Skip to main content

ServerInterceptor

a2a_protocol_sdk::server

Trait ServerInterceptor 

Source 
pub trait ServerInterceptor:
    Send
    + Sync
    + 'static {
    // Required methods
    fn before<'a>(
        &'a self,
        ctx: &'a CallContext,
    ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + Send + 'a>>;
    fn after<'a>(
        &'a self,
        ctx: &'a CallContext,
    ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + Send + 'a>>;

    // Provided method
    fn authenticates(&self) -> bool { ... }
}
Expand description

A server-side interceptor for request processing.

Interceptors run before and after the core handler logic. They can be used for logging, authentication, rate-limiting, or other cross-cutting concerns.

§Object safety

This trait is designed to be used behind Arc<dyn ServerInterceptor>.

Required Methods§

Source

fn before<'a>( &'a self, ctx: &'a CallContext, ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + Send + 'a>>

Called before the request handler processes the method call.

Return Err(...) to abort the request with an error response.

§Errors

Returns an A2aError to reject the request.

Source

fn after<'a>( &'a self, ctx: &'a CallContext, ) -> Pin<Box<dyn Future<Output = Result<(), A2aError>> + Send + 'a>>

Called after the request handler has finished processing.

This is called even if the handler returned an error. It should not alter the response — use it for logging, metrics, or cleanup.

§Errors

Returns an A2aError if post-processing fails.

Provided Methods§

Source

fn authenticates(&self) -> bool

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

The extended agent card endpoint MUST require authentication (spec §13.3); the handler uses this marker to verify that at least one authenticating interceptor guards the chain before serving the card. The default is false (logging/metrics-style interceptors do not authenticate); auth interceptors — including custom ones — should override this to true.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§