mcp-codegen

mcp-execution-codegen

Progressive loading TypeScript code generation for MCP tools. Achieves 98% token savings by generating one file per tool.

Installation

[dependencies]
mcp-execution-codegen = "0.6"

Or with cargo-add:

cargo add mcp-execution-codegen

Important

Requires Rust 1.89 or later.

Usage

Progressive Loading Generation

use mcp_execution_codegen::progressive::ProgressiveGenerator;
use mcp_execution_introspector::Introspector;
use mcp_execution_core::{ServerId, ServerConfig};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // 1. Introspect MCP server
    let mut introspector = Introspector::new();
    let server_id = ServerId::new("github");
    let config = ServerConfig::builder()
        .command("github-mcp-execution-server".to_string())
        .build();
    let info = introspector.discover_server(server_id, &config).await?;

    // 2. Generate progressive loading files
    let generator = ProgressiveGenerator::new()?;
    let code = generator.generate(&info)?;

    println!("Generated {} files", code.file_count());
    Ok(())
}

Tip

Generated files include: one .ts file per tool, index.ts re-exports, and _runtime/mcp-bridge.ts helper.

Token Savings

Approach	Tokens	Savings
Traditional (all tools)	~30,000	-
Progressive (1 tool)	~500-1,500	98%

Generated TypeScript Structure

Each tool file includes full TypeScript interfaces:

/**
 * Creates a new issue in a GitHub repository
 * @param params - Tool parameters
 * @returns Tool execution result
 */
export async function createIssue(
  params: CreateIssueParams
): Promise<CreateIssueResult> {
  return await callMCPTool('github', 'create_issue', params);
}

export interface CreateIssueParams {
  /** Repository in format "owner/repo" */
  repo: string;
  /** Issue title */
  title: string;
  /** Issue body (optional) */
  body?: string;
}

Features

• One File Per Tool: Separate TypeScript file for each MCP tool
• Type-Safe Interfaces: Full TypeScript parameter and result types
• JSDoc Documentation: Complete documentation from MCP schemas
• 98% Token Savings: Load only the tools you need
• Handlebars Templates: Customizable code generation

Type Conversion

JSON Schema types are converted to TypeScript:

JSON Schema	TypeScript
string	string
number	number
boolean	boolean
array	T[]
object	{ [key: string]: T }

Note

Optional parameters use ? suffix in TypeScript interfaces.

Performance

Metric	Target	Achieved
10 tools	<100ms	0.19ms (526x faster)
50 tools	<20ms	0.97ms (20.6x faster)
VFS export	<10ms	1.2ms (8.3x faster)

Related Crates

This crate is part of the mcp-execution workspace:

• mcp-execution-core - Foundation types
• mcp-execution-introspector - MCP server analysis
• mcp-execution-files - Virtual filesystem for output

MSRV Policy

Minimum Supported Rust Version: 1.89

MSRV increases are considered minor version bumps.

License

Licensed under either of Apache License 2.0 or MIT license at your option.