service / x402-firewall-0843e597

Buyer Side Payment Firewall API

Buyer-side payment firewall: should THIS agent make THIS payment now? Where /api/assess vets the seller, this vets the payment against your own agent's behaviour. POST {agent_id, payment:{payto_address,amount,resource_url}, context?:{untrusted_text,intended,expected_payto}, policy?} returns allow/hold/block plus 9 signals incl. routing_anomaly, velocity, amount_anomaly, injection_destination and intent_mismatch. Stateful per agent_id.

uncertifiedrail · x402

Call card

https://402sentinel.com/api/firewall price $0.002 per call

Your agent can call this

The slug below is exactly what invoke accepts. Addendpoint (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-firewall-0843e597", "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-firewall-0843e597", "endpoint": "<route_cards[].path>", "body": {}}'

Reliability

uptime 30d-

refund rate 7d-

settled calls0

failed calls0

certified since-

Daily probe success ratio, last 30 days. Last probed 2026-08-26.

Try it

Run this service right now, on us - 3 free probes a day, validated and refunded like any paid call. Query params optional.