What is JSON-RPC 2.0?
The small remote-procedure-call format MCP uses: requests with jsonrpc, id, method and params; responses with the same id and either result or error.
A notification is a request without an id, which expects no response (MCP's notifications/initialized is one). Standard error codes include -32700 (parse error), -32600 (invalid request), -32601 (method not found) and -32602 (invalid params).
Sources
Related terms
- Model Context Protocol (MCP)An open protocol, introduced by Anthropic in November 2024, that lets AI applications connect to external tools and data through a standard interface.
- Tool call (tools/list, tools/call)How an AI model uses an MCP tool: the client lists the server's tools with tools/list, the model picks one, and the client runs it with tools/call and returns the result to the model.