OpenAPI Sync MCP

A high-performance MCP server for OpenAPI specifications. Parse, diff, track dependencies, and generate code - all from your AI assistant.

Built with Rust for speed and minimal resource usage.

Features

• Dependency Graph - Know which endpoints break when you change a schema
• Smart Diff - Detect breaking changes before they hit production
• Paginated Parsing - Handle massive specs without overwhelming context
• 24h Cache - Fast repeated queries with HTTP cache support
• Multi-target Codegen - TypeScript, Rust, Python from one spec

Quick Start

npm install -g @jhlee0409/openapi-sync-mcp

Add to ~/.claude/settings.json:

{
  "mcpServers": {
    "oas": {
      "command": "openapi-sync-mcp"
    }
  }
}

Tools

| Tool | Description | |------|-------------| | oas_parse | Parse and validate OpenAPI spec (with pagination) | | oas_deps | Find affected endpoints when a schema changes | | oas_diff | Compare two spec versions, detect breaking changes | | oas_status | Check cache status | | oas_generate | Generate TypeScript/Rust/Python code |

Code Generation Targets

typescript-types · typescript-fetch · typescript-axios · typescript-react-query · rust-serde · rust-reqwest · python-pydantic · python-httpx

Installation

# npm (recommended)
npm install -g @jhlee0409/openapi-sync-mcp

# Cargo
cargo install openapi-sync-mcp

# Or download from GitHub Releases

Troubleshooting

Server not responding?

chmod +x openapi-sync-mcp
echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' | openapi-sync-mcp

Cache issues? Delete .openapi-sync.cache.json or use use_cache: false.

Development

cargo test          # Run tests
cargo fmt --check   # Check formatting
cargo clippy        # Lint

License

MIT

Related

• claude-plugins - Plugin commands (/oas:*) for enhanced workflow