Pi Authentication

Implement Pi Network authentication using the Pi SDK. Pi Apps must use Pi Authentication exclusively - no email/password or third-party auth allowed.

When to Use This Skill

•Implementing Pi login flow
•Verifying Pioneer identity on the backend
•Debugging authentication issues
•Handling access token expiry or validation errors

SDK Authentication (Frontend)

Initialize the SDK first:

html

<script src="https://sdk.minepi.com/pi-sdk.js"></script>
<script>Pi.init({ version: "2.0" })</script>

Call authenticate:

javascript

const Pi = window.Pi;
const scopes = ['username', 'payments'];

function onIncompletePaymentFound(payment) {
    // MUST handle incomplete payments from previous sessions
    axios.post('/api/payments/incomplete', { payment });
}

Pi.authenticate(scopes, onIncompletePaymentFound)
    .then(function(auth) {
        // auth.accessToken - dynamic string, changes periodically
        // auth.user.uid    - static, app-specific Pioneer identifier
        // auth.user.username - only returned with 'username' scope
    })
    .catch(function(error) {
        console.error(error);
    });

AuthResults Object

json

{
    "accessToken": "string (dynamic, rotates at intervals)",
    "user": {
        "uid": "string (static, app-specific identifier)",
        "username": "string (only with 'username' scope)"
    }
}

Available Scopes

Scope	Purpose	Extra Data
`username`	Get Pioneer's username	`user.username`
`payments`	Enable Pi payments	None

No specific scope is required to obtain the access token itself.

Server-Side Verification (Backend)

Verify Pioneer identity by calling the Pi Platform API /me endpoint:

javascript

// Node.js example
const headers = { authorization: "Bearer " + accessToken };
const response = await axios.get("https://api.minepi.com/v2/me", { headers });
// response.data => { uid: "string", username: "string" }

python

# Python example
import requests
headers = {"Authorization": f"Bearer {access_token}"}
response = requests.get("https://api.minepi.com/v2/me", headers=headers)
# response.json() => {"uid": "...", "username": "..."}

Returns 401 if token is invalid or tampered.

Auth Flow for This Project

code

Pi.authenticate() -> accessToken + uid
  -> POST /api/auth/verify (send accessToken to backend)
  -> Backend calls GET api.minepi.com/v2/me (verify token)
  -> Backend creates/updates user record using verified uid
  -> Return JWT for session management

Security Rules

•NEVER save accessToken or uid from frontend directly to database
•ALWAYS verify via server-side /me endpoint before trusting any identity
•A malicious actor can pass forged or corrupt access tokens from the frontend
•Only the uid returned from the /me API is trustworthy for DB records
•Access tokens are short-lived and dynamic - never cache them long-term
•Do not use localStorage as an auth fallback - must use Pi SDK only
•Disable dev-login / test-mode endpoints in production

Troubleshooting

Issue	Cause	Fix
401 from `/me`	Expired or forged token	Re-authenticate via SDK
`Pi is undefined`	SDK not loaded	Ensure script tag before `Pi.init()`
Sandbox auth fails	Dev URL not registered	Register in Developer Portal
Missing username	Scope not requested	Add `'username'` to scopes array