API Reference

Environment name override. When omitted, falls back to process.env.NODE_ENV or "development".

Values "development" and "test" use in-memory cache and rate limiting.

When true (default), use in-memory cache/rate-limit backends during static build phases (phase-production-build, phase-export via NEXT_PHASE).

Optional lifecycle hooks for observability and side effects.

Hooks are awaited; hook errors are logged and swallowed so they never affect rate limiting or fail-open behavior.

Application logger. Defaults to a silent no-op logger.

When true, skip rate limiting for every request from this client. Evaluated at client creation — no request is available. Use per-call skipRateLimit for request-aware skip logic.

Override built-in tier limits/windows/prefixes. Each tier key is optional; each field inside a tier is optional and merged onto factory defaults.

Legacy Upstash credentials or client.

Mutually exclusive with store. Use store: upstashStore({ url, token }) for new projects.

Explicit store implementation (preferred).

Checks the rate limit for an Express request without wrapping a handler.

Returns a cached rate limiter adapter for a tier.

Express middleware that rate-limits before next().

Sends 429 with standard headers when blocked; calls next() when allowed.

Clears in-memory limiter state and the adapter cache.

Useful in tests; does not reset Upstash Redis counters.

Express middleware with per-user rate limiting.

Uses getUserId(req) as the identifier; falls back to IP when null.

Wraps an Express route handler with rate limiting.

Sends 429 when blocked; invokes the handler when allowed.

Wraps an Express route handler with per-user rate limiting.

Function to get the identifier for the request. Defaults to the IP address of the request.

Redis key prefix override for this call. Defaults to the tier prefix.

Skip rate limit for this request.

Rate limit tier to use. Defaults to "moderate".