Rate Limiting

Layer uses a single API-wide endpoint cost rate limiting system, where every endpoint contributes a cost towards a total budget. The budget follows a bucket model, where each API call uses tokens from a current bucket which is refilled every 1 second.

Default Rate Limits

Most endpoints use the following default rate limits:

Environment	Limit	Refill Period	Initial Size
Sandbox	100 requests	1 second	100 requests
Production	500 requests	1 second	100 requests

Some endpoints have custom rate limit policies with different limits. These are documented on the individual endpoint pages.

Rate Limit Headers

Rate limits should never be approached for normal customer read operations, and are only intended to limit heavy data ingestion processes, such as en-masse backfills of data. Nonetheless, we recommend adding retries on all Layer API calls. To assist in retries, the following headers are included in every successful API request:

• X-RateLimit-Limit: a specified bucket capacity.
• X-RateLimit-Remaining: the number of tokens remaining in a bucket.
• X-RateLimit-Reset: a UTC timestamp (in seconds) that specifies the time of refilling a bucket.

Any API calls that are rate limited will receive a response with:

• Error code 429: Too Many Requests
• Retry-After header indicating (in seconds) how long to wait before retrying the request.

During normal operations, adding enough retries that requests will retry 1 second later should be sufficient to avoid any rate limiting.