Requests, Responses & Notifications
The three message shapes MCP exchanges all day.
Three Shapes of Talk
Under the hood, MCP speaks JSON-RPC. Every exchange is just one of three message shapes, and once you know them the wire stops feeling like magic.
What Is a Request?
A request asks the other side to do something and expects an answer. It carries an id so the reply can be matched back to it later.
{"jsonrpc": "2.0", "id": 1, "method": "tools/list"}All lessons in this course
- Requests, Responses & Notifications
- Anatomy of a JSON-RPC Call
- The Initialize Handshake
- Reading Errors in the Wire