Struct RateLimitInterceptor 

pub struct RateLimitInterceptor { /* private fields */ }

A fixed-window rate limiting ServerInterceptor.

Tracks request counts per caller key using a simple fixed-window counter. When the limit is exceeded, rejects the request with an A2A error.

Caller keys are derived in this order:

1. CallContext::caller_identity (set by auth interceptors)
2. Client IP from x-forwarded-for, only when RateLimitConfig::trusted_proxy_hops is non-zero
3. "anonymous" fallback (shared bucket)

Implementations

impl RateLimitInterceptor

pub fn new(config: RateLimitConfig) -> ServerResult<Self>

Creates a new rate limiter with the given configuration.

Errors

Returns ServerError::InvalidParams if requests_per_window, window_secs, or max_buckets is zero. A zero window would divide by zero on every request; a zero limit or bucket cap would reject all requests.

Trait Implementations

impl Debug for RateLimitInterceptor

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl ServerInterceptor for RateLimitInterceptor

fn before<'a>( &'a self, ctx: &'a CallContext, ) -> Pin<Box<dyn Future<Output = A2aResult<()>> + Send + 'a>>

Called before the request handler processes the method call.

fn after<'a>( &'a self, _ctx: &'a CallContext, ) -> Pin<Box<dyn Future<Output = A2aResult<()>> + Send + 'a>>

Called after the request handler has finished processing.

fn authenticates(&self) -> bool

Returns true if this interceptor authenticates requests — i.e. its before hook rejects callers that do not present valid credentials.