Module rate_limit 

Identity-aware rate limiting middleware.

Requests are keyed by authenticated identity (API key ID or user ID) when available, falling back to the client IP address. Each key gets a fixed-window counter that resets every 60 seconds.

The client IP is the address of the TCP peer, so the server must be served with into_make_service_with_connect_info::<SocketAddr>(). The configured forwarding header (TrustedProxies::header) is read only when that peer is one of the TrustedProxies: any client can write it. Without a peer address the IP limit is skipped.

With AccountLimit::ByEmail, a request whose JSON body names an email is also counted against that account, so spreading attempts on one account over many IP addresses does not help.

Responses carry standard rate-limit headers:

• X-RateLimit-Limit – maximum requests allowed per window
• X-RateLimit-Remaining – requests left in the current window
• X-RateLimit-Reset – epoch timestamp when the window resets

A request is counted under an API key only once its secret is verified, and the key’s rate_limit_override replaces the server-wide default only when the key is owned by an admin. Secrets not yet verified are checked at most KEY_CHECKS_PER_MINUTE times per client and key each minute.

Structs

InvalidClientIpHeader

A ClientIpHeader name that is neither x-forwarded-for nor x-real-ip.

InvalidTrustedProxy

A TrustedProxies entry that is neither an IP address nor a CIDR range.

RateLimitContext

Context needed by the rate limit middleware.

RateLimitState

Shared rate limiter state with fixed-window counters.

TrustedProxies

Reverse proxies whose forwarding header is believed, and which header that is.

Enums

AccountLimit

Whether the limiter also counts requests against the account they target.

ClientIpHeader

The forwarding header a trusted proxy reports the client IP in.

RateLimitKey

Rate limit key: identity-based when authenticated, IP-based otherwise.

Functions

per_minute

Build a per-identity rate limiter allowing requests_per_minute requests per minute.

rate_limit

Axum middleware that enforces identity-aware rate limiting.