Client Architecture

rust-mcp-sdk provides two levels of client handler abstraction, mirroring the server side.

Handler Traits

Trait	Use Case
ClientHandler	Recommended - override only needed methods
ClientHandlerCore	Advanced - three raw methods for full message control

McpClient Trait

The McpClient trait provides methods to communicate with a connected server:

• request_tool_list() - list available tools
• request_tool_list() - list available tools
• request_tool_call() - invoke a tool
• request_resource_list() - list resources
• request_resource_read() - read a resource
• request_prompt_list() - list prompts
• request_prompt() - get a prompt
• request_completion() - get completions
• server_version() - get server identity info
• shut_down() - gracefully disconnect

Client Runtimes

Transport	Function
Stdio	client_runtime::create_client(McpClientOptions { .. }) or client_runtime_core::create_client(McpClientOptions { .. })
Streamable HTTP	client_runtime::with_transport_options(client_details, StreamableTransportOptions { mcp_url, .. }, handler, None, None, None)
SSE	client_runtime::with_transport_options(client_details, StreamableTransportOptions { mcp_url, .. }, handler, None, None, None)