M-Pesa Android App Integration

My Android app is still in development and I now need M-Pesa added as the primary payment option. The core screens and backend endpoints are already taking shape; what remains is a fully working, secure M-Pesa checkout flow built with Safaricom’s Daraja API.

You will:
• Wire the app to initiate STK Push, handle callbacks, and display clear success / failure states.
• Implement proper token generation, timestamp signing, and error handling so transactions comply with Safaricom guidelines.
• Provide concise setup notes that let my team rebuild the feature in Android Studio (Java or Kotlin) and test it on a sandbox before we go live.

I will grant access to the current Git repository, test credentials, and any additional endpoints you may need. Once your integration passes sandbox tests we can switch to production keys for a final round of verification.

If you have recent experience rolling out Daraja-based payments in Android apps, I’d love to see a quick example or two.