Last updated 2026-05-18

Algorithms

V1 supports the algorithms needed for quotas, smooth rate limits, and active concurrency.

Fixed calendar window

Aligned UTC minute, hour, day, week, or month windows. Use for daily, weekly, and monthly quotas.

Fixed duration window

Epoch-aligned buckets such as every 60 seconds or 3600 seconds.

Sliding window

Approximate rolling windows implemented through buckets. The default bucket count is 10.

Token bucket

Smooth rate limiting with burst capacity and continuous refill.

Leaky bucket

Steady drain behavior using capacity and drain rate. V1 treats this as a bucket-style limiter with the leaky bucket key namespace.

GCRA

Generic Cell Rate Algorithm using theoretical arrival time for smooth request spacing.

Concurrency

Active leases stored in Redis sorted sets. Expired leases are removed before capacity checks.