# Agent Observability and Evaluation with Galileo

[Galileo](https://app.galileo.ai/) is an AI evaluation and observability platform that delivers end-to-end tracing, evaluation, and monitoring for AI applications. Galileo supports direct OpenTelemetry (OTel) trace ingestion from ADK for agent runs, tool calls, and model requests.

For more information, see Galileo’s [Google ADK integration](https://v2docs.galileo.ai/sdk-api/third-party-integrations/opentelemetry-and-openinference/google-adk) docs.

## Prerequisites

- A [Galileo API key](https://v2docs.galileo.ai/references/faqs/find-keys#galileo-api-key)
- A Galileo Project and Log stream
- A [Gemini API Key](https://aistudio.google.com/app/apikey)

## Install dependencies

```bash
pip install google-adk openinference-instrumentation-google-adk python-dotenv galileo
```

Optionally, use the `requirements.txt` from the [completed example](https://github.com/rungalileo/sdk-examples/tree/main/python/agent/google-adk).

## Set environment variables

Configure environment variables:

my_agent/.env

```text
# Gemini environment variables
GOOGLE_GENAI_USE_ENTERPRISE=0
GOOGLE_API_KEY="YOUR_API_KEY"

# Galileo environment variables
GALILEO_API_KEY="YOUR_API_KEY"
GALILEO_PROJECT="YOUR_PROJECT"
GALILEO_LOG_STREAM="YOUR_LOG_STREAM"
```

## Configure OpenTelemetry (required)

You must configure an OTLP exporter and set a global tracer provider before using any ADK components so that spans are emitted to Galileo.

```python
# my_agent/agent.py

from dotenv import load_dotenv

load_dotenv()

# OpenTelemetry imports
from opentelemetry.sdk import trace as trace_sdk

# Galileo span processor (auto-configures OTLP headers & endpoint from env vars)
from galileo import otel

# OpenInference instrumentation for ADK
from openinference.instrumentation.google_adk import GoogleADKInstrumentor

# Create tracer provider and register Galileo span processor
tracer_provider = trace_sdk.TracerProvider()
galileo_span_processor = otel.GalileoSpanProcessor()
tracer_provider.add_span_processor(galileo_span_processor)

# Instrument Google ADK with OpenInference (this captures inputs/outputs)
GoogleADKInstrumentor().instrument(tracer_provider=tracer_provider)
```

## Example: Trace an ADK agent

Now you can add the agent code for a simple current time agent, after the code that sets up the OTLP exporter and tracer provider:

```python
# my_agent/agent.py

from google.adk.agents import Agent

def get_current_time(city: str) -> dict:
    """Returns the current time in a specified city."""
    return {"status": "success", "city": city, "time": "10:30 AM"}


root_agent = Agent(
    model="gemini-flash-latest",
    name="root_agent",
    description="Tells the current time in a specified city.",
    instruction=(
        "You are a helpful assistant that tells the current time in cities. "
        "Use the 'get_current_time' tool for this purpose."
    ),
    tools=[get_current_time],
)
```

Run the agent with:

```bash
adk run my_agent
```

And ask it a question:

```console
What time is it in London?
```

```console
[root_agent]: The current time in London is 10:30 AM.
```

See the full [Google ADK + OpenTelemetry Example Project](https://github.com/rungalileo/sdk-examples/tree/main/python/agent/google-adk) for a completed example.

## View traces in Galileo

Select your Project and inspect the traces and spans in your Log Stream.

## Resources

- [Galileo Google ADK Integration Documentation](https://v2docs.galileo.ai/sdk-api/third-party-integrations/opentelemetry-and-openinference/google-adk): Official documentation for integrating a Google ADK project with Galileo using OpenTelemetry and OpenInference.
- [Google ADK + OpenTelemetry Example Project](https://github.com/rungalileo/sdk-examples/tree/main/python/agent/google-adk): This is an example project demonstrating how to use Galileo with the Google ADK. This example is a completed [Google ADK Python Quickstart](https://adk.dev/get-started/python/index.md) with Galileo instrumented on top.