openmcp

# OpenMCP OpenMCP makes it easy to turn any OpenAPI specification into an MCP server, and to remix many MCP servers into a single server with just the tools you need. It supports stdio and sse transports, and works with all of the major chat clients. To get started, run this command: ```bash npx -y openmcp install <url or file path to openapi specification> --client <chat client> ``` For example, to add the ability to query the weather from Cursor, you could run this: ```bash # openmcp will prompt you for a security key since this api requires it - but the value can be any string npx -y openmcp install https://api.weather.gov/openapi.json --client cursor ``` Running the install command will create an `openmcp.json` file for you, and add the openmcp server to your the mcp config of your target (cursor, claude, etc). Running install again will update any existing `openmcp.json` file, if present. ### openmcp.json format The `openmcp.json` file describes the servers that should be started, auth configuration for each, and which tools you want to expose for each server. Bellow is a fully annotated example that mixes an openapi based server with a stdio server. Running openmcp with this config would result in an mcp server with two tools - a tool to get the weather forecast, and a tool to make queries to a local postgres database. ```jsonc { // The configs object is a map of variable names to values. These variables can be referenced in the servers object below. // If a value is not set, openmcp will attempt to read from an environment variable of the same name. "configs": { "weather-gov-api": { "WEATHER_GOV_API_API_KEY": "foo", }, "postgres": { // Or leave blank to read from the environment variable "POSTGRES_URL" "POSTGRES_URL": "postgresql://localhost/mydb", }, }, "servers": { // Example of an openapi server "weather-gov-api": { "type": "openapi", // The openapi specification can be a url or a local file path "openapi": "https://api.weather.gov/openapi.json", // The base url of the server "serverUrl": "https://api.weather.gov", // Optional headers to send with requests to the server. They can reference values from the configs object above. "headers": { "User-Agent": "{{WEATHER_GOV_API_API_KEY}}", }, // Optional query parameters to send with requests to the server. "query": {}, // The tools to expose for this server (by operationId). Leaving this empty will expose all tools. "tools": ["zone_forecast"], }, // Example of a stdio server "postgres": { "command": "npx", "args": ["-y", "@modelcontextprotocol/server-postgres", "{{POSTGRES_URL}}"], // The tools allowlist also works with stdio servers. In this case we only expose the relatively safe "query" tool. "tools": ["query"], }, }, } ``` ### Running the server The install command will handle this for you, but if you'd like to run an openmcp server manually you can do so with this command: ```bash npx -y openmcp run --config <path to openmcp.json config> ```