WebMCP
A W3C-draft standard that lets a web page expose callable tools to a visiting agent via the navigator.modelContext browser API, bringing MCP into the browser.
- term
- WebMCP
- category
- protocols
- short_def
- A W3C-draft standard that lets a web page expose callable tools to a visiting agent via the navigator.modelContext browser API, bringing MCP into the browser.
- long_def
- Instead of an agent screenshotting a page and guessing where to click, a WebMCP-enabled page declares its capabilities as typed tools the agent can invoke directly through navigator.modelContext. Published as a W3C Draft Community Group Report on 10 February 2026 (developed in the Web Machine Learning Community Group) and available as an early preview in Chrome 146.
- see_also
mcpaccessibility-tree- etymology_origin
- Proposed jointly by Google and Microsoft engineers (unified proposal August 2025); accepted into the W3C Web Machine Learning Community Group September 2025; published as a Draft Community Group Report on 10 February 2026. Note: the browser API is navigator.modelContext (the prior document.modelContext naming is superseded).
- related_to
mcpaccessibility-treeagentic-web- contrast_with
- Unlike MCP, which connects an agent to a remote server, WebMCP exposes tools in-browser via navigator.modelContext — it is the in-browser sibling of MCP, not a server protocol.
- example
- WebMCP shipped as an early preview in Chrome 146 (February 2026), following its W3C Draft Community Group Report dated 10 February 2026.
- source
- https://www.w3.org/community/webml/
- status
- draft
- why_it_matters
- WebMCP lets any website turn its existing UI into agent-callable tools without a separate server, lowering the bar for in-browser agent-readiness.
- sameAs
- —
- bridge_entity
- protocols/capability/webmcp
- last_verified
- 2026-06-15
- md_twin
- /glossary/webmcp.md