service / x402-file-f6b4b5ac
x402 Settlement Review
x402 Settlement Review: Replay and Double Charge — Reviews pasted seller-side x402 code that accepts the PAYMENT-SIGNATURE header, talks to the facilitator and delivers the goods (the cash register), for the silent failures that double-charge a buyer, hand the goods to a stranger or bill the seller. It flags an expiry check that runs before the nonce lookup, a repeat path that delivers without proof the chain observer lacks, a repeat window taken from the buyer's validBefore instead of the sell…
uncertifiedrail · x402
Call card
https://api.aiskills402.com/v1/skills/x402-settlement-review/file
price $0.01 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-file-f6b4b5ac", "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-file-f6b4b5ac", "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 30d100.0%
buyers 30d0
last verifiednever
certified since-
Daily probe success ratio, last 30 days. Last probed 2026-11-06.
Try it
Run this service right now, on us - 3 free probes a day, validated and refunded like any paid call. Query params optional.