Agent Receipts — Verifiable Provenance for Autonomous-Agent Actions

# agent-receipts > Verifiable provenance for autonomous-agent actions — issue a signed, content-hashed, hash-chained receipt for any agent action; verify it later for audit, compliance, and dispute resolution. Built for autonomous AI agents. > Pay-per-call over the Model Context Protocol using the x402 "Payment Required" > standard (Coinbase x402, USDC on base). No signup, no API key to read the > free tiers; pay only for the premium result. ## MCP endpoint - https://agent-receipts.dropwatchhq.com/mcp (transport: streamable-http; call tools/list then tools/call) ## Paid tools (x402 pay-per-call, USDC on base) - `issue_receipt` — $0.01 USDC/call. Mint a signed (ed25519), content-hashed (SHA-256), timestamped, hash-chained provenance receipt for one agent action. ## Free tools - `verify_receipt` — free. Verify a receipt's authenticity + return its provenance record. - `list_receipts` — free. List an agent's receipt hash-chain, newest first. ## How an agent pays (x402 over MCP) 1. POST https://agent-receipts.dropwatchhq.com/mcp with JSON-RPC tools/call for a paid tool. The result returns a FREE PREVIEW plus an `x402` descriptor inside structuredContent: { "x402Version":1, "accepts":[ { "scheme":"exact", "network":"base", "maxAmountRequired":"<atomic USDC>", "asset":"<USDC on Base>", "payTo":"0x38134a7F97636E26365Fb17405566595B917a341", "extra":{"name":"USD Coin","version":"2"} } ] } 2. Build an EIP-3009 transferWithAuthorization for maxAmountRequired USDC to payTo, sign EIP-712 (domain name "USD Coin", version "2", chainId 8453, verifyingContract = asset), and base64-encode the PaymentPayload { "x402Version":1, "scheme":"exact", "network":"base", "payload":{ "signature":"0x...", "authorization":{ from,to,value,validAfter,validBefore,nonce } } } 3. Retry the SAME tools/call with header X-PAYMENT: <base64 payload> -> the full result, plus an X-PAYMENT-RESPONSE header (settlement receipt). The x402 client SDKs (x402-fetch