Model Context Protocol

Connect an agent to SignalHarness MCP

The MCP endpoint exposes free service discovery plus paid invocation routing for the same 330 canonical services. HTTP and MCP use the same IDs, prices, Base USDC requirements, verification, settlement, receipts, and recovery controls.

Connection

Transport: JSON-RPC 2.0 over HTTPS POST
Endpoint: https://signalharness.ai/api/agent/services/mcp

curl -i -X POST https://signalharness.ai/api/agent/services/mcp \
  -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"signalharness-quickstart","version":"1.0.0"}}}'

Discover tools

After initialization, call tools/list. Use list_services and get_service for free discovery. invoke_service resolves the canonical paid endpoint and returns its x402 challenge; it does not grant spending authority.

curl -i -X POST https://signalharness.ai/api/agent/services/mcp \
  -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}'

Payment-client requirements

x402 V2 exact EVM support for eip155:8453.
A signer capable of authorized Base USDC payments.
Explicit per-call and cumulative spending controls.
Validation of URL, method, amount, asset, recipient, expiry, and request body before signing.
Support for PAYMENT-REQUIRED, PAYMENT-SIGNATURE, and PAYMENT-RESPONSE.
Same-payment recovery on ambiguous transport outcomes.

Client configuration

Point the client at the HTTPS endpoint above. Do not configure Solana payment schemes for SignalHarness: service calculations may process caller-supplied Solana data, but customer payment remains Base USDC. Keep wallet secrets in a server-side secret store, never in an agent prompt or browser bundle.

Run the HTTP quickstart · OpenAPI · well-known resource list