FAQ & Troubleshooting

Common issues

• I received a 401 Unauthorized — Verify your API key and ensure it's included as Authorization: Bearer YOUR_API_KEY.
• I received a 429 Too Many Requests — You've hit a rate limit. Implement exponential backoff and reduce parallel requests.
• Messages are marked as failed — Check the error reason in the message status. Verify the phone number format is correct (international format, e.g. +244923000000).

Debugging tips

• Use the message status endpoints to inspect delivery events.
• Check webhook logs in the dashboard to see inbound notifications.

Support

If you need help, open a support ticket from the dashboard or email support@castbrick.com. Include message IDs and timestamps for faster troubleshooting.