WebMCP Documentation

A site’s valid actions change with route, selected record, permissions, and workflow state. The published tool set should change with them. Agents should see only actions that are currently meaningful and authorized, with descriptions and schemas that match the active application context. The current registration pattern ties a tool to an AbortSignal:

const controller = new AbortController();
document.modelContext.registerTool(tool, { signal: controller.signal });

// Remove the registration during route or component cleanup.
controller.abort();

Descriptions and schemas must be replaced when application context changes; stale or duplicate registrations make discovery ambiguous. Tool-change notifications allow consumers to refresh the catalog after registration or cleanup. See Build your first React tool and the WebMCP standard API.

Transports and bridges Security and human-in-the-loop

Explanation

Architecture

Trust and status

Tool lifecycle and dynamic registration