Harness MCP Server (Beta)

The Harness Model Context Protocol (MCP) Server (in Beta) enables integration with Harness tools, providing endpoints for pipelines, pull requests, and more. This guide outlines the installation, configuration, and usage of the MCP server.

Introduction

What is MCP?

MCP (Model Context Protocol) is an open standard for AI agents to interact with tools and services using a unified protocol. Instead of building custom adapters or connectors for each tool, MCP provides a consistent interface that allows AI agents to communicate seamlessly with various tools, including Harness services.

In simpler terms: MCP standardizes how AI agents talk to software tools, enabling interoperability without requiring custom code for each integration.

Why MCP?

Harness is building a diverse set of AI agents that need access to platform data and services. Additionally, customers may have their own agents that require interaction with Harness entities to perform specific tasks.

MCP solves this problem by:

• Standardizing communication: A single interface for connecting agents to Harness tools, reducing implementation complexity.
• Supporting external tools: Seamless integration with third-party tools like Windsurf, Cursor, and Claude Desktop, eliminating the need for custom adapters.
• Ensuring consistency: A common interface reduces duplication and potential inconsistencies across different agents and tools.

MCP vs. Tool/Function Calling

Why not just use function calls for each API?

1. Limited Support for External Tools: Function calling is often restricted to the model’s internal tools. MCP enables integration with external tools like Windsurf, Cursor, and Claude Desktop.
2. Inconsistent Implementations: Without MCP, each agent would need to implement the same logic in different languages/frameworks, increasing the risk of errors.
3. Scalability and Reuse: MCP provides a standardized protocol, allowing reusable implementations across various agents and tools.

Requirements

• Harness API Token: Generate one through the Harness UI. Learn more: Manage API Keys
• Go 1.23 or later: Ensure Go is installed on your system.

Video Walkthrough (Installation and Setup)

Configuration

Windsurf Configuration

Using Source

{
  "mcpServers": {
    "harness": {
      "command": "/path/to/harness-mcp-server",
      "args": ["stdio"],
      "env": {
        "HARNESS_API_KEY": "your_api_key",
        "HARNESS_DEFAULT_ORG_ID": "your_org_id",
        "HARNESS_DEFAULT_PROJECT_ID": "your_project_id",
        "HARNESS_BASE_URL": "<if-needed>"
      }
    }
  }
}

Using Docker

{
  "mcpServers": {
    "harness": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "HARNESS_API_KEY",
        "-e",
        "HARNESS_DEFAULT_ORG_ID",
        "-e",
        "HARNESS_DEFAULT_PROJECT_ID",
        "-e",
        "HARNESS_BASE_URL",
        "harness/mcp-server",
        "stdio"
      ],
      "env": {
        "HARNESS_API_KEY": "<YOUR_API_KEY>",
        "HARNESS_DEFAULT_ORG_ID": "<YOUR_ORG_ID>",
        "HARNESS_DEFAULT_PROJECT_ID": "<YOUR_PROJECT_ID>",
        "HARNESS_BASE_URL": "<YOUR_BASE_URL>"
      }
    }
  }
}

Windsurf MCP Guide

Cursor Configuration

{
  "mcpServers": {
    "harness": {
      "command": "/path/to/harness-mcp-server",
      "args": ["stdio"],
      "env": {
        "HARNESS_API_KEY": "your_api_key",
        "HARNESS_DEFAULT_ORG_ID": "your_org_id",
        "HARNESS_DEFAULT_PROJECT_ID": "your_project_id",
        "HARNESS_BASE_URL": "<if-needed>"
      }
    }
  }
}

Cursor MCP Guide

VS Code Configuration

{
  "mcp": {
    "servers": {
      "harness": {
        "command": "docker",
        "args": [
          "run",
          "-i",
          "--rm",
          "-e",
          "YjJmMGNkNDAyOGQ2YWQ4ZjI2MzA4NzMxNTlhOTgyNWQ=",
          "-e",
          "HARNESS_DEFAULT_ORG_ID",
          "-e",
          "HARNESS_DEFAULT_PROJECT_ID",
          "-e",
          "HARNESS_BASE_URL",
          "harness/mcp-server",
          "stdio"
        ],
        "env": {
          "HARNESS_API_KEY": "<YOUR_API_KEY>",
          "HARNESS_DEFAULT_ORG_ID": "<YOUR_ORG_ID>",
          "HARNESS_DEFAULT_PROJECT_ID": "<YOUR_PROJECT_ID>",
          "HARNESS_BASE_URL": "<YOUR_BASE_URL>"
        }
      }
    }
  }
}

VS Code MCP Guide

Using Claude Code

claude mcp add harness -- docker run -i --rm \
  -e HARNESS_API_KEY=your_api_key \
  -e HARNESS_DEFAULT_ORG_ID=your_org_id \
  -e HARNESS_DEFAULT_PROJECT_ID=your_project_id \
  -e HARNESS_BASE_URL=your_base_url \
  harness/mcp-server stdio

Claude Code MCP Guide

Building from Source

1. Clone the repository:

git clone https://github.com/harness/mcp-server  
cd mcp-server

2. Build the binary:

go build -o cmd/harness-mcp-server/harness-mcp-server ./cmd/harness-mcp-server

3. Run the server:

HARNESS_API_KEY=your_api_key \
./cmd/harness-mcp-server/harness-mcp-server stdio

Use Docker Image

Alternatively, you can use the pre-built Docker image:

docker run -i --rm \
  -e HARNESS_API_KEY=your_api_key \
  -e HARNESS_DEFAULT_ORG_ID=your_org_id \
  -e HARNESS_DEFAULT_PROJECT_ID=your_project_id \
  -e HARNESS_BASE_URL=your_base_url \
  harness/mcp-server stdio

Authentication

Set the HARNESS_API_KEY environment variable for authentication. Learn more: Manage API Keys.

export HARNESS_API_KEY=<your_api_key>

Command Line Arguments

Please refer to the Harness MCP Server Command Line Arguments documentation for a full list of available command line arguments.

Environment Variables

You can customize and configure your Harness MCP server with environment variables. For a full list of options, visit the MCP Environment Variables documentation.

MCP Server Tool Sets Overview

MCP Tools allow servers to expose executable functions that can be invoked by clients and used by LLMs to perform actions.

For a full list of tools and toolsets available, visit the Harness MCP toolsets documentation.

By default, we currently support the following set of tools under the default toolset:

• get_connector_details: Get details of a specific connector
• list_connector_catalogue: List the Harness connector catalogue
• list_connectors: List connectors with filtering options
• list_pipelines: List pipelines in a repository
• get_pipeline: Get details of a specific pipeline
• get_execution: Get details of a specific pipeline execution
• list_executions: List pipeline executions
• fetch_execution_url: Fetch the execution URL for a pipeline execution
• list_dashboards: Lists all available Harness dashboards
• get_dashboard_data: Retrieves the data from a specific Harness dashboard

Use Cases

Using Tools Demo

Watch the use case demo for a walkthrough of MCP server functionality:

Using Artifact Registry Tools Demo

Watch this demo to see the use of Artifact Registry tools in action.

References

• Harness MCP Server Repo
• Model Context Protocol Overview