Server Architecture

rust-mcp-sdk provides two levels of server handler abstraction.

Handler Traits

Trait	Use Case
ServerHandler	Recommended - override only the methods you need
ServerHandlerCore	Advanced - three raw methods for full control

McpServer Trait

The McpServer trait is injected into every handler method via Arc<dyn McpServer>, providing:

• server_info() - server identity and capabilities
• client_info() - connected client details
• session_id() - session identifier (HTTP backends)
• auth_info() - current authentication data
• task_store() / client_task_store() - MCP Tasks support
• request_message_creation() - LLM sampling requests
• request_elicitation() - user input elicitation
• notify_*() methods - send notifications to the client

Server Runtimes

Transport	Function
Stdio	server_runtime::create_server() or server_runtime_core::create_server()
Streamable HTTP (Axum)	create_axum_server()
Streamable HTTP (Actix)	create_actix_server()