id-routing` CLI flag** (hidden): gates schema
injection and request-scoped routing so the feature can be tested before
graduating
- **Eval scenarios**: `page_id_routing_test` and
`page_focus_keyboard_test` with `serverArgs` support in the eval harness
Addresses #1019
## Summary
Enhances wait_for to support waiting on multiple possible texts and
resolve when any one appears.
This addresses long-running flows that can end in different UI outcomes
(for example, "Complete" or "Error"), avoiding unnecessary 300s waits
when only one expected string is provided.
Closes#916.
## Tool Update
### wait_for
Waits for text on the selected page, now with any-match support.
| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| text | string \| string[] | yes | A single text or a non-empty list of
texts. Resolves when any value appears. |
| timeout | integer | no | Maximum wait in ms (0 keeps default
behavior). |
---
## Design / Implementation
- Kept backward compatibility: existing single-string text calls
continue to work unchanged.
- Added schema support for string | string[] with non-empty array
validation.
- Updated context API to accept string | string[].
- Matching logic now normalizes to an array and races all candidates
across all frames using both:
- aria/<text>
- text/<text>
- Added clearer response output for array input:
- Element matching one of ["Complete","Error"] found.
- Updated generated tool docs for the new wait_for contract.
- Improved docs generation to render ZodUnion types (so union params are
documented correctly, not as unknown).
---
## Tests
Added/updated coverage for:
- Schema acceptance of:
- single string
- non-empty string array
- rejection of empty array
- Any-match array success case
- Any-match array when matching text appears later (async/delayed
content)
- Existing wait_for behavior remains covered for single-text usage
Executed relevant test suites:
- tests/tools/snapshot.test.ts
- tests/McpContext.test.ts
- tests/index.test.ts
Confirmation after the change applied:
https://opncd.ai/share/8m6I4r4a
## Summary
Adds storage-isolated browser contexts via an optional `isolatedContext`
parameter on the `new_page` tool, following the simplified design
proposed by @OrKoN in #926.
Pages created with the same `isolatedContext` name share cookies,
localStorage, and storage. Pages in different isolated contexts (or the
default context) are fully isolated — ideal for testing multi-user
real-time features like chat, notifications, or collaborative editing.
## Changes
### `new_page` tool
- New optional `isolatedContext: string` parameter
- If specified, creates/reuses a named `BrowserContext` and opens a page
in it
- If omitted, uses the default browser context (existing behavior
unchanged)
### `McpContext`
- `#isolatedContexts` Map: LLM-provided names → Puppeteer
`BrowserContext` instances
- `#pageToIsolatedContextName` WeakMap: GC-safe page → context name
reverse lookup
- Auto-discovery: externally created browser contexts get
`isolated-context-1`, `isolated-context-2`, etc.
- `getIsolatedContextName(page)`: returns the isolated context name for
a page (used by response formatting)
- `page.browserContext()` used for context membership detection (no
custom target event forwarding needed)
- No context cleanup in `dispose()` or `closePage()` — either the entire
browser is closed or we disconnect without destroying state
### `McpResponse`
- Page list includes `isolatedContext=${name}` labels (both text and
structured JSON output)
### `ToolDefinition`
- `Context` interface extended with `getIsolatedContextName(page)`
method
## What's NOT included (by design)
- **No `TargetEventEmitter`**: Puppeteer forwards target events from
`BrowserContext` → `Browser` internally
- **No context cleanup**: Browser contexts are not closed on `dispose()`
or page close, per maintainer guidance
- **No `about:blank` cleanup**: Default context and isolated contexts
coexist side-by-side
## Example
```
> new_page url="https://app.example.com/chat" isolatedContext="userA"
> new_page url="https://app.example.com/chat" isolatedContext="userB"
> list_pages
Page 1: [app.example.com/chat] isolatedContext=userA
Page 2: [app.example.com/chat] isolatedContext=userB [selected]
```
Pages in different isolated contexts have fully independent cookies,
localStorage, IndexedDB, and WebSocket connections.
## Tests
- 6 new tests covering `isolatedContext` feature in
`tests/tools/pages.test.ts`
- All existing tests pass (333+)
- Zero type errors, lint clean
Closes#926
---------
Co-authored-by: Alex Rudenko <alexrudenko@chromium.org>
## Summary
Adds `screencast_start` and `screencast_stop` MCP tools that allow
agents to record a video of a page using Puppeteer's `page.screencast()`
API.
Only enabled if the command line option `--experimental-screencast` is
provided
Closes#878.
## New Tools
### `screencast_start`
Starts recording a screencast (video) of the selected page in mp4
format.
| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `path` | string (optional) | temp file | Output file path |
### `screencast_stop`
Stops the active recording and reports the saved file path.
