JSON-RPC method reference

Zambo MCP uses JSON-RPC 2.0 over HTTP POST. Send requests to https://zambo.dev/api/mcp with JSON content.

initialize

{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"your-client","version":"1"}}}

The result announces the server, the focused default catalog, and agent instructions. The instructions point to the verifiable receipt contract and the universal entry point.

tools/list

{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}

The default response is the focused catalog. A full catalog is an explicit opt-in and should not be fetched by a cold client unless it needs the complete list.

tools/call

{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"live_price","arguments":{"symbol":"BTC"}}}

Successful results include content and a receipt object. Keep the receipt ID and link with the answer. Errors preserve JSON-RPC error codes and structured data.

Error codes

• -32600 invalid JSON-RPC request.
• -32602 invalid tool arguments; data.issues identifies fields and may include an example call.
• 402 quota or payment required; inspect usage and the payment contract.
• 429 velocity or provider throttling; retry after the returned delay without treating it as a purchase request.

Receipt verification

For a receipt ID, request GET /api/receipt/<id>/verify. The public HTML handoff is /run/<id>.

Connect the endpoint →