MCP REST API Tester

A TypeScript-based MCP server that enables testing of REST APIs through Claude, Cline and other MCP clients. This tool allows you to test and interact with any REST API endpoints directly from your development environment.

Installation

Install the package globally:

npm install -g dkmaker-mcp-rest-api

Configuration

Cline Custom Instructions

To ensure Cline understands how to effectively use this tool, add the following to your Cline custom instructions (Settings > Custom Instructions):

# REST API Testing Instructions
The test_request tool enables testing, debugging, and interacting with REST API endpoints. The tool provides comprehensive request/response information and handles authentication automatically.
When to Use
Testing specific API endpoints
Debugging API responses
Verifying API functionality
Checking response times
Validating request/response formats
Testing local development servers
Testing API sequences
Verifying error handling
Key Features
Supports GET, POST, PUT, DELETE, PATCH methods
Handles authentication (Basic, Bearer, API Key)
Normalizes endpoints automatically
Provides detailed response information
Configurable SSL verification and response limits
Resources
The following resources provide detailed documentation:
examples: Usage examples and common patterns
response-format: Response structure and fields
config: Configuration options and setup guide
Access these resources to understand usage, response formats, and configuration options.
Important Notes
Review API implementation for expected behavior
Handle sensitive data appropriately
Consider rate limits and API constraints
Restart server after configuration changes

MCP Server Configuration

While these instructions are for Cline, the server should work with any MCP implementation. Configure based on your operating system:

Windows

⚠️ IMPORTANT: Due to a known issue with Windows path resolution (issue #40), you must use the full path instead of %APPDATA%.

Add to C:\Users\\AppData\Roaming\Code\User\globalStorage\saoudrizwan.claude-dev\settings\cline_mcp_settings.json:

{
  "mcpServers": {
    "rest-api": {
      "command": "node",
      "args": [
        "C:/Users//AppData/Roaming/npm/node_modules/dkmaker-mcp-rest-api/build/index.js"
      ],
      "env": {
        "REST_BASE_URL": "https://api.example.com",
        // Basic Auth
        "AUTH_BASIC_USERNAME": "your-username",
        "AUTH_BASIC_PASSWORD": "your-password",
        // OR Bearer Token
        "AUTH_BEARER": "your-token",
        // OR API Key
        "AUTH_APIKEY_HEADER_NAME": "X-API-Key",
        "AUTH_APIKEY_VALUE": "your-api-key",
        // SSL Verification (enabled by default)
        "REST_ENABLE_SSL_VERIFY": "false", // Set to false to disable SSL verification for self-signed certificates
        // Response Size Limit (optional, defaults to 10000 bytes)
        "REST_RESPONSE_SIZE_LIMIT": "10000", // Maximum response size in bytes
        // Custom Headers (optional)
        "HEADER_X-API-Version": "2.0",
        "HEADER_Custom-Client": "my-client",
        "HEADER_Accept": "application/json"
      }
    }
  }
}

macOS

Add to ~/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json:

{
  "mcpServers": {
    "rest-api": {
      "command": "npx",
      "args": [
        "-y",
        "dkmaker-mcp-rest-api"
      ],
      "env": {
        "REST_BASE_URL": "https://api.example.com",
        // Basic Auth
        "AUTH_BASIC_USERNAME": "your-username",
        "AUTH_BASIC_PASSWORD": "your-password",
        // OR Bearer Token
        "AUTH_BEARER": "your-token",
        // OR API Key
        "AUTH_APIKEY_HEADER_NAME": "X-API-Key",
        "AUTH_APIKEY_VALUE": "your-api-key",
        // SSL Verification (enabled by default)
        "REST_ENABLE_SSL_VERIFY": "false", // Set to false to disable SSL verification for self-signed certificates
        // Custom Headers (optional)
        "HEADER_X-API-Version": "2.0",
        "HEADER_Custom-Client": "my-client",
        "HEADER_Accept": "application/json"
      }
    }
  }
}

Note: Replace the environment variables with your actual values. Only configure one authentication method at a time:

Basic Authentication (username/password)
Bearer Token (if Basic Auth is not configured)
API Key (if neither Basic Auth nor Bearer Token is configured)

Features

Test REST API endpoints with different HTTP methods
Support for GET, POST, PUT, DELETE, and PATCH requests
Detailed response information including status, headers, and body
Custom Headers:
Global headers via HEADER_* environment variables
Case-insensitive prefix (HEADER_, header_, HeAdEr_)
Case preservation for header names
Priority-based application (per-request > auth > custom)
Request body handling for POST/PUT methods
Response Size Management:
Automatic response size limiting (default: 10KB/10000 bytes)
Configurable size limit via REST_RESPONSE_SIZE_LIMIT environment variable
Clear truncation metadata when responses exceed limit
Preserves response structure while only truncating body content

SSL Certificate Verification:
Enabled by default for secure operation
Can be disabled for self-signed certificates or development environments
Control via REST_ENABLE_SSL_VERIFY environment variable
Multiple authentication methods:
Basic Authentication (username/password)
Bearer Token Authentication
API Key Authentication (custom header)

Usage Examples

Once installed and configured, you can use the REST API Tester through Cline to test your API endpoints:

// Test a GET endpoint
use_mcp_tool('rest-api', 'test_request', {
  "method": "GET",
  "endpoint": "/users"
});
// Test a POST endpoint with body
use_mcp_tool('rest-api', 'test_request', {
  "method": "POST",
  "endpoint": "/users",
  "body": {
    "name": "John Doe",
    "email": "john@example.com"
  }
});// Test with custom headers
use_mcp_tool('rest-api', 'test_request', {
  "method": "GET",
  "endpoint": "/products",
  "headers": {
    "Accept-Language": "en-US",
    "X-Custom-Header": "custom-value"
  }
});

Development

Clone the repository:

git clone https://github.com/zenturacp/mcp-rest-api.git
cd mcp-rest-api

Install dependencies:

npm install

Build the project:

npm run build

For development with auto-rebuild:

npm run watch

License

This project is licensed under the MIT License - see the LICENSE file for details.

--- Tranlated By Open Ai Tx | Last indexed: 2026-05-06 ---