WebMCP Ecosystem Adoption Tracker.

Blink

What it does

Chrome Status pencils in Chrome 157 (out 3 November 2026) as the anticipated milestone — the clearest signal yet of where this is heading. It's a target rather than a committed ship date: an origin trial is how Chrome experiments, and the official ship call comes after the trial wraps. Meanwhile you can run WebMCP in production today by signing up for the origin trial, which covers Chrome up to 156.

What to know

If you are shipping tools now, the date to watch is 20 October, when 156 — the last version the trial covers — rolls out. The formal decision is still ahead (Chrome Status marks the feature "Proposed" with standards review pending), so build on the trial and keep an eye out for the ship announcement.

For local testing: chrome://flags/#enable-webmcp-testing. Chrome Status

Blink

What it does

Microsoft runs its own origin trial, open through 17 November 2026. Register your domain and switch it on with a meta tag or an HTTP header.

What to know

Microsoft has not published which Edge version it starts in, so we are not quoting one. Being the same engine as Chrome, platform support tracks Chrome's. Trial

Blink

Desktop and Android, behind a flag, and left out of the release notes. Brave is the only browser where both halves exist at all: the API is there, and its own assistant reads it. Both sides are experimental, so see the Leo row before relying on it. Issue #55232

Open source · headless engine built for agents

What it does

Lightpanda isn't a browser people use directly — it's a headless engine you point an agent at. WebMCP is part of the engine itself, so a page can register tools and any agent hooked up to it can list them and run them. That landed in release 0.3.6 in July.

What to know

It says partial because of where Lightpanda puts the API. It still uses the old spot, navigator, not document. So if your page follows the current spec, or uses the usual compatibility shim, Lightpanda sees nothing at all. Source

Gecko

Mozilla sees the benefits but is not implementing it. Their filed concerns include the risk of a site passing an agent instructions a person would not see, and of collecting data through what people enter into tools. They have asked for the extension and automation side to be worked through first. Position

WebKit

WebKit has filed an opposing position. Their reasoning is that an agent acting for someone is closer to assistive technology such as a screen reader, and that sites should not be able to detect one and treat it differently. They have suggested the proposal be reconsidered in a new working group, beginning with a workshop at TPAC in October. Position

Agentic browsers

We found nothing either way. All are built on Chromium, so the API may be present behind the usual flag. That is not the same as the product supporting it, so we have left the row open.

Brave · assistant built into the browser

What it does

The closest thing to an everyday agent calling page tools, though it should not be read as shipped. The work was filed as an experiment, it sits behind a feature flag, and it was deliberately kept out of the release notes. When QA asked for a test plan, the Brave engineer who built it replied: "I might mark it as QA/Blocked … as it still feels very experimental." It is aimed at a 1.94 beta.

Confirmed in practice

Here is how far off it is. The code checks Chromium's own WebMCP switch before it does anything, and that switch is off unless someone turns it on. We could not find a brave://flags entry for it, or anywhere Brave turns it on for users, so as best we can tell you would have to launch the browser with a command-line switch. The injected script is written to quietly do nothing if the feature is off.

What to know

Brave separately pushes its own tool definitions into sites that never added WebMCP, so Leo can end up holding tools you did not write. That code is real and readable, and it is behind the same switch. Issue #55232

Google · assistant built into the browser

What it does

Google introduced WebMCP at I/O in May as "a proposed open web standard that allows you to expose structured tools like JavaScript functions and HTML forms to browser-based agents". That was about the standard, not about Gemini using it. We could not find any Google source, then or since, saying Gemini in Chrome consumes WebMCP tools.

How it compares

Two supporting details: Chrome's docs note that even their own WebMCP test agent, the inspector extension, is separate from Gemini in Chrome. And Chrome's agent reaches pages a different way, pointing at page elements and screen positions. I/O post

Anthropic · extension used by Claude Code, Cowork and Claude Desktop

What it does

Anthropic's docs describe how it reads a page: page text, the document, console and network messages, and screenshots. Tools your page registers are not among them.

Confirmed in practice

Confirmed in practice by someone running a site in the origin trial, whose trial registration we verified: "the extension surfaces nothing from navigator.modelContext. … Invocation works; discovery doesn't exist." It falls back to screenshots even when a page publishes tools. That request is open; an earlier one was closed by an inactivity bot rather than by a decision, and nobody from Anthropic has commented on either. Issue #76809

What to know

One row covers a lot here. Claude Code, Cowork and Claude Desktop all browse through this same extension, so none of them sees your tools either.

How it compares

And unlike the ChatGPT rows, there is no debug-protocol back door. This is a Chrome extension using its own tool surface, not a browser being driven over the debug protocol, so the trick that might work elsewhere does not apply. Anthropic's changelog does reserve a "Claude Browser" name ahead of a Claude Desktop rename, so a built-in browser pane looks close, but it is not documented yet.

OpenAI · cloud browser

What it does

OpenAI's new agent tier for longer multi-step work. When no connector fits a task, it visits public websites from a browser hosted on OpenAI's side. Nothing public says whether it can call tools a page registers.

