# Integrate Penny Engine M2M

Start with a free, fixed-data demonstration: GET https://penny-paid-batch-production.up.railway.app/demo/proof-gate

Discover eight paid APIs without payment: GET https://penny-agent-api-production.up.railway.app/agent-services.json

Choose a service by task: GET https://penny-agent-api-production.up.railway.app/discover-paid?task=validate%20JSON%20result

Live outcome checker: POST https://penny-paid-batch-production.up.railway.app/api/proof-gate
Content-Type: application/json

Example JSON request: {"result":{"status":"completed","count":3},"expectations":{"requiredPaths":["status"],"equals":{"status":"completed"},"numberRanges":{"count":{"min":1,"max":10}}}}

A regular unauthenticated request to this paid route returns HTTP 402, not the result. An authorized x402-compatible payment client must interpret PAYMENT-REQUIRED, authorize the charge within its spending policy, and retry. We do not accept passwords or wallet private keys. SHA-256 result fingerprints are NOT signed execution attestations or verified payment receipts.

Current price $0.001 Base USDC per paid call. Independently verified outside settlements remain zero.