What changed, and when.
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- NLWeb WebMCP MCP A2A
Reference page v0 — verified June 2026
The reference is live. Every protocol claim — origins, runtime locations, and boundaries — was checked against the canonical docs on this date. The decision table is the page to bookmark.
Next up: the demo repo that wires NLWeb and WebMCP into a single site, which backs the “Common pitfalls” section once the pitfalls have actually been hit.
- WebMCP
WebMCP enters origin trial in Chrome 149
WebMCP moved from independent library to a proposed W3C standard with Chrome implementing natively. The origin trial exposes two APIs:
- Imperative — register tools in JavaScript via
navigator.modelContext. - Declarative — annotate HTML forms so the agent can operate them directly.
Access is gated by the
toolsPermissions Policy. Because it’s browser-only, agents must visit the page before they can use any of it — pair it with NLWeb if you also need to be discoverable. - Imperative — register tools in JavaScript via