GET on the MCP endpoint returns 405

How to fix this

Respond to an HTTP GET on the MCP endpoint with 405 Method Not Allowed.

Check your own server against this rule

The validator makes real protocol requests and reports this rule as pass, warn or fail alongside the other 78. Validate a server or read how the check works.

Other Statelessness and session removal rules

• MCP-STL-001Server never mints or echoes Mcp-Session-Id
• MCP-STL-002A client-supplied Mcp-Session-Id is ignored, not required
• MCP-STL-003A cold modern request succeeds with no prior handshake
• MCP-STL-004Server does not rely on prior requests over the same connection
• MCP-STL-006DELETE on the MCP endpoint returns 405
• MCP-STL-007Last-Event-ID is ignored — streams are not resumable
• MCP-STL-008tools/list does not vary per connection