HTTP Status Code 429 - Too Many Requests

1. APIs return a HTTP response code - 429 (too many requests) when requests are rejected due to rate limiting
2. We may choose to enqueue rate-limited requests to be processed later

Headers in a 429 response

• X-Ratelimit-Remaining: The remaining number of allowed requests within the window.
• X-Ratelimit-Limit: It indicates how many calls the client can make per time window.
• X-Ratelimit-Retry-After: The number of seconds to wait until you can make a request again without being throttled.

Related Notes

• Message queues

Sources

• (Done) Design A Rate Limiter - Highlights