openapi2mcp

A tool to convert OpenAPI 3.x specifications to FastMCP servers.

Installation

poetry install

Usage / Commands

openapi2mcp provides a command-line interface to generate and manage MCP server code from OpenAPI specifications.

generate

Generates the MCP server Python code from an OpenAPI specification file.

Syntax:

openapi2mcp generate [OPTIONS]

Options:

• -i, --input-file PATH: Path to the OpenAPI specification file (JSON or YAML). (Required)
• -o, --output-file PATH: Path to the output Python file for the generated MCP server. (Required)
• -t, --transport [stdio|google_pubsub]: The transport mechanism for the MCP server. (Default: stdio)
• --llms-txt-file PATH: Optional path to generate an llms.txt file, which provides a description of the generated tools and resources for language models. If not specified, llms.txt will be created in the same directory as the output server file.
• --mount TEXT: Optional mount path for resources (e.g., /myapi/v1). (Default: "")

Example:

openapi2mcp generate --input-file examples/example_openapi.yaml --output-file generated_server.py --transport stdio --mount "/api"

This command will parse examples/example_openapi.yaml, generate an MCP server file named generated_server.py using the stdio transport, and set the resource mount path to /api. It will also generate an llms.txt file in the same directory as generated_server.py.

check

Checks a generated MCP server Python file for basic code validity, including syntax and presence of key MCP patterns.

Syntax:

openapi2mcp check --server-file PATH

Options:

• --server-file PATH: Path to the generated MCP server Python file to check. (Required)

Example:

openapi2mcp check --server-file generated_server.py

version

Displays the version of the openapi2mcp tool.

Syntax:

openapi2mcp version

Example:

openapi2mcp version

Examples

See example implementations:

• HTTP Server
• SSE Server
• STDIO Server
• Sample OpenAPI spec

Project Structure

• openapi2mcp/parser.py: OpenAPI specification parser
• openapi2mcp/generator.py: FastMCP server code generator
• openapi2mcp/cli.py: Command-line interface

License

MIT - See LICENSE