Glossary

Token bucket

Token bucket is a rate limiting algorithm where a virtual bucket accumulates tokens at a fixed refill rate up to a maximum capacity (the burst limit). Each request consumes one or more tokens. If the bucket has enough tokens the request proceeds immediately; if not, it is queued or rejected with a 429. The bucket capacity determines the maximum burst size above the steady-state rate.

Formula: refill_rate = steady-state requests/s; bucket_capacity = max burst; burst above refill allowed until the bucket empties.

Last updated: March 2026