Webhook Implementation

Best Practices

Respond immediately:

1. Validate signature
2. Return 200/202 within 1 second
3. Queue for async processing
4. Process in background

Idempotency:

• Store webhook id before processing
• Check if already processed
• Return 200 for duplicates

Out-of-order handling:

• Use state machine
• Only allow forward progress
• Use timestamps for resolution

Fulfillment Logic

Fulfill on payment.succeeded only.

Don't fulfill on:

• Return URL callbacks (manipulatable)
• Other webhook events

Retry Mechanism

Automatic retries on failure:

View failed webhooks at portal-test.sweuze.com.

Testing

Local development:

ngrok http 8000

Test scenarios:

• Successful payment
• Canceled payment
• Signature validation
• Idempotency
• Retry mechanism