---
title: "WebMCP defined | Agent Ready Checklist"
description: "WebMCP: Browser API (W3C Community Group draft) letting a page register tools an in-browser agent can call with the user session. AR-ACT-07 (SHOULD)."
canonical: https://agentreadychecklist.com/glossary/webmcp
site: "Agent Ready Checklist"
last_updated: 2026-11-05
section: "Glossary"
---

# WebMCP defined | Agent Ready Checklist

> WebMCP: Browser API (W3C Community Group draft) letting a page register tools an in-browser agent can call with the user session. AR-ACT-07 (SHOULD).

Source: https://agentreadychecklist.com/glossary/webmcp
Site: Agent Ready Checklist
Last reviewed: 2026-11-05
Agent endpoints: https://agentreadychecklist.com/llms.txt (index), https://agentreadychecklist.com/openapi.json (API), https://agentreadychecklist.com/mcp (MCP server), https://agentreadychecklist.com/ask (search)
Access: https://agentreadychecklist.com/auth.md (no key). Pricing: https://agentreadychecklist.com/pricing.md (free).

# WebMCP

Browser API (W3C Community Group draft) letting a page register tools an in-browser agent can call with the user session. AR-ACT-07 (SHOULD). Example: if ('modelContext' in document) document.modelContext.registerTool({name:'search', description:'Search docs', inputSchema:{type:'object'}, execute: async (i) => run(i)}). Related row: AR-ACT-07 (WebMCP tools). The Verify Kit check webmcp tests WebMCP.

## Definition

Browser API (W3C Community Group draft) letting a page register tools an in-browser agent can call with the user session. AR-ACT-07 (SHOULD).

## Example

```text
if ('modelContext' in document) document.modelContext.registerTool({name:'search', description:'Search docs', inputSchema:{type:'object'}, execute: async (i) => run(i)})
```

## Where it appears on the checklist

-   [AR-ACT-07](https://agentreadychecklist.com/checklist/ar-act-07/)WebMCP tools: A product with a web UI an agent should operate registers WebMCP tools on document.modelContext; feature-detect and only ship tools that map to real actions.
-   [Guide](https://agentreadychecklist.com/guides/add-webmcp-to-a-form/)How to add WebMCP to a form

## Asked about it

### What is WebMCP and do I need it?

A browser API where the page registers tools on document.modelContext for an in-browser agent. AgentReady v2.0 made it SHOULD for products with a web UI agents operate. Feature-detect it; Chrome offers it through an early preview program.

## Sources

-   [isitagentready.com/.well-known/agent-skills/webmcp/SKILL.md](https://isitagentready.com/.well-known/agent-skills/webmcp/SKILL.md)read 2026-11-04
-   [github.com/agentready-org/standard/blob/main/CHANGELOG.md](https://github.com/agentready-org/standard/blob/main/CHANGELOG.md)read 2026-11-04

Last reviewed 2026-11-05. AgentReady v2.0, read 2026-11-04.