Algorithms

Token Bucket

• Tokens refill at refill_rate per second
• Each request consumes one token
• Allows bursts up to capacity
• Good for APIs that tolerate occasional spikes

Leaky Bucket

• Requests queue up; they "leak" at leak_rate per second
• New requests rejected when queue is full
• Smooth, constant output rate
• Good for steady throughput (background jobs, pipelines)

Choosing

Use case	Algorithm
API with burst allowance	Token Bucket
Smooth rate enforcement	Leaky Bucket
Third-party API compliance	Either

See API Reference — Limiters for constructor parameters and methods.