Crate tower_rate_tier 

Tier-based rate limiting middleware for tower services.

Assign users to named tiers (e.g. “free”, “pro”) with distinct quotas, and let the middleware enforce limits automatically via the GCRA algorithm.

Features

• buffered-body: identify users from the request body (TierLimitLayer::buffer_body).
• redis: RedisStorage keeps the limits in Redis, shared by every instance of a service. Requires Rust 1.88.

Re-exports

pub use cost::tier_cost;

pub use cost::TierCost;

pub use event::LimitEvent;

pub use gcra::RateLimitInfo;

pub use gcra::RateLimited;

pub use identifier::TierIdentifier;

pub use identifier::TierIdentity;

pub use layer::TierLimitLayer;

pub use on_missing::OnMissing;

pub use on_storage_error::OnStorageError;

pub use on_unknown_tier::OnUnknownTier;

pub use quota::Nanos;

pub use quota::Quota;

pub use storage::StorageError;

pub use storage::StorageKey;

pub use tier::CheckError;

pub use tier::RateTier;

pub use buffered::BufferedTierLimitLayer;

pub use buffered::BufferedTierLimitService;

pub use storage::redis::RedisStorage;

Modules

buffered

Buffered-body variants that allow identifier access to the request body.

clock

Clock abstractions for real and deterministic (test) time sources.

cost

Cost extraction: decide how many tokens each request consumes.

event

Events reported while rate limiting, for logging and metrics.

gc

Background garbage collection for expired rate-limit entries.

gcra

Generic Cell Rate Algorithm (GCRA) implementation.

identifier

User identity and tier extraction from incoming requests.

layer

Tower Layer implementation that wraps services with rate limiting.

on_missing

Policy for handling requests whose identity cannot be resolved.

on_storage_error

Policy for handling storage backend errors.

on_unknown_tier

Policy for handling tiers that are not configured.

quota

Quota definitions (rate, burst, period).

response

HTTP response helpers for rate-limit headers and 429 replies.

service

Tower Service implementation that enforces per-tier rate limits.

storage

Storage backends for persisting rate-limit state.

tier

Tier configuration and the RateTier builder.