Crate model_context_protocol_macros 

Procedural macros for MCP server and tool definitions.

This crate provides macros to reduce boilerplate when defining MCP servers:

• #[mcp_server] - Define server metadata and collect tools from impl blocks
• #[mcp_tool] - Mark a method as an MCP tool (used within #[mcp_server] impl blocks)
• #[param(...)] - Mark a parameter with description for the tool schema

Example

use mcp::macros::mcp_server;

#[mcp_server(name = "calculator", version = "1.0.0")]
pub struct Calculator;

#[mcp_server]
impl Calculator {
    #[mcp_tool("Add two numbers together")]
    pub fn add(
        &self,
        #[param("The first number")] a: f64,
        #[param("The second number")] b: f64,
    ) -> f64 {
        a + b
    }
}

Note: #[mcp_tool] and #[param] are inert marker attributes processed by #[mcp_server]. They should only be used within impl blocks marked with #[mcp_server].

Attribute Macros

mcp_server

Marks a struct as an MCP server or an impl block as containing MCP tools.

mcp_tool

Marks a method as an MCP tool.