Atla MCP server

The Atla MCP Server provides a standardized interface for LLMs to interact with the Atla API for state-of-the-art LLMJ evaluation. This server implementation enables models to access Atla's evaluation capabilities through the Model Context Protocol.

Available Tools

The server provides two main evaluation tools:

• evaluate_llm_response: Evaluates an LLM's response to a prompt using a given evaluation criteria, returning a score and textual critique.
• evaluate_llm_response_on_multiple_criteria: Evaluates an LLM's response across multiple evaluation criteria, returning a list of evaluations with scores and critiques.

Installation Requirements

To use the Atla MCP Server, you'll need:

1. An Atla API key (available at Atla sign-in page or by creating a new account at Atla sign-up page)
2. The uv package manager for Python

Installing uv

The recommended way to manage the Python environment is with uv. Installation instructions can be found on the uv documentation site.

Running the Server

Once you have uv installed and your Atla API key ready, you can run the MCP server using:

ATLA_API_KEY=<your-api-key> uvx atla-mcp-server

Connecting to the Server

Using OpenAI Agents SDK

1. Install the OpenAI Agents SDK:

pip install openai-agents

2. Connect to the server in your Python code:

import os

from agents import Agent
from agents.mcp import MCPServerStdio

async with MCPServerStdio(
        params={
            "command": "uvx",
            "args": ["atla-mcp-server"],
            "env": {"ATLA_API_KEY": os.environ.get("ATLA_API_KEY")}
        }
    ) as atla_mcp_server:
    # Your code using the server
    pass

Configuring for Claude Desktop

1. Add the following to your claude_desktop_config.json file:

{
  "mcpServers": {
    "atla-mcp-server": {
      "command": "uvx",
      "args": ["atla-mcp-server"],
      "env": {
        "ATLA_API_KEY": "<your-atla-api-key>"
      }
    }
  }
}

2. Restart Claude Desktop to apply the changes.

You should now see options from atla-mcp-server in the list of available MCP tools.

Configuring for Cursor

Add the following to your .cursor/mcp.json file:

{
  "mcpServers": {
    "atla-mcp-server": {
      "command": "uvx",
      "args": ["atla-mcp-server"],
      "env": {
        "ATLA_API_KEY": "<your-atla-api-key>"
      }
    }
  }
}

After configuration, atla-mcp-server should appear in the list of available MCP servers in Cursor.

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 "atla-mcp-server" '{"command":"uvx","args":["atla-mcp-server"],"env":{"ATLA_API_KEY":"<your-atla-api-key>"}}'

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": {
        "atla-mcp-server": {
            "command": "uvx",
            "args": [
                "atla-mcp-server"
            ],
            "env": {
                "ATLA_API_KEY": "<your-atla-api-key>"
            }
        }
    }
}

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": {
        "atla-mcp-server": {
            "command": "uvx",
            "args": [
                "atla-mcp-server"
            ],
            "env": {
                "ATLA_API_KEY": "<your-atla-api-key>"
            }
        }
    }
}

3. Restart Claude Desktop for the changes to take effect