Struct RouterRequest 

pub struct RouterRequest {
    pub id: RequestId,
    pub inner: McpRequest,
    pub extensions: Extensions,
}

Request type for the tower Service implementation.

Preserving extensions in middleware

When rewriting a request in middleware, use with_inner or clone_with_inner instead of constructing a new RouterRequest directly. Constructing with Extensions::new() will silently drop extensions set by earlier middleware layers (token claims, RBAC context, etc.).

// WRONG: drops extensions from earlier middleware
let rewritten = RouterRequest {
    id: req.id.clone(),
    inner: new_inner,
    extensions: Extensions::new(),
};

// RIGHT: preserves extensions
let rewritten = req.with_inner(new_inner);

Fields

id: RequestId

The JSON-RPC request ID.

inner: McpRequest

The parsed MCP request.

extensions: Extensions

Type-map for passing data (e.g., TokenClaims) through middleware.

Implementations

impl RouterRequest

pub fn new(id: RequestId, inner: McpRequest) -> Self

Create a new RouterRequest with empty extensions.

pub fn with_inner(self, inner: McpRequest) -> Self

Replace the inner MCP request, preserving the id and extensions.

This is the recommended way to rewrite requests in middleware, as it ensures extensions set by earlier middleware layers (e.g., token claims, RBAC context) are not lost.

pub fn with_id_and_inner(self, id: RequestId, inner: McpRequest) -> Self

Replace both the id and inner MCP request, preserving extensions.

Useful when middleware needs to assign a new request id (e.g., for fan-out or request duplication) while keeping the extensions from the original request.

pub fn clone_with_inner(&self, inner: McpRequest) -> Self

Create a copy of this request with a different inner request, cloning the id and extensions from the original.

Unlike with_inner, this borrows self, which is useful when the original request is still needed (e.g., for traffic mirroring where you send the request to two backends).

Trait Implementations

impl Clone for RouterRequest

fn clone(&self) -> RouterRequest

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RouterRequest

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

Formats the value using the given formatter.

impl<S> Service<RouterRequest> for AuditService<S>

where S: Service<RouterRequest, Response = RouterResponse> + Clone + Send + 'static, S::Error: Send, S::Future: Send,

type Response = RouterResponse

Responses given by the service.

type Error = <S as Service<RouterRequest>>::Error

Errors produced by the service.

type Future = Pin<Box<dyn Future<Output = Result<RouterResponse, <S as Service<RouterRequest>>::Error>> + Send>>

The future response value.

fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>>

Returns Poll::Ready(Ok(())) when the service is able to process requests.

fn call(&mut self, req: RouterRequest) -> Self::Future

Process the request and return the response asynchronously.

impl<S> Service<RouterRequest> for CatchError<S>

where S: Service<RouterRequest, Response = RouterResponse> + Clone + Send + 'static, S::Error: Display + Send, S::Future: Send,

type Response = RouterResponse

Responses given by the service.

type Error = Infallible

Errors produced by the service.

type Future = CatchErrorFuture<<S as Service<RouterRequest>>::Future>

The future response value.

fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>>

Returns Poll::Ready(Ok(())) when the service is able to process requests.

fn call(&mut self, req: RouterRequest) -> Self::Future

Process the request and return the response asynchronously.

impl<S> Service<RouterRequest> for InjectAnnotations<S>

where S: Service<RouterRequest, Response = RouterResponse>,

type Response = RouterResponse

Responses given by the service.

type Error = <S as Service<RouterRequest>>::Error

Errors produced by the service.

type Future = <S as Service<RouterRequest>>::Future

The future response value.

fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>>

Returns Poll::Ready(Ok(())) when the service is able to process requests.

fn call(&mut self, req: RouterRequest) -> Self::Future

Process the request and return the response asynchronously.

impl Service<RouterRequest> for McpRouter

type Response = RouterResponse

Responses given by the service.

type Error = Infallible

Errors produced by the service.

type Future = Pin<Box<dyn Future<Output = Result<<McpRouter as Service<RouterRequest>>::Response, <McpRouter as Service<RouterRequest>>::Error>> + Send>>

The future response value.

fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>>

Returns Poll::Ready(Ok(())) when the service is able to process requests.

fn call(&mut self, req: RouterRequest) -> Self::Future

Process the request and return the response asynchronously.

impl<S> Service<RouterRequest> for McpTracingService<S>

where S: Service<RouterRequest, Response = RouterResponse, Error = Infallible> + Clone + Send + 'static, S::Future: Send,

type Response = RouterResponse

Responses given by the service.

type Error = Infallible

Errors produced by the service.

type Future = Pin<Box<dyn Future<Output = Result<RouterResponse, Infallible>> + Send>>

The future response value.

fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>>

Returns Poll::Ready(Ok(())) when the service is able to process requests.

fn call(&mut self, req: RouterRequest) -> Self::Future

Process the request and return the response asynchronously.

impl<S> Service<RouterRequest> for ToolCallLoggingService<S>

where S: Service<RouterRequest, Response = RouterResponse> + Clone + Send + 'static, S::Error: Send, S::Future: Send,

type Response = RouterResponse

Responses given by the service.

type Error = <S as Service<RouterRequest>>::Error

Errors produced by the service.

type Future = Pin<Box<dyn Future<Output = Result<RouterResponse, <S as Service<RouterRequest>>::Error>> + Send>>

The future response value.

fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>>

Returns Poll::Ready(Ok(())) when the service is able to process requests.

fn call(&mut self, req: RouterRequest) -> Self::Future

Process the request and return the response asynchronously.