API Testing Using MCP Server (End User Guide)

A ready-to-use Model Context Protocol (MCP) server for HTTP API testing, powered by Playwright. This guide helps you install, configure, and run the MCP server locally as an npm package.

📋 Table of Contents

• Overview

• Prerequisites

• Setup

• Configurations

• Usage

• Example scenarios and prompts for MCP server usage

• Upcoming enhancements

• Troubleshooting

• Support

Related MCP server: Playwright MCP Server

🌟 Overview

The Playwright API MCP Server enables API testing via the Model Context Protocol. It supports GET, POST, PUT, and DELETE requests.

📋 Prerequisites

• Node.js: v18.0.0 or higher.

• npm: Comes with Node.js.

• VS Code: MCP-compatible client.

• Github Copilot: Make sure the GitHub Copilot extension is installed and enabled in VS Code. Watch the video to understand how to enable Github Copilot: https://www.youtube.com/watch?v=etP5wq4Zl20

• How to use Github Copilot for free Watch the Video: https://www.youtube.com/watch?v=X_Aet9ndh_Y

🚀 Setup

1. Create a Node.js Project in VS Code:

   • Create a new folder with a meaningful name (e.g. my-project).

   • Open the folder in Visual Studio Code.

   • Launch the integrated terminal (via View > Terminal).

   • Choose your preferred shell (e.g. Git Bash, Command Prompt, or PowerShell).

   • Run the following command to initialise the project:

     npm init -y

   • This will generate a package.json file with default settings

2. Install the MCP Server Package

   • Now, run the below command to install the mcp server package.

     npm i @automate-io/api-testing-mcp@latest

⚙️ Configurations

1. Open your project folder in VS Code

2. If the mcp.json file does not already exist, create it inside the root/.vscode/ directory. If the file is already present, you can skip this step

3. Add the api-testing-mcp configuration under the servers key in the mcp.json file, as shown below

   {
     "servers": {
       "api-testing-mcp": {
         "type": "stdio",
         "command": "node",
         "args": ["node_modules/@automate-io/api-testing-mcp/dist/server.js"],
         "cwd": "${workspaceFolder}"
       }
     },
     "inputs": []
   }

• ❗Important Note:If you are working in a monorepo, ensure the args field in your mcp.json file is correctly configured. Refer to the Monorepo MCP Configuration guide for detailed instructions. If your test code resides in a standalone repository, no changes are needed, you are good to go.

📖 Getting started with MCP testing

1. Start the MCP Server

• Click the highlighted start button in the mcp.json file as shown below to start the MCP server.

2. Input the prompt

• Open GitHub Copilot chat window in VS Code with Agent mode selected.

• Enter a prompt that outlines the API you wish to test.

✅ Example scenarios and prompts for MCP server usage

• Scenario 1 : To test all endpoints in one go.

• Scenario 2 : To test a single endpoint.

⏭️ Upcoming enhancements

• Implement schema validations for response payloads

• Add reusable resources to support API testing workflows

• Introduce predefined prompts to streamline common scenarios

• Provide a sample HTML test report template to guide LLm about the layout and formatting

• Refactor existing logic and implement robust error handling to improve reliability and maintainability

🔧 Troubleshooting

• Server not running?
  Double-check your MCP client configuration.

• Module not found?
  Reinstall the package:

  npm i @automate-io/api-testing-mcp@latest

🆘 Support

• Review this guide and your MCP client documentation.

• For issues, open GitHub Issues here.

• Consult Model Context Protocol Documentation.

👍 Enjoy exploring and validating your APIs !