go-ratelimit

Provider-agnostic sliding window rate limiter for LLM API calls. Enforces requests per minute (RPM), tokens per minute (TPM), and requests per day (RPD) quotas per model using an in-memory sliding window. Ships with default quota profiles for Gemini, OpenAI, Anthropic, and a local inference provider. State persists across process restarts via YAML (single-process) or SQLite (multi-process, WAL mode). Includes a Gemini-specific token counting helper and a YAML-to-SQLite migration path.

Module: forge.lthn.ai/core/go-ratelimit Licence: EUPL-1.2 Language: Go 1.25

Quick Start

import "forge.lthn.ai/core/go-ratelimit"

// YAML backend (default, single-process)
rl, err := ratelimit.New()

// SQLite backend (multi-process)
rl, err := ratelimit.NewWithSQLite("~/.core/ratelimits.db")
defer rl.Close()

ok, reason := rl.CanSend("gemini-2.0-flash", 1500)
if ok {
    rl.RecordUsage("gemini-2.0-flash", 1500)
}

Documentation

• Architecture — sliding window algorithm, provider quotas, YAML and SQLite backends
• Development Guide — prerequisites, test patterns, coding standards
• Project History — completed phases with commit hashes, known limitations

Build & Test

go test ./...
go test -race ./...
go vet ./...
go build ./...

Licence

European Union Public Licence 1.2 — see LICENCE for details.