Crate mcp_host

Crate mcp_host 

Source
Expand description

mcp-host: Production-grade MCP server implementation

This crate provides a comprehensive Model Context Protocol (MCP) server implementation with sophisticated features like middleware chains, task management, progress tracking, and more.

§Quick Start

ⓘ
use mcp_host::prelude::*;
use async_trait::async_trait;

struct MyTool;

#[async_trait]
impl Tool for MyTool {
    fn name(&self) -> &str { "my_tool" }
    fn input_schema(&self) -> serde_json::Value {
        serde_json::json!({
            "type": "object",
            "properties": {
                "input": { "type": "string" }
            }
        })
    }
    async fn execute(&self, ctx: ExecutionContext<'_>) -> Result<Vec<Box<dyn Content>>, ToolError> {
        Ok(vec![Box::new(TextContent::new("Hello!"))])
    }
}

When using the macros feature, you can use procedural derive macros for reduced boilerplate:

ⓘ
use mcp_host::prelude::*;

#[derive(McpTool)]
#[mcp(name = "my_tool", description = "Does something useful")]
struct MyTool {
    #[mcp(skip)]
    state: SomeInternalState,  // Not included in schema
    input: String,              // Included in schema
}

// User must implement execute manually
impl MyTool {
    async fn run(&self, ctx: ExecutionContext<'_>) -> Result<Vec<Box<dyn Content>>, ToolError> {
        Ok(vec![Box::new(TextContent::new(&self.input))])
    }
}

Enable derive macros with: mcp-host = { version = "0.1", features = ["macros"] }

Modules§

content
Content types and builders
logging
Logging infrastructure for MCP notifications
managers
Manager components TODO: Phase 4
prelude
protocol
MCP protocol types and utilities
registry
Registry components TODO: Phase 5
server
Server implementation
transport
MCP transport implementations
utils
Utility functions for file handling, path security, and encoding

Macros§

const_string
Macro for creating compile-time constant string types