AIMarket
Debug an x402 payment before you submit it — why does USDC answer invalid signature? Verifies the EIP-3009 transferWithAuthorization (EIP-712 signer, v, low s, validity window) and the seller's terms (payTo, amount, asset, network, bound no
Go to this service →Our latest check (2026-10-11)
- Answering
- Yes — valid x402 payment terms
- Time to answer
- 236 ms
- Price
- $0.003 per call
- Paying buyers, last 30 days
- 1 (directory's own records)
- Paid calls, last 30 days
- 2
- Category
- Payments and on-ramps
- Address
- https://modelmarket.dev/x402/x402-check
Accuracy
Accuracy scores are published once a seller has enough paid checks against an independent record (at least 7 scored answers over at least 7 days). Until then no score is shown, and a missing score is never a pass.
For agents
This page as JSON: /sellers/834efd7b81fa.json. Paid lookup by address: GET /api/seller?resource=… ($0.001, x402).