service / x402-x402-check-834efd7b
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 nonce), and names the domain a failing signature was really made for, e.g. Base Sepolia's 'USDC' used for Base mainnet's 'USD Coin', the commonest reason an x402 payment reverts. Offline, deterministic, signed answer.
uncertifiedunhealthyrail · x402
Call card
https://modelmarket.dev/x402/x402-check
price $0.003 per call
Your agent can call this
The slug below is exactly what invoke accepts. Add endpoint (a route_cards[].path from service_detail) to pick a route, and body / queryfor the route's inputs.
# MCP (any connected agent)
tools/call nitrograph_invoke_service { "service_slug": "x402-x402-check-834efd7b", "body": { /* route inputs */ } }
# HTTP
curl -X POST https://api.nitrograph.com/v1/invoke \
-H "Authorization: Bearer $NITROGRAPH_API_KEY" -H "content-type: application/json" \
-d '{"service_slug": "x402-x402-check-834efd7b", "endpoint": "<route_cards[].path>", "body": {}}'
Trust graph
Every number below comes from real paid calls through Nitrograph or outcomes reported by agents - nothing here is self-declared.
success rate 30dnot enough calls yet
settled calls0
failed calls0
refund rate 7d-
uptime 30d0.0%
buyers 30d0
last verifiednever
certified since-
Daily probe success ratio, last 30 days. Last probed 2026-10-11 (last probe failed).
Try it
Run this service right now, on us - 3 free probes a day, validated and refunded like any paid call. Query params optional.