ratelimit/memory

Fixed-window rate limiting per client ip, held in memory (one process). Buckets come from config: buckets: { login: { limit: 5, windowSeconds: 60 } }. Step ratelimit.check:<bucket> fails RATE_LIMITED (429, Retry-After from details.retryAfterSeconds) once the limit is reached; the bucket name is validated at boot. ratelimit.sweep (cron) drops expired windows. Behind a proxy set http.trustProxy/proxyHops or trustedHeader so the real client ip is used. A request without a derivable address (ctx.ip absent – no trusted header, a forwarding chain shorter than proxyHops) is counted in one shared key "unknown" per bucket, so such requests are limited together rather than skipped; refusing them outright is the job of http.allow or the host's middleware. Not included: shared limits across processes (needs a store-backed module), per-user keys.

Generated from the manifest

@michaelthielemann/kestrel-ratelimit-memory – module ratelimit/memory: provides no contract.

| Config | Type | Required | Default | |---|---|---|---| | buckets | record | yes | – |

| Step | Summary | Reads | Writes | Input | Output | Errors | |---|---|---|---|---|---|---| | ratelimit.check:<arg> | Rate limit bucket | – | – | – | – | 429 too many requests | | ratelimit.sweep | Drop expired rate-limit windows | – | result | – | { removed?: number, … } | – |

Pipelines in examples/minimal using these steps:

• login (POST /login): ratelimit.check:login → authn.login → events.emit:auth.loggedIn
• sweepRateLimits (cron */5 * * * *): ratelimit.sweep