Atla MCP Server

An MCP server implementation that provides a standardized interface for LLMs to interact with the Atla SDK and use our state-of-the-art evaluation models.

Features

• Evaluate individual responses with Selene 1
• Run batch evaluations with Selene 1
• List available evaluation metrics, create new ones or fetch them by name

Installation

1. Fork the repository and clone it locally in some directory. This will define your path/to/atla-mcp-server

git clone https://github.com/yourusername/atla-mcp-server.git
cd atla-mcp-server
pwd
# /path/to/atla-mcp-server

2. Install uv on your system into /path/to/uv if you don't have it already - you can find instructions here. For instance on MacOS:

brew install uv
which uv
# /path/to/uv

3. Install requirements into a virtual environment in /path/to/atla-mcp-server

uv venv
uv sync

4. Add your ATLA_API_KEY into your environment - you can find yours here. For instance on MacOS:

export ATLA_API_KEY=<your-atla-api-key> >> ~/.zshrc
source ~/.zshrc
echo $ATLA_API_KEY
# <your-atla-api-key>

• If you are building with OpenAI agents, you will also need an OPENAI_API_KEY in your environment

Usage

Use with OpenAI Agents SDK

The atla-mcp-server can be used with the OpenAI agents SDK as follows:

from agents import Agent
from agents.mcp import MCPServerStdio
import os
atla_api_key = os.environ.get("ATLA_API_KEY", "<your_atla_api_key>") # You can also manually set your ATLA_API_KEY here

async with MCPServerStdio(
        params={
            "command": "python",
            "args": ["/path/to/atla-mcp-server/atla-mcp-server.py"],
            "env": {"ATLA_API_KEY":atla_api_key}
        }
    ) as atla_mcp_server:
        # Create an agent with the Atla evaluation server
        agent = Agent(
            name="AssistantWithAtlaEval",
            instructions="""
            You are a helpful assistant. Your goal is to provide high-quality responses to user requests.
            You can use the Atla evaluation tool to improve your responses.
            """,
            mcp_servers=[atla_mcp_server], # You can equip any Agent with Atla's MCP server like this
            model="gpt-4o-mini"
        )

For an example, run the following from /path/to/atla-mcp-server:

uv run examples/agent_with_atla_eval.py "Write a one-line poem about the ocean. Evaluate it with atla for cliche and improve it once using the feedback."

You can also try out the notebook version of this example in examples/agent_notebook.ipynb.

Use with Claude Desktop

• Download Claude Desktop from here (this is a local server, and won’t work with claude.ai on web)
• Click on Claude → Settings… → Developer → Edit Config
• Add the following to the claude_desktop_config.json file (ensure that you replace <your-atla-api-key> with your actual Atla API key):

{
	"mcpServers": {
		"atla-mcp-server": {
			"command": "/path/to/uv",
			"args": [
			"--directory",
			"/path/to/atla-mcp-server",
			"run",
			"atla-mcp-server.py"
			],
			"env": {
			"ATLA_API_KEY": "<your-atla-api-key>"
			}
		}
	}
}

• When you restart Claude Desktop, you should see atla-mcp-server in the list of available MCP servers, and 5 tools available to Claude.
• Example prompt to Claude: Write a poem, evaluate it with atla for helpfulness

Use with Cursor

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

{
	"mcpServers": {
		"atla-mcp-server": {
			"command": "/path/to/uv",
			"args": [
			"--directory",
			"/path/to/atla-mcp-server",
			"run",
			"atla-mcp-server.py"
			],
			"env": {
			"ATLA_API_KEY": "<your-atla-api-key>"
			}
		}
	}
}