k6 Load Testing MCP server

The k6-mcp-server provides a Model Context Protocol (MCP) implementation that allows you to run k6 load tests directly through LLM clients like Claude Desktop, Cursor, or Windsurf. It creates a seamless connection between large language models and k6 performance testing functionality.

Prerequisites

Before getting started, make sure you have installed:

• Python 3.12 or higher
• k6 load testing tool (Installation guide)
• uv package manager (Installation guide)

Installation

1. Clone the repository:

git clone https://github.com/qainsights/k6-mcp-server.git

2. Install the required dependencies:

uv pip install -r requirements.txt

3. Set up environment variables (optional): Create a .env file in the project root:

K6_BIN=/path/to/k6  # Optional: defaults to 'k6' in system PATH

Configuration

To configure your MCP client to use the k6-mcp-server, add the following configuration to your MCP client settings:

{
  "mcpServers": {
    "k6": {
      "command": "/path/to/bin/uv",
      "args": [
        "--directory",
        "/path/to/k6-mcp-server",
        "run",
        "k6_server.py"
      ]
    }
  }
}

Make sure to replace /path/to/bin/uv and /path/to/k6-mcp-server with the actual paths on your system.

Running Tests

Create a Test Script

First, create a k6 test script file. For example, test.js:

import http from "k6/http";
import { sleep } from "k6";

export default function () {
  http.get("http://test.k6.io");
  sleep(1);
}

Execute Tests Through an LLM

Once your MCP server is configured, you can ask your LLM to run tests using natural language commands:

• For a basic test: "Run k6 test for hello.js"
• For more specific parameters: "Run a k6 test for api_test.js with 20 virtual users for 1 minute"

Available Commands

The k6-mcp-server provides two main functions:

Basic Test Execution

execute_k6_test(
    script_file: str,
    duration: str = "30s",  # Optional
    vus: int = 10          # Optional
)

This command runs a k6 test with default settings (30 seconds duration and 10 virtual users) if not specified.

Custom Test Execution

execute_k6_test_with_options(
    script_file: str,
    duration: str,
    vus: int
)

This command requires you to specify both the duration and number of virtual users for your test.

Use Cases

The k6-mcp-server is particularly useful for:

• Having LLMs analyze test results and provide insights
• Debugging load test issues through conversational interfaces
• Quickly running performance tests without leaving your LLM environment

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "k6" '{"command":"/path/to/bin/uv","args":["--directory","/path/to/k6-mcp-server","run","k6_server.py"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "k6": {
            "command": "/path/to/bin/uv",
            "args": [
                "--directory",
                "/path/to/k6-mcp-server",
                "run",
                "k6_server.py"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "k6": {
            "command": "/path/to/bin/uv",
            "args": [
                "--directory",
                "/path/to/k6-mcp-server",
                "run",
                "k6_server.py"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect