Galileo

Overview

This guide demonstrates how to integrate Galileo with CrewAI for comprehensive tracing and Evaluation Engineering. By the end of this guide, you will be able to trace your CrewAI agents, monitor their performance, and evaluate their behaviour with Galileo’s powerful observability platform.

What is Galileo? Galileo is AI evaluation and observability platform that delivers end-to-end tracing, evaluation, and monitoring for AI applications. It enables teams to capture ground truth, create robust guardrails, and run systematic experiments with built-in experiment tracking and performance analytics—ensuring reliability, transparency, and continuous improvement across the AI lifecycle.

Getting started

This tutorial follows the CrewAI quickstart and shows how to add Galileo’s CrewAIEventListener, an event handler. For more information, see Galileo’s Add Galileo to a CrewAI Application how-to guide.

Note This tutorial assumes you have completed the CrewAI quickstart. If you want a completed comprehensive example, see the Galileo CrewAI sdk-example repo.

Step 1: Install dependencies

Install the required dependencies for your app. Create a virtual environment using your preferred method, then install dependencies inside that environment using your preferred tool:

uv add galileo

Step 2: Add to the .env file from the CrewAI quickstart

# Your Galileo API key
GALILEO_API_KEY="your-galileo-api-key"

# Your Galileo project name
GALILEO_PROJECT="your-galileo-project-name"

# The name of the Log stream you want to use for logging
GALILEO_LOG_STREAM="your-galileo-log-stream "

Step 3: Add the Galileo event listener

To enable logging with Galileo, you need to create an instance of the CrewAIEventListener. Import the Galileo CrewAI handler package by adding the following code at the top of your main.py file:

from galileo.handlers.crewai.handler import CrewAIEventListener

At the start of your run function, create the event listener:

def run():
    # Create the event listener
    CrewAIEventListener()
    # The rest of your existing code goes here

When you create the listener instance, it is automatically registered with CrewAI.

Step 4: Run your crew

Run your crew with the CrewAI CLI:

crewai run

Step 5: View the traces in Galileo

Once your crew has finished, the traces will be flushed and appear in Galileo.

Understanding the Galileo Integration

Galileo integrates with CrewAI by registering an event listener that captures Crew execution events (e.g., agent actions, tool calls, model responses) and forwards them to Galileo for observability and evaluation.

Understanding the event listener

Creating a CrewAIEventListener() instance is all that’s required to enable Galileo for a CrewAI run. When instantiated, the listener:

• Automatically registers itself with CrewAI
• Reads Galileo configuration from environment variables
• Logs all run data to the Galileo project and log stream specified by GALILEO_PROJECT and GALILEO_LOG_STREAM

No additional configuration or code changes are required. All data from this run is logged to the Galileo project and log stream specified by your environment configuration (for example, GALILEO_PROJECT and GALILEO_LOG_STREAM).