Skip to main content
document.modelContext belongs to the evolving WebMCP Community Group proposal. Use the source that owns the behavior you need.

​
Platform and implementation sources

The proposal and browser implementations can differ while changes land. Use the Community Group draft for the proposed API, and use implementation docs and tests for browser compatibility.

​
MCP-B package behavior

MCP-B package references describe the code shipped by this project. They do not redefine the proposal. MCP-B preserves some compatibility surfaces that differ from the live draft. The upstream webmcp-types package provides ambient proposal declarations; the scoped @mcp-b/webmcp-types package adds MCP-B schema inference and compatibility types. They are separate packages. Use WebMCP and MCP-B extensions for the boundary and Choose a runtime for package selection.