Crate mcp_probe_core

MCP Core Library

mcp-core provides the foundational types, traits, and implementations for the Model Context Protocol (MCP). This crate is the core building block for MCP clients and debugging tools.

Features

• Complete MCP Message Types: All JSON-RPC message structures defined by the MCP specification
• Transport Abstraction: Unified interface for stdio, HTTP+SSE, and HTTP streaming transports
• Type-Safe Configuration: Compile-time validated configuration for all transport types
• Comprehensive Error Handling: Structured error types for all failure modes
• Async-First Design: Built on tokio for high-performance async I/O
• High-Level Client: Ready-to-use MCP client with protocol handling

Quick Start

use mcp_probe_core::{
    client::{McpClient, ClientConfig},
    transport::TransportConfig,
    messages::Implementation,
};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Configure a stdio transport
    let config = TransportConfig::stdio("python", &["server.py"]);
     
    // Create and connect client
    let mut client = McpClient::with_defaults(config).await?;
     
    let client_info = Implementation {
        name: "mcp-probe".to_string(),
        version: "0.1.0".to_string(),
        metadata: std::collections::HashMap::new(),
    };
     
    let server_info = client.connect(client_info).await?;
    println!("Connected to: {}", server_info.implementation.name);
     
    Ok(())
}

Architecture

The library is organized into several key modules:

• error: Comprehensive error types for all MCP operations
• messages: Complete MCP message type definitions
• transport: Transport abstraction and implementations
• client: High-level MCP client interface

Transport Support

This crate supports all three MCP transport mechanisms:

• stdio: Local process communication (enabled by default)
• http-sse: HTTP + Server-Sent Events (enabled by default)
• http-stream: Full-duplex HTTP streaming (enabled by default)

Transport support can be controlled via feature flags.

Re-exports

pub use client::ClientConfig;

pub use client::ClientState;

pub use client::ClientStats;

pub use client::McpClient;

pub use client::ServerInfo;

pub use error::McpError;

pub use error::McpResult;

pub use messages::Capabilities;

pub use messages::Implementation;

pub use messages::InitializeRequest;

pub use messages::InitializeResponse;

pub use messages::InitializedNotification;

pub use messages::JsonRpcMessage;

pub use messages::JsonRpcNotification;

pub use messages::JsonRpcRequest;

pub use messages::JsonRpcResponse;

pub use messages::ProtocolVersion;

pub use transport::Transport;

pub use transport::TransportConfig;

pub use transport::TransportFactory;

pub use transport::TransportInfo;

Modules

client

MCP Client Implementation

error

Error types for MCP (Model Context Protocol) operations.

messages

MCP (Model Context Protocol) message types and JSON-RPC structures.

transport

MCP transport layer abstraction and implementations.

Constants

PROTOCOL_VERSION

Current MCP protocol version supported by this library

VERSION

Current version of the mcp-core library