# ZentPay Developer Docs

> ZentPay lets games, mini apps, AI tools, and web apps charge from 1 zent with a no-gas USDC Permit flow.

Use this index when integrating ZentPay. The full agent-readable integration guide is:

- https://docs.zentpay.app/zentpay.md
- https://docs.zentpay.app/developer-integration.md
- https://docs.zentpay.app/docs/developer/integration.md

## Essential URLs

- Portal: https://portal.zentpay.app
- Dev Console: https://dev.zentpay.app
- Docs root: https://docs.zentpay.app/
- Full Markdown guide: https://docs.zentpay.app/zentpay.md
- OpenAPI: https://docs.zentpay.app/openapi.json
- Webhook schema: https://docs.zentpay.app/webhook-event.schema.json
- Runtime manifest schema: https://docs.zentpay.app/runtime-manifest.schema.json
- Payment API: https://api.zentpay.app
- SDK: @zentpay/x402-pay@^0.2.4

## Integration Invariants

- Users sign only USDC EIP-2612 Permit typed data.
- ZentPay relays permit and charge calls so users do not need ETH.
- Product routes require short-lived authorizationCode, not raw authorizationId.
- payment.delivered is the trusted fulfillment event.
- payment.settled is the later chain settlement event.
- Fulfillment must depend on signed webhook or trusted server lookup, never frontend success alone.
- Keep API keys and webhook signing secrets on the backend only.

## Recommended Agent Reading Order

1. Read https://docs.zentpay.app/zentpay.md.
2. Read https://docs.zentpay.app/openapi.json for API paths and request/response shapes.
3. Read https://docs.zentpay.app/webhook-event.schema.json for signed webhook payloads.
4. Read https://docs.zentpay.app/runtime-manifest.schema.json if implementing Worker Quick Launch.