What to do if your application is receiving a 429 rate limit error message

If your application receives an HTTP 429 status code, it means you have exceeded your assigned API rate limit. Rate limits are in place to ensure platform stability and protect against both intentional and unintentional abuse.

A rate limit defines the maximum number of requests allowed within a specific time window. When this threshold is crossed, the platform temporarily blocks further requests.

How to Resolve Rate Limiting

The primary solution is to reduce the frequency of your API calls. While every architecture is different, consider the following strategies:

• Implement a Queuing System: Use a job/worker pattern to buffer requests (e.g., sending SMS) and process them at a steady rate that stays below your limit.

• Monitor Response Headers: Inspect the HTTP response headers provided by the API. These headers often contain real-time data on your remaining quota and when the limit will reset.

• Artificial Delays (Throttling): As a short-term fix, you can introduce "sleep" commands or delays in your code to slow down execution.

• Optimize Authentication: Ensure you aren't stuck in an authentication loop (see "Common Scenarios" below).

Common Scenarios: Authentication Loops

A frequent cause of 429 errors is aggressive retry logic during authentication. If a user’s credentials change or an account is deactivated, your app may enter a high-speed loop attempting to re-authenticate.

• The Culprit: This is common in apps using the (now-deprecated) Password Grant flow.

• How to Diagnose: Log in to the Developer Console, select your app, and go to the Analytics tab. View "API Calls by Endpoint." If you see a spike in errors on the /authorize or /token endpoints, your auth logic is likely the cause.

• The Fix: Transition to a more resilient JWT (JSON Web Token) authentication or improve your Refresh Token methodology.

Requesting a Limit Increase

If architectural changes cannot meet your business requirements, you may request a higher limit.

1. File a ticket with Developer Support.

2. Be prepared to provide:

   • A description of your application’s use case.

   • Current and projected API call volume.

   • Steps you have already taken to optimize your code.

Helpful Resources:

• Detailed Guide to Rate Limits

• Developer Support Portal