npm package: @metaengine/mcp-server
Description: Model Context Protocol server enabling AI assistants to generate perfect code in 10 languages (TypeScript, Python, Go, C#, Java, Kotlin, Groovy, Scala, Swift, PHP) with zero syntax errors and automatic imports. Built for Claude Code and Claude Desktop.
Author: José A. Saldaña Perez
Latest version: 1.1.3

# MetaEngine MCP Server

[![npm version](https://img.shields.io/npm/v/@metaengine/mcp-server.svg)](https://www.npmjs.com/package/@metaengine/mcp-server)
[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
[![MCP](https://img.shields.io/badge/MCP-Compatible-green)](https://modelcontextprotocol.io)

**Turn one conversation into 50 consistent files. Claude architects, MetaEngine builds.**

A specialized tool for AI assistants. You describe what you need in natural language—Claude decides when structured generation makes sense and handles the rest.

## Install

Add to `~/.claude/mcp.json` (Claude Code) or Claude Desktop config:

```json
{
  "mcpServers": {
    "metaengine": {
      "command": "npx",
      "args": ["-y", "@metaengine/mcp-server"]
    }
  }
}
```

That's it. No API key, no signup, free to use.

## How It Works

**Without MCP (file-by-file):**
```
Claude: Generate User.ts → write → generate Order.ts → write → generate Product.ts → write...
Result: 20 sequential operations, growing context, potential pattern drift
```

**With MCP (structured):**
```
You: "Create User, Order, and Product models with services and repositories"
Claude: Constructs spec → MetaEngine returns all files → writes 15 files at once
Result: Instant, consistent, minimal context usage
```

You talk to Claude in natural language. Claude decides when structured generation makes sense and handles everything automatically.

## When Claude Uses This Tool

- Generating **20-100 interconnected files** where consistency matters
- **Multi-language projects** (same architecture in TypeScript, Python, Go, C#, Java, Kotlin, Groovy, Scala, Swift, PHP)
- **Pattern multiplication** (same structure applied to many entities)
- Complex **import management** across deep namespaces

## When Claude Generates Directly

- **1-15 files** — Claude's direct generation is faster for small tasks
- **Exploratory coding** where structure is still evolving
- **One-off scripts** and utilities
- **Rapid prototyping** where flexibility beats consistency

Both approaches are valid. Claude picks the right tool for the job.

## Real-World Workflows

### Cross-Language Test Parity
Point Claude at existing TypeScript tests → generate equivalent Go/Python/C# tests with same coverage in minutes instead of days.

### Multi-Entity CRUD System
"Generate User, Order, Product, Category with services, repositories, DTOs, and validators" → 50 files in ~60 seconds with perfect consistency.

### Polyglot Architecture
Same domain model across TypeScript frontend, Python API, Go microservices. One conversation, consistent types everywhere.

### Pattern Multiplication
Claude reads one well-designed service, generates the same pattern for 20 entities with identical structure.

## Performance

- **Instant generation** — 25-100 files in one call
- **3.8x faster** than file-by-file generation at scale
- **57% fewer tokens** — compact spec vs full file text

The tipping point is around 20 files—below that, Claude's direct generation is simpler.

## Languages Supported

TypeScript, Python, Go, C#, Java, Kotlin, Groovy, Scala, Swift, PHP

Each generates idiomatic code (data classes in Kotlin, case classes in Scala, structs in Swift, etc.)

## Privacy & Pricing

- **Free** — no API key, no signup, unlimited requests
- **Private** — specs sent for generation are never saved or logged
- **Local** — MCP server runs on your machine, MIT licensed

## Documentation

The AI guide is automatically embedded in the tool description on first use — no manual reading required. After the first successful call, the description swaps to a lightweight directive to minimize context usage.

- `METAENGINE_AI_GUIDE.md` — Critical rules, patterns, language notes, and common mistakes
- `EXAMPLES.md` — Real-world usage with input/output across all languages

## Common Questions

**Do I need to learn the JSON spec format?**
No. You talk to Claude in natural language. Claude constructs specs automatically.

**How is this different from Claude generating code directly?**
Claude Code is excellent at direct generation—and faster for small tasks. MetaEngine is a specialized tool for when you need structured generation at scale (20-100 files) with guaranteed consistency.

**Is my code sent to a server?**
Only the generation specs (JSON describing what to create). Your existing code never leaves your machine. Specs are never saved or logged.

**Can I use this with other AI assistants?**
Yes—any MCP-compatible assistant works. Currently that includes Claude Desktop and Claude Code.

## Links

- [NPM Package](https://www.npmjs.com/package/@metaengine/mcp-server)
- [Website](https://www.metaengine.eu/mcp)
- [MetaEngine Playground](https://www.metaengine.eu/playground)

## License

MIT