▶ Interactive Lab

MCP Message Flow

Walk through initialize → list_tools → call_tool → response.

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MCP uses JSON-RPC 2.0. Client and server exchange request/response/notification.

What you're seeing

Model Context Protocol: standard way for LLM apps to talk to tool servers. Built on JSON-RPC 2.0. Client calls initialize, then tools/list, then tools/call.

Transports: stdio (local), SSE (server-pushed events), HTTP (request/response). Use stdio for desktop integrations, HTTP for hosted services.

★ KEY TAKEAWAY
MCP uses JSON-RPC 2.0: initialize → tools/list → tools/call → response. Transport-agnostic.
▶ WHAT TO TRY
  • Click Next message through the 7 messages.
  • Notifications (one-way) can be sent at any time, no response expected.