service / x402-factorial-cd2fca42

Factorial (n≤20). Call for combinatorics demos and small counting problems with an explicit n cap. Returns n! for n up to 20; larger n returns a structured error. $0.001 USDC per successful call via x

Factorial (n≤20). Call for combinatorics demos and small counting problems with an explicit n cap. Returns n! for n up to 20; larger n returns a structured error. $0.001 USDC per successful call via x402 on Base—deterministic first-party JSON, no API key, no subscription, and nothing is billed on structured validation errors.

uncertifiedrail · x402

Call card

https://api.delx.ai/api/v1/x402/factorial price $0.001 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-factorial-cd2fca42", "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-factorial-cd2fca42", "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.