API Tester MCP Server

This is a Model Context Protocol (MCP) server that allows Claude to make API requests on your behalf. It provides tools for testing various APIs, including a dedicated integration with OpenAI's APIs.

Features

Make HTTP requests (GET, POST, PUT, DELETE) to any API
Test OpenAI's GPT models without sharing your API key in the chat
Generate images with DALL-E
Properly formatted responses for easy reading

Related MCP server: Contentful MCP Server

Setup

Prerequisites

Python 3.10 or higher
MCP SDK 1.2.0 or higher

Installation

Install the required dependencies:

pip install "mcp[cli]" httpx python-dotenv

Set your OpenAI API key using one of these methods:

Option 1: Environment Variables

# On Windows (PowerShell) $env:OPENAI_API_KEY = "your-api-key" # On Windows (Command Prompt) set OPENAI_API_KEY=your-api-key # On macOS/Linux export OPENAI_API_KEY="your-api-key"

Option 2: Using a .env File (Recommended)

Create a .env file in the project directory (copy from .env.example):

OPENAI_API_KEY=your_openai_api_key_here

Running the Server

python main.py

Using with Claude

Once your server is running, you can connect it to Claude for Desktop by configuring it in the Claude Desktop config file.

Example Prompts

General API Testing

Use the get_request tool to fetch data from https://jsonplaceholder.typicode.com/posts/1

Use the post_request tool to send data to https://jsonplaceholder.typicode.com/posts with this JSON body: {"title": "Test Post", "body": "This is a test", "userId": 1}

Using OpenAI Tools

Use the openai_chat_completion tool with: prompt: "Write a short poem about artificial intelligence" system_message: "You are a helpful assistant that writes creative poetry" model: "gpt-4"

Use the openai_image_generation tool with: prompt: "A futuristic city with flying cars and tall glass buildings at sunset" size: "1024x1024"

Available Tools

General API Tools

get_request: Make GET requests to any URL
post_request: Make POST requests with JSON bodies
put_request: Make PUT requests with JSON bodies
delete_request: Make DELETE requests

OpenAI-Specific Tools

openai_chat_completion: Generate text using OpenAI's chat models
openai_image_generation: Generate images using DALL-E

Security Notes

Your OpenAI API key is stored in the server and not exposed in the chat
API usage will count against your OpenAI quota and may incur charges
For production use, always set the API key as an environment variable or use a .env file
The .env file is included in .gitignore to prevent accidentally committing your API key