Agent Embassy on Celo

Agent Embassy is a live agent-payments service: agents pay per call, and every call returns a signed outcome receipt. This entry is its Celo deployment, built during the hackathon window.

The service sells verification checks any agent can use, at 0.001 USD per call in USA₮ or USDC, settled through Celo's hosted x402 facilitator (x402 v2: the buyer signs an EIP-3009 authorization, the facilitator settles on Celo mainnet and pays the gas, funds move buyer to merchant directly):

— POST /v1/check/verify — send a URL; receive an attestation of what was observed (reachability, HTTP status, byte count, SHA-256 of the body). — POST /v1/check/ping — send a URL and your own conditions (HTTP status, body substring, JSON value); receive a signed pass/fail attestation naming each condition and its outcome. — POST /v1/check/changes — send a URL and a SHA-256 you already hold; receive a signed attestation of whether the body has changed since that hash.

Every settled call returns a signed receipt (embassy-receipt/2) carrying the payer, the amount, and the settlement transaction hash, hash-chained into an append-only log. Nothing in this entry asks to be trusted: the receipt signer is published at /.well-known/embassy-signer.json; GET /v1/receipts//verify re-derives the signature verdict and the chain-link verdict separately; the page at /proof renders the same checks for a human; and the settlement itself is read on Celoscan, independent of our server. The service also publishes its own discovery shelf (/.well-known/x402.json, /openapi.json, /llms.txt, /.well-known/agent.json), generated from the same route table the server answers from, so any agent can find the surface and price it without asking us.

Why USA₮: it is a US-dollar stablecoin issued by Anchorage Digital Bank, N.A. and supported by Tether, built to move between independent parties on cheap rails. The user it serves is any agent — or person — who needs a verifiable answer for a tenth of a cent, with no account, no card, and no subscription.

Identity: ERC-8004 agentId 9966 on Celo mainnet (registry 0x8004A169FB4a3325136EB29fA0ceB6D2e539a432), owned by the PayTo wallet below; its tokenURI is our agent card at https://aemb.pro/agent.json. Verify with ownerOf(9966) and tokenURI(9966) on any Celo RPC.

Attribution: per this hackathon's x402 rule, attribution rides the PayTo address (attribution tags are not yet supported by x402). PayTo: 0xD004278bC57FE4B9F743ABf17d713ed4169A88E9.

An honest note on usage: settlements from our own wallets prove the rail works; they are not independent usage and we do not present them as such. What we are putting in front of you is a real, public, mainnet surface that any outside agent can call from the moment it ships — and a receipt format that makes every call, from anyone, independently checkable.