Platform APIs (backend)

The Platform API is the server-side API surface of the Pi ecosystem. You’ll use it to verify users, approve and complete payments, create server-initiated payments (A2U payments), and validate rewarded ads.

If you’re looking for frontend JavaScript SDK installation and window.Pi usage, start at the Pi SDK section.

What the Platform API is for

• Authentication verification: validate a user session from your backend via GET /me (using the user access token).
• Payments:
  • U2A (User-to-App): your frontend starts the flow, but your backend must approve and complete it.
  • A2U (App-to-User): your backend creates payments directly on behalf of your app (for example, payouts or rewards). See Advanced Payments for server-initiated and more complex flows.
  • Flow model: all payments move through Server-Side Approval (for U2A) and Server-Side Completion (for all payment types). For a visual walkthrough, see the Payments guide.
• Ads: verify rewarded ad status before granting rewards.

Authorization (important)

The Platform API supports:

• Access token auth: Authorization: Bearer <user access token> (user-scoped endpoints like /me)
• Server API key auth: Authorization: Key <server API key> (server-only endpoints like payment approval/completion)

Your Server API key must never be exposed in frontend code.

How the frontend SDK plugs into the Platform API

• Frontend calls Pi.authenticate(...) → you get an accessToken → backend calls GET /me to verify identity.
• Frontend calls Pi.createPayment(...) → callbacks provide paymentId / txid → backend calls:
  • POST /payments/{payment_id}/approve
  • POST /payments/{payment_id}/complete
• Frontend shows a rewarded ad → you get an adId → backend calls GET /ads_network/status/:adId before rewarding.

Start here

• Platform API reference: Platform API
• Authentication guide: Authentication
• Payments guide: Payments and Advanced Payments
• Ads guide: Ads
• Developer Portal / app setup: Developer Portal
• End-to-end example app: Pi Demo App – complete open-source reference showing how the frontend SDK and Platform API work together.

Advanced topics

• PiNet (subdomain + metadata): PiNet – create a *.pinet.com URL for your app and control Open Graph / Twitter Card metadata that Pi exposes for previews/sharing.
• Custom tokens on Pi Testnet: Tokens – create and manage testnet tokens, configure pi.toml, and integrate with Pi Wallet.