How can I deploy this server?

It's optimized for easy, one-command deployment to Google Cloud Run, utilizing a provided Dockerfile. You can also deploy directly from source.

Can I integrate it with the OpenAI Agent Builder?

Yes, you can add it as a new MCP Server in the Agent Builder by providing your Cloud Run URL and specifying the allowed tools.

How does it support OpenAI Agents?

It implements the `tools/list` and `tools/call` endpoints as per the MCP specification, enabling OpenAI agents to discover and interact with the exposed tool.

What is the FastAPI MCP Server?

It's a production-ready server built with FastAPI, designed to expose a single custom tool via OpenAI's Model Context Protocol (MCP) using JSON-RPC 2.0 over HTTP.

What are its core technical features?

It includes `jsonschema` input validation, proper JSON-RPC error handling, CORS support, optional API key authentication, and returns both `content` (text) and `structuredContent` (JSON).

FastAPI

Name: FastAPI
Author: bankszach

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Exposes a single tool via the OpenAI Model Context Protocol (MCP) using JSON-RPC 2.0 over HTTP.

This FastAPI-based server provides a minimal yet production-ready implementation of an MCP server. It's designed for deployment on Google Cloud Run and demonstrates the OpenAI Model Context Protocol by exposing a `get_time` tool. The server adheres strictly to the MCP specification for `tools/list` and `tools/call`, handling both human-readable content and machine-parseable structuredContent, complete with proper JSON-RPC error codes and input validation. It includes features like CORS support, optional API key authentication, a health check endpoint, and simple request logging, making it a robust foundation for integrating custom tools with AI agents.

Key Features

01Implements `tools/list` and `tools/call` to MCP specification

02Returns both content (text) and structuredContent (JSON)

03Includes JSON-RPC error codes and jsonschema input validation

04CORS enabled and optional API key authentication (x-api-key)

05Dockerfile and one-command Google Cloud Run deploy

060 GitHub stars

Use Cases

01Integrating a custom tool into an OpenAI Agent Builder

02Developing and testing custom tools compatible with the OpenAI Model Context Protocol

03Deploying a lightweight, serverless tool endpoint on Google Cloud Run