Agents ask too (WebMCP)

WebMCP is an emerging browser API that lets AI assistants (such as ChatGPT Desktop) discover and call structured tools defined on a web page — instead of reading raw HTML. When a supporting agent browses a website with AskVio installed, it can call ask_site, search_site, and get_source to query your official knowledge base directly.

AI assistants increasingly browse and shop on behalf of your customers. With WebMCP they get the same first-party answers your visitors do, and their questions land in the same reports: what agents asked, what your site couldn't answer and which products they looked for appear in Intelligence next to human questions (use the Agent only filter to see them alone). Agent questions count towards your monthly question limit; when the site is over its limit, agents get a 402 quota_exceeded response.

What gets registered

AskVio registers three tools on document.modelContext (the browser API surface):

Tool	What it does	Controlled by
`ask_site`	Answers a natural-language question from your indexed knowledge.	Ask questions toggle
`search_site`	Returns a ranked list of relevant pages and source links.	Search knowledge toggle
`get_source`	Retrieves the indexed text for a specific page URL.	Always registered when WebMCP is enabled

Browser support status

WebMCP is an emerging, limited-availability API. As of late 2026 the confirmed clients are:

ChatGPT Desktop — native support, no origin trial required
Brave Leo — experimental support
Chrome 149+ — available via the Chrome origin trial (requires customer origin enrollment)
Edge 150+ — available via the Edge origin trial

Standard browser ChatGPT or Claude tabs do not load page-defined WebMCP tools — only a desktop agent or origin-trial build does. AskVio feature-detects document.modelContext and leaves the normal widget untouched in unsupported environments.

How to enable

In your AskVio dashboard, go to Security → AI Agent Access.
Switch Enable WebMCP on.
In the Websites allowed to expose AskVio tools field, enter the exact HTTPS origins where the widget is installed — one per line, e.g. https://www.example.com. Do not include paths or wildcards.
Choose which tools to allow: Ask questions and Search knowledge are on by default.
Optionally toggle Track AI-agent interactions to control whether these queries appear in your analytics.
Click Save WebMCP settings. Changes take effect immediately — no republish required.

Note: This setting lives outside the normal test/prod publishing workflow. It applies to your production widget as soon as you save.

No extra installation required

If you already have the AskVio widget script on your site, no additional markup is needed. The widget fetches an origin-bound signed token on page load and registers the tools automatically once document.modelContext is available. If the browser does not support WebMCP, nothing changes for human visitors.

How Chrome and Edge origin trials work

Chrome 149+ and Edge 150+ require a valid origin-trial token served from the customer's own origin. AskVio cannot obtain or serve this token for an arbitrary customer domain from a third-party widget script. Until the API ships natively in those browsers, origin-trial builds require the customer to:

Register at the Chrome Origin Trials portal for the WebMCP trial.
Add the returned token to their site's HTTP response headers or a <meta> tag.

ChatGPT Desktop requires no token — it is the primary recommended client.

Verifying registration

Open the browser console on your customer page (not on chatgpt.com) and run:

// Is the API present?
document.modelContext

// What did AskVio register?
AskVio.getWebMcpStatus()

// What tools does the browser see?
await document.modelContext?.getTools()

The status object can be in one of these states:

disabled — WebMCP is off in your dashboard settings.
configuration_error — WebMCP is on but this origin is not in your allowlist, or the signing secret is missing.
waiting_for_browser — the widget is waiting up to 2 seconds for document.modelContext to appear.
unsupported_browser — document.modelContext is absent; tools cannot be registered.
registered — tools are active. The tools array lists their names.
error — registration failed; check the [AskVio WebMCP] console entries.

Security and rate limits

Tenant identity comes from a signed, origin-bound token issued at widget load time. Any clientId in the request body is ignored.
The request origin, token origin, and your allowlist must all match exactly.
Only public knowledge is exposed. Private or authenticated content is not accessible via WebMCP.
Questions are capped at 2,000 characters; results at 10 per search.
Traffic defaults to 60 requests per minute per site per origin. Contact support to raise this limit.
Each query has a 20-second server-side timeout.
WebMCP can be disabled independently of the human widget without redeploying your site.

Analytics

Every WebMCP tool call is recorded as a separate analytics event with interface: "webmcp" and actorType: "agent". You can view agent traffic in the Analytics → AI Agent Traffic section of your dashboard, which shows total queries, unique sessions, no-answer rate, average latency, channel breakdown, top questions, top intents, and top sources.

If you have Google Tag Manager on your site, AskVio pushes the following events to window.dataLayer from the widget during a WebMCP session:

askvio_agent_query
askvio_agent_search
askvio_agent_no_answer
askvio_agent_query_error

AskVio's own Firestore store is the canonical analytics record. GA4 events are supplementary and do not fabricate a pageview or browser session.