You only pay for what works.
Chowkidaar sits between autonomous AI agents and paid APIs. If a service times out, crashes, or returns the wrong shape, the agent is refunded on-chain from the merchant's bonded USDC. No tickets, no humans in the loop.
https://api.chowkidar.sahils.space/v1/call/<merchant>→ 402 → pay → 200Pay, check, settle or refund. Every step lands on Hedera; the receipt lands on HCS.
The demo agent holds its own Hedera key and pays the gateway over x402 with @x402/fetch. The gateway never sees the key.
Pays the merchant upfront over x402, runs the timer and the merchant's own JSON schema, then settles or refunds.
A real x402 seller on Hedera testnet. It posted a USDC bond into the vault before it could go live.
Valid JSON within the merchant's timeout. The merchant keeps the 0.1 USDC it was paid upfront, Chowkidaar keeps the 0.002 USDC fee, and the merchant's Arkiv reputation ticks up.
The agent is refunded 0.1 USDC from the vault in one atomic Hedera transfer, and the merchant's bond is slashed 0.12 USDC (price + 20% penalty). The failure is written to Arkiv.