Charles JonesClaims on this page come from the vendors’ own documents, stored and hash-verified. Where something is not in those documents, this page says so instead of repeating it.
The standard
- Accepted by the W3C Web Machine Learning Community Group, September 2025.
- A Chrome origin trial is live — a time-limited programme giving sites early access before a feature ships broadly.
- Native support in Chrome and Edge is targeted for the second half of 2026.
The API, as documented
The interface is document.modelContext. A page registers a tool with registerTool, and
getTools() discovers what has been registered.
Use registerTool to add a single tool to the model context.
One correction worth recording, because we made it ourselves: an earlier plan of ours carried the
name navigator.modelContext. That name appears in none of the vendor documents we hold. We
had it wrong, we checked, and we changed it. Anything on this site that reads like an API fact and
cannot be traced to a stored document gets the same treatment.
Similarly, a widely-repeated claim that the older name was deprecated in Chrome 150 is not present in the documents we hold. We carry it as unverified rather than stating it.
Adoption, measured rather than assumed
Across the business sites we crawled, WebMCP appears in the page itself for a small fraction, and tools are exposed at all for not much more. The counts and the shares are in the table below, rendered from the crawl rather than typed here.
It is overwhelmingly platform-shipped — Wix and Shopify — and it is not entirely so. The table carries the remainder rather than rounding it away, because “all of it is a platform” was the claim this page used to make and the crawl does not support it.
Source — fleet crawl, 2026-08-28, rendered from the snapshot below.
So the honest summary is not “everyone is adopting this.” It is that a couple of large platforms have begun switching it on for their own tenants, and independent sites are not doing it at all.
Fleet crawl · 2026-08-28 · 27,112 crawled
| Sites crawled | 27,112 |
| WebMCP in the page itself2.6% of all crawled | 713 |
| Exposing tools at all8.9% of all crawled — in the page, or advertised in an llms.txt | 2,404 |
| Of those, shipped by Wix or Shopify | 2,311 |
| Of those, neither Wix nor Shopifyso it is overwhelmingly platform-shipped, but not entirely | 93 |
| Could not judgenever reached; absence here is not evidence of absence | 1,634 |
SNAPSHOT 2026-09-04T01:47:53Z · measured 2026-09-03T03:25:55Z · bq query --dry_run then --nouse_legacy_sql over agent_ready.crawl_v1 (frozen, 27,112 rows) · rate = invisible / JUDGED, where judged excludes UNREACHABLE and CRAWLER_ERROR (agent_invisible IS NULL, tools/fleet_crawl.py:342) · receipt receipts/crawl_v1-census.json