Reference5 min read•Audience: Developers
Error Codes & Troubleshooting Reference
Comprehensive catalog of error codes returned by the PostBrix API and engine, with exact root causes and remedies.
Key Takeaways
- Standardized JSON error envelope: { success: false, error: "CODE", message: "...", details?: [...] }.
- HTTP status codes: 400 Validation, 401 Unauthorized, 404 Not Found, 413 Payload Too Large, 429 Rate Limit, 500 Engine Error.
Standard Error Codes#
Handling Rate Limits & Exponential Backoff#
When receiving an HTTP 429 response:
- Inspect the
Retry-Afterheader, which indicates the number of seconds to pause before retrying. - Implement randomized exponential backoff with jitter on your client:
delay = min(maxDelay, baseDelay * 2 ** attempt) + randomJitter.
Frequently Asked Questions
What should I do if I get an MJML_COMPILE 500 error?
Inspect the response payload's details field. It will specify the exact line and MJML tag that caused the compilation parser to fail.
Can I request a rate limit increase for my workspace?
Yes. Contact PostBrix support or upgrade to an Enterprise tier to increase your requests/minute quota.