How do I handle API rate limits without losing requests?

Reading rate limit headers

APIs communicate limits via response headers: remaining calls, reset time, or requests per minute. Read these headers after each call to know your current quota. When you hit the limit, requests fail with a 429 status code.

Queue-based approach

Instead of making requests directly, queue them. A background worker processes the queue at your allowed rate. If you're limited to 10 req/sec, the queue releases one every 100ms. This prevents hammering the API and is more reliable than retry loops.

Retry with backoff

If you do hit a 429, wait before retrying. Start with a short wait (1-2 seconds), then increase exponentially (double each retry). Most APIs mention their recommended backoff in documentation.

Monitor before limits

Track your usage hourly. If you're at 80% of your limit with hours remaining, you're on pace to exceed it. Slow down proactively instead of reactively.