## Design
- **Start/stop pair** following the `performance_start_trace` /
`performance_stop_trace` pattern
- **State management** via `getScreenRecorder()` / `setScreenRecorder()`
on the Context interface
- **Category**: `DEBUGGING` (alongside `take_screenshot`)
- **ffmpeg dependency**: Clear error message when ffmpeg is not
installed
- **Temp file fallback**: When no `path` is provided, creates a temp
file with the correct extension
---------
Co-authored-by: Alex Rudenko <alexrudenko@chromium.org>
We upgrade the performance trace tools to include real-user experience
data from the Chrome User Experience Report (CrUX).
https://developer.chrome.com/docs/cruxhttps://developer.chrome.com/docs/crux/methodology
### Deets
* When a trace is stopped, the server now extracts the primary
navigation URLs from the trace (determined by insightSets).
* It calls the public CrUX API to fetch field metrics (LCP, INP, CLS)
for each unique URL/Origin.
* The formatting of crux data is handled by upstream TraceFormatter, but
it looks like this:
```md
Metrics (field / real users):
- LCP: 2595 ms (scope: url)
- LCP breakdown:
- TTFB: 1273 ms (scope: url)
- Load delay: 86 ms (scope: url)
- Load duration: 451 ms (scope: url)
- Render delay: 786 ms (scope: url)
- INP: 140 ms (scope: url)
- CLS: 0.06 (scope: url)
- The above data is from CrUX–Chrome User Experience Report. It's how the page performs for real users.
- The values shown above are the p75 measure of all real Chrome users
- The scope indicates if the data came from the entire origin, or a specific url
- Lab metrics describe how this specific page load performed, while field metrics are an aggregation of results from real-world users. Best practice is to prioritize metrics that are bad in field data. Lab metrics may be better or worse than fields metrics depending on the developer's machine, network, or the actions performed while tracing.
```
**Privacy Considerations:**
* Updates the server README to inform users that performance analysis tools may send trace URLs to the Google CrUX API.
* Adds a notification message to the server startup logs regarding the CrUX API interaction.
Doc: go/crux-in-bifrost
Fixes b/446630695
---------
Co-authored-by: Alex Rudenko <alexrudenko@chromium.org>
Co-authored-by: Alex Rudenko <OrKoN@users.noreply.github.com>
Note that we replace the existing "pageerror" handler with our new
`UncaughtError` handler. The latter has a structured stack trace
attached which we can source map via DevTools.
This regresses the current functionality slightly, as we lose
"pageerror"s for workers and oopif.
## Summary
- Add `background` boolean parameter to the `new_page` tool
- When set to `true`, the new page opens in the background without
bringing it to the front
- Uses Puppeteer's existing `background` option for `browser.newPage()`
Fixes#826
---------
Co-authored-by: Alex Rudenko <OrKoN@users.noreply.github.com>
Co-authored-by: Alex Rudenko <alexrudenko@chromium.org>
previously, Chrome DevTools MCP was strictly requiring the client to use
the latest snapshot. This change updates the behavior to be more
lenient. Previously issued uids will be recognized if the underlying
backend Id (loaderId + backendNodeId) still exists.
Related https://github.com/ChromeDevTools/chrome-devtools-mcp/issues/726
This is the stack trace of the console message itself. If the argument
is an Error object or an "Error.stack" like string we don't do anything
special (yet).
The stack trace is source mapped if source maps are available.
The function matches the target ID of the console message to the
`SDK.Target` of DevTools. The only oddity is that DevTools works in a
lazy manor: It creates stack traces upfront and as source maps come in,
stack traces get updated. This does not work for the MCP server.
Instead, we wait for script parsed events and source maps to attach
before creating the stack trace. Since this could take potentially a
while, we guard it with a time out.
bringToFront() not only brings the tab to front in the browser but also
the browser window itself. This PR fixes the issue by making the call to
bringToFront() optional allowing agents to bring a tab to the user's
attention if needed but not always. To mitigate the risk of selected
page that is in the background being throttled, this PR implements
emulation of the focused page to make background tabs run as usual.
Small cleanup PR that uses the result of `createPagesSnapshot` and
passes it to the two collector instances. This way, we consistently
apply the `Page[]` filtering done by `createPagesSnapshot` and we don't
have to forward the `experimentalIncludeAllPages` option to all
collectors.
This PR prevents license notices being dropped when creating package for
publication.
This can happen when first import in the file is type-only import that
gets removed during build. When there is no empty line between the
license block comment and such import, the comment is treated as related
to the import and gets removed alongside it.
Adding an empty line between copyright notice and the import fixes the
issue.
Co-authored-by: Piotr Paulski <piotrpaulski@chromium.org>
- fixes a memory leak introduced previously (I could not pinpoint it but
McpContext was retained for subsequent tests).
- adds a test that issue continue being aggregated on reload.
- moves page-specific logic to a class.
Nikolay Vitkov