Struct Client 

pub struct Client { /* private fields */ }

The MCP client struct, managing transport, requests, and responses. This client is suitable for connecting to an MCP-compliant server to send requests, receive responses, and handle notifications.

Implementations

impl Client

pub fn new(transport: Arc<dyn Transport>) -> Self

Creates a new MCP client with the given transport. This does not perform initialization. You typically call client.initialize(...) next.

pub async fn initialize( &self, implementation: Implementation, capabilities: ClientCapabilities, ) -> Result<InitializeResult, Error>

Initializes the client by sending an “initialize” request containing:

• client implementation info
• client capabilities
• protocol version

On success, updates the client’s server_capabilities field and sends an initialized notification to the server.

pub async fn request( &self, method: &str, params: Option<Value>, ) -> Result<Value, Error>

Sends a request to the server with the given method and optional parameters, then waits up to 30 seconds for a matching response.

Errors

Returns an error if the transport fails, the server returns an error, or no response is received within 30 seconds.

pub async fn notify( &self, method: &str, params: Option<Value>, ) -> Result<(), Error>

Sends a notification to the server using the given method and optional parameters. Notifications do not expect a response from the server.

pub async fn capabilities(&self) -> Option<ServerCapabilities>

Returns the cached server capabilities if the client has already initialized.

pub async fn shutdown(&self) -> Result<(), Error>

Shuts down the client by closing the transport. This does not send a server shutdown request.

pub async fn list_tools(&self) -> Result<ListToolsResult, Error>

Lists available tools on the server by calling tools/list.

pub async fn call_tool( &self, name: &str, arguments: Value, ) -> Result<CallToolResult, Error>

Calls a tool on the server by name, passing the specified arguments as JSON. If the returned CallToolResult has is_error set to true, this method converts it into an Error::Other.

pub async fn get_tool(&self, name: &str) -> Result<Option<Tool>, Error>

Retrieves a single tool from the server by name, returning Some(tool) if found, or None otherwise.

pub async fn read_resource( &self, uri: &str, ) -> Result<ReadResourceResult, Error>

Reads a resource by URI from the server, calling resources/read.

pub async fn list_resources(&self) -> Result<ListResourcesResult, Error>

Lists resources by calling resources/list on the server.