What to know

It has real limits, in their words: "At launch, cloud browser works only on public pages. It does not accept credentials, use autofill or password managers, sign in to websites, or complete payments." So anything behind a login is out of scope for now. Docs

How it compares

This replaces two things you may be looking for: the old agent mode, now retired, and the Atlas browser, which OpenAI says stops working on 9 August 2026. Atlas notice

OpenAI · built-in browser, macOS and Windows

What it does

A real browser inside the ChatGPT app, with its own sign-ins, autofill, extensions and downloads. Both Work and Codex chats use it, and you can watch and annotate the page as it goes.

How it compares

This is the browser the debug-protocol route runs through, so the Codex row below applies here too. Switch on full CDP access in settings and your tools become reachable. Docs

OpenAI · Codex Chrome extension

What it does

For tasks needing your existing Chrome profile, signed-in sessions and open tabs.

Confirmed in practice

We tested this one ourselves. Turn on the toggle described below and the WebMCP commands are there over the debug protocol. Your tools can be listed and called.

What to know

The switch lives in ChatGPT's settings under Browser, in a section called Developer mode, and OpenAI flags it as elevated risk. Their own wording: "Allow ChatGPT to use full Chrome DevTools Protocol (CDP) access in connected Browser Use sessions. Full CDP access lets ChatGPT inspect and control sensitive browser internals that may put your data at risk." It is off until you turn it on, which is why this reads as behind a flag rather than working.

What this is not is native support. Nothing in OpenAI's docs mentions WebMCP, and we have not confirmed that ChatGPT reaches for your tools on its own rather than carrying on with screenshots. What we can say is the door is there and it opens. Docs

Perplexity · agentic browser

It reads pages through the accessibility tree and screenshots. We found no mention of WebMCP anywhere. If we have this wrong, send us a link and we will fix it.

Opera · agentic browser

Neon exposes the browser to outside tools. We are measuring the other direction here, a browser using the tools a page offers.

Browser extensions

By far the biggest audiences on this page, and no sign of WebMCP in any of them. Extensions cannot really do this yet: there is still no standard way for one to read a page's tools. See the note under Frameworks.

Browserbase · open source

Confirmed in practice

We installed the released package and ran it against current stable Chrome: it found a page's tool and called it, with no setup on our part. The methods are page.listWebMCPTools() and page.invokeWebMCPTool(), shipped in June.

What to know

Two limits worth knowing. This is TypeScript only — the published Python and Go packages have no WebMCP support, and the shorter page.tools() name people quote is on an unreleased branch. And the autonomous agent cannot see these tools at all, so prompting will not get it to use them; you call the tool API from your own code. Untested on Browserbase's rented browsers. PR #2178

Google · MCP server

One tool lists what a page offers, another runs it. You have to switch it on with --categoryExperimentalWebmcp and start Chrome with the matching feature flags, so it is off until someone does that. Once on, this is how coding agents such as Claude Code and Cursor reach your tools. Source

Google · library

Reads and runs page tools directly, and is marked experimental. It does not set the browser flag for you — you pass --enable-features=WebMCP yourself. DevTools MCP is built on this layer, so anything on Puppeteer can pick up support by upgrading. Guide

Cloudflare · cloud browser

It works, but only in their experimental --lab pool, not in production, and it reads the older version of the API. Their agents SDK does the opposite job, pushing tools into pages, so Cloudflare turns up on both sides of this. Easy to mix up. Docs

Microsoft · framework

Nothing in the code or the documentation. Someone did request it in April 2026, and a Playwright maintainer closed the request the next day as not planned, with the reasoning: "This sounds interesting. Let's see if it gains any adoption first." Nothing has changed since. Playwright sees roughly 78 million downloads a week and many agent frameworks are built on it, so this is a notable gap rather than a small one. Issue #40234

Open source · agent framework

A thorough implementation was opened on 11 February, exposing page tools as actions the agent could take directly. The pull request was closed unmerged on 12 April by the repository's inactivity bot, with no maintainer objection recorded. The current code contains no WebMCP support. PR #4085

Firecrawl · cloud agent

What it does

No WebMCP anywhere in the product or the docs. What exists is a blog post from July showing a manual recipe: because their browser endpoint runs a real browser in the cloud, an agent can script calls to a page's tools through it. Their own words for why it works: "with no special integration on Firecrawl's end."

What to know

Handy if you run a headless agent and want to reach WebMCP tools anyway. It is just not something they built. Blog post

Browserbase · cloud browser you rent

What it does

Nothing in the platform, in Director, or in their MCP server, even though Browserbase is who makes Stagehand.

What to know

And it is worse than just undocumented. Stagehand only switches WebMCP on when it starts a browser on your own machine. Browserbase's rented sessions give you settings for things like screen size, proxies and stealth, but no way to pass browser start-up flags at all — and their docs never say which Chrome version they run, only that they patch it automatically. So there is no route to WebMCP on their cloud today. Session API