Autonomous AI Agents with Google's Agent Development Kit (ADK)

# Step 1: Install Google ADK
pip install google-adk google-genai

# Step 2: Set your Google AI Studio API Key
import os
os.environ["GEMINI_API_KEY"] = "YOUR_API_KEY_HERE"

from google.adk import Agent
from google.adk.runners import Runner
from google.adk.sessions import InMemorySessionService
from google.genai import types

# 1. Define the agent (The Brain)
assistant_agent = Agent(
    name="research_assistant",
    instruction="A research assistant that helps answer questions with reasoning.",
    model="gemini-2.5-pro" # Note: older 1.5 models are deprecated!
)

# 2. Setup Session Service (The Memory Drawer)
session_service = InMemorySessionService()

# 3. Explicitly create the session first (Must await the coroutine)
await session_service.create_session(
    app_name="research_app",
    user_id="user_01",
    session_id="session_01"
)

# 4. Instantiate the base Runner, linking our custom session service
runner = Runner(
    app_name="research_app", 
    agent=assistant_agent, 
    session_service=session_service
)

# 5. Run the query through the runner!
query = "Explain quantum entanglement in simple terms, using an analogy."
user_message = types.Content(role="user", parts=[types.Part(text=query)])

event_stream = runner.run(
    user_id="user_01",
    session_id="session_01",
    new_message=user_message
)

# 6. Stream the text output cleanly
for event in event_stream:
    if event.content and event.content.parts:
        for part in event.content.parts:
            if part.text:
                print(part.text, end="")

from google.adk.tools import FunctionTool

# Step 1: Define the calculator tool function
def calculator(operation: str, num1: float, num2: float) -> str:
    """
    Perform basic arithmetic operations.
    
    Args:
        operation: One of 'add', 'subtract', 'multiply', 'divide'
        num1: First number
        num2: Second number
    
    Returns:
        Result of the calculation
    """
    operations = {
        'add': lambda a, b: a + b,
        'subtract': lambda a, b: a - b,
        'multiply': lambda a, b: a * b,
        'divide': lambda a, b: a / b if b != 0 else "Error: Division by zero"
    }
    
    result = operations.get(operation, lambda a, b: "Invalid operation")(num1, num2)
    return f"{num1} {operation} {num2} = {result}"

# Step 2: Pass the tool into the Agent configuration
agent_with_math = Agent(
    name="math_assistant",
    model="gemini-2.5-pro",
    instruction="Use the calculator tool for math operations.",
    tools=[
        FunctionTool(calculator)
    ]
)

import requests

def get_live_weather(city: str) -> str:
    """
    Get the current live weather for a given city.
    
    Args:
        city: The name of the city (e.g., 'Tokyo', 'Hyderabad')
    """
    try:
        # 1