Struct RequestContext 

pub struct RequestContext {
    pub request_id: String,
    pub user_id: Option<String>,
    pub session_id: Option<String>,
    pub client_id: Option<String>,
    pub timestamp: Timestamp,
    pub start_time: Instant,
    pub metadata: Arc<HashMap<String, Value>>,
    pub cancellation_token: Option<Arc<CancellationToken>>,
    /* private fields */
}

Context information for a single MCP request, carried through its entire lifecycle.

This struct contains essential metadata for processing, logging, and tracing a request, including unique identifiers, authentication information, and mechanisms for cancellation and server-initiated communication.

Fields

request_id: String

A unique identifier for the request, typically a UUID.

user_id: Option<String>

The identifier for the user making the request, if authenticated.

session_id: Option<String>

The identifier for the session to which this request belongs.

client_id: Option<String>

The identifier for the client application making the request.

timestamp: Timestamp

The timestamp when the request was received.

start_time: Instant

The Instant when request processing started, used for performance tracking.

metadata: Arc<HashMap<String, Value>>

A collection of custom metadata for application-specific use cases.

cancellation_token: Option<Arc<CancellationToken>>

A token that can be used to signal cancellation of the request.

Implementations

impl RequestContext

pub fn new() -> Self

Creates a new RequestContext with a generated UUIDv4 as the request ID.

pub fn with_id(id: impl Into<String>) -> Self

Creates a new RequestContext with a specific request ID.

pub fn with_user_id(self, user_id: impl Into<String>) -> Self

Sets the user ID for this context, returning the modified context.

Example

let ctx = RequestContext::new().with_user_id("user-123");
assert_eq!(ctx.user_id, Some("user-123".to_string()));

pub fn with_session_id(self, session_id: impl Into<String>) -> Self

Sets the session ID for this context, returning the modified context.

pub fn with_client_id(self, client_id: impl Into<String>) -> Self

Sets the client ID for this context, returning the modified context.

pub fn with_metadata( self, key: impl Into<String>, value: impl Into<Value>, ) -> Self

Adds a key-value pair to the metadata, returning the modified context.

Example

let ctx = RequestContext::new().with_metadata("tenant", json!("acme-corp"));
assert_eq!(ctx.get_metadata("tenant"), Some(&json!("acme-corp")));

pub fn get_metadata(&self, key: &str) -> Option<&Value>

Retrieves a value from the metadata by key.

pub fn elapsed(&self) -> Duration

Returns the elapsed time since the request processing started.

pub fn is_cancelled(&self) -> bool

Checks if the request has been marked for cancellation.

pub fn with_server_to_client( self, capabilities: Arc<dyn ServerToClientRequests>, ) -> Self

Sets the server-to-client requests interface for this context.

This enables tools to make server-initiated requests (sampling, elicitation, roots) with full context propagation for tracing and attribution. This is typically called by the server implementation.

pub fn with_cancellation_token(self, token: Arc<CancellationToken>) -> Self

Sets the cancellation token for cooperative cancellation. This is typically called by the server implementation.

pub fn user(&self) -> Option<&str>

Returns the user ID from the request context, if available.

pub fn is_authenticated(&self) -> bool

Checks if the request is from an authenticated client. This is determined by metadata set during the authentication process.

pub fn roles(&self) -> Vec<String>

Returns the user roles from the request context, if available. Roles are typically populated from an authentication token.

pub fn has_any_role<S: AsRef<str>>(&self, required: &[S]) -> bool

Checks if the user has any of the specified roles. Returns true if the required roles list is empty or if the user has at least one of the roles.

Trait Implementations

impl Clone for RequestContext

fn clone(&self) -> RequestContext

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RequestContext

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

Formats the value using the given formatter.

impl Default for RequestContext

fn default() -> Self

Returns the “default value” for a type.

impl RequestContextExt for RequestContext

fn with_enhanced_client_id(self, client_id: ClientId) -> Self

Sets the client ID using the structured ClientId enum, which includes the method of identification.

fn extract_client_id( self, extractor: &ClientIdExtractor, headers: Option<&HashMap<String, String>>, query_params: Option<&HashMap<String, String>>, ) -> Self

Extracts a client ID from headers or query parameters and sets it on the context.

fn get_enhanced_client_id(&self) -> Option<ClientId>

Gets the structured ClientId enum from the context, if available.