{"openapi":"3.0.0","info":{"title":"Agent Audit Trail","version":"1.0.0","description":"Creates tamper-evident, HMAC-signed audit log entries for agent actions. Pay-per-request via x402 (USDC on Base).","guidance":"POST to /mcp with a JSON-RPC body calling 'log_agent_action' with 'agentId', 'action', 'timestamp' (ISO 8601), and optional 'payload'/'outcome'. Include X-Payment-Tx header. Returns { receiptId, hmacSignature, timestamp, action, agentId, verified }."},"paths":{"/mcp":{"post":{"summary":"Create HMAC-signed audit log entry","description":"MCP endpoint for log_agent_action tool. Requires x402 payment (0.001 USDC on Base).","x-payment-info":{"protocols":["x402"],"pricingMode":"fixed","price":"0.001"},"parameters":[{"name":"X-Payment-Tx","in":"header","required":true,"description":"Transaction hash from USDC transfer on Base","schema":{"type":"string"}}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"type":"object","required":["jsonrpc","method","params","id"],"properties":{"jsonrpc":{"type":"string","enum":["2.0"]},"method":{"type":"string","enum":["tools/call"]},"params":{"type":"object","required":["name","arguments"],"properties":{"name":{"type":"string","enum":["log_agent_action"]},"arguments":{"type":"object","required":["agentId","action","timestamp"],"properties":{"agentId":{"type":"string","description":"Unique identifier for the agent"},"action":{"type":"string","description":"Description of the action performed"},"timestamp":{"type":"string","description":"ISO 8601 timestamp"},"payload":{"type":"object","description":"Optional structured payload"},"outcome":{"type":"string","description":"Optional outcome"}}}}},"id":{"type":"number"}}}}}},"responses":{"200":{"description":"Signed audit receipt","content":{"application/json":{"schema":{"type":"object","properties":{"receiptId":{"type":"string"},"hmacSignature":{"type":"string"},"timestamp":{"type":"string"},"action":{"type":"string"},"agentId":{"type":"string"},"verified":{"type":"boolean"}}}}}},"402":{"description":"Payment Required"}}}}}}