Pay one cent in USDC on Arc and get gap133's live, verified cross-venue prediction-market gaps. No account, no subscription, no API key. Every answer is signed, so an agent can prove it came from gap133.
The service answers your first request with HTTP 402 Payment Required and a one-time nonce. You call pay(nonce) on the contract with the exact price in native USDC. The service reads the payment on Arc (finality is under a second) and returns the data with the attester's signature in the X-Signature header. The attester address is stored in the contract, so anyone can check it.
curl -i https://arc.gap133.xyz/api/query?kind=top
# -> 402 { nonce, challenge, contract, price }
# pay(nonce) on Arc, then:
curl https://arc.gap133.xyz/api/query?kind=top \
-H "X-Payment-Challenge: <challenge>" -H "X-Payment-Tx: <tx hash>"
Agents: see examples/agent.mjs for a script that pays and verifies on its own.