nandinideshmukh/rate-limiter

How nandinideshmukh/rate-limiter works

RateLimitX is an HTTP rate-limiting service. Requests to /api/ are identified by API key or client IP, assigned a policy, checked by its configured Redis-backed algorithm, and either rejected with rate-limit headers or passed to the API handler. The service also serves an embedded page, health endpoints, and Prometheus metrics. The source excerpts show all five Redis-backed algorithms and some Lua scripts; other script and deployment wiring is not inspected, so those relationships are omitted.

Main entry points: main.go HTTP server · ratelimit.go Rate-limit middleware · fixed_window.go Redis fixed window · sliding_window_counter.go Redis sliding counter

Components 21

HTTP service

HTTP server cmd/server/main.go
API handler cmd/server/main.go
Embedded page web/assets.go

Policy and enforcement

Policy manager internal/policy/manager.go
Rate-limit middleware internal/middleware/ratelimit.go

Limiter algorithms

Fixed window logic internal/limiter/fixed_window.go
Sliding counter logic internal/limiter/sliding_window_counter.go
Sliding log logic internal/limiter/sliding_window_log.go
Token bucket logic internal/limiter/token_bucket.go
Leaky bucket logic internal/limiter/leaky_bucket.go
Redis fixed window internal/storage/fixed_window.go
Redis sliding counter internal/storage/sliding_window_counter.go
Redis sliding log internal/storage/sliding_window_log.go
Redis token bucket internal/storage/token_bucket.go
Redis leaky bucket internal/storage/leaky_bucket.go

Metrics and health

Request metrics internal/metrics/metrics.go
Prometheus endpoint

Other components

HTTP client
Redis
Prometheus service
Grafana service

Connections 24

HTTP client → HTTP server: sends requests cmd/server/main.go
HTTP server → Rate-limit middleware: routes /api cmd/server/main.go
HTTP server → Embedded page: serves page cmd/server/main.go
HTTP server → Prometheus endpoint: serves metrics cmd/server/main.go
HTTP server → Prometheus service: checks health cmd/server/main.go
HTTP server → Grafana service: checks health cmd/server/main.go
HTTP server → Policy manager: configures policies cmd/server/main.go
HTTP server → Redis fixed window: constructs backend cmd/server/main.go
HTTP server → Redis sliding counter: constructs backend cmd/server/main.go
HTTP server → Redis sliding log: constructs backend cmd/server/main.go
HTTP server → Redis token bucket: constructs backend cmd/server/main.go
HTTP server → Redis leaky bucket: constructs backend cmd/server/main.go
Rate-limit middleware → Policy manager: selects policy internal/middleware/ratelimit.go
Rate-limit middleware → Redis fixed window: checks limit internal/middleware/ratelimit.go
Rate-limit middleware → Redis sliding counter: checks limit internal/middleware/ratelimit.go
Rate-limit middleware → Redis sliding log: checks limit internal/middleware/ratelimit.go
Rate-limit middleware → Redis token bucket: checks limit internal/middleware/ratelimit.go
Rate-limit middleware → Redis leaky bucket: checks limit internal/middleware/ratelimit.go
Rate-limit middleware → API handler: allows request internal/middleware/ratelimit.go
Rate-limit middleware → Request metrics: records outcomes internal/middleware/ratelimit.go
Prometheus endpoint → Request metrics: exposes metrics
Redis fixed window → Redis: runs script internal/storage/fixed_window.go
Redis sliding counter → Redis: runs script internal/storage/sliding_window_counter.go
Redis leaky bucket → Redis: runs script internal/storage/leaky_bucket.go

Drawn by GitDiagram on November 10, 2026 from the repository's file tree, README and source files. Read as Markdown ·