jhurliman/node-rate-limiter
Node Rate Limiter
Node-rate-limiter is a utility library for Node.js designed to throttle both incoming and outgoing traffic using configurable time intervals and token bucket limits. It protects server capacity and backend APIs by capping the number of requests an individual client can make within a specified time window, while also controlling the frequency of outbound API calls and web crawling tasks to avoid triggering remote rate limit violations.
The library implements a token-bucket rate limiting algorithm with continuous replenishment, allowing administrators to configure specific burst and drip rates. This enables short surges of traffic while maintaining a steady long-term throughput capacity. It calculates request permissions dynamically against sliding or fixed time intervals to enforce strict usage quotas.
State management is handled locally in memory for synchronous lookups during request validation. The engine also provides non-consuming inspection methods that allow callers to check remaining token counts and allowance thresholds without mutating the underlying rate limit state, supporting conditional execution decisions based on limits.
Features
- Token Bucket Throttlers - Implements a token bucket rate limiting algorithm with continuous replenishment to cap long-term throughput.
- Rate Limiters - Provides a Node.js utility for throttling incoming and outgoing traffic using time intervals and token buckets.
- Traffic Burst Management - Allows configuring specific burst and drip rates to permit short surges of traffic while maintaining steady throughput.
- Per-Client Request Throttlers - Caps how many requests an individual client can make within a specified time window to protect server capacity.
- Request Throttling - Controls the frequency of outbound API calls and web crawling tasks to prevent remote rate limit violations.
- Time-Windowed Limits - Calculates request permissions dynamically over sliding or fixed time windows to enforce strict usage quotas.
- Middleware Rate Limiters - Provides rate limiting middleware that protects server capacity by capping client requests within time windows.
- API Rate Limiting - Protects backend servers and Node.js APIs from overload by capping incoming request volume within time windows.
- In-Memory State Management - Maintains client token counts and timestamps in volatile memory for fast synchronous lookups during request validation.
- Outgoing Throttling - Controls outbound traffic frequency for API requests and web crawling tasks to avoid rate limit errors.
- State Inspections - Provides accessor methods to check remaining allowance thresholds without mutating the underlying rate limit state.
- Token Capacity Checks - Allows callers to inspect remaining token counts and thresholds without consuming tokens.
