# 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.

_The Agentic Web Lexicon · /glossary/webmcp · [JSON](/api/glossary/webmcp) · [all The Agentic Web Lexicon](/glossary)_

- **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:** mcp, accessibility-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:** mcp, accessibility-tree, agentic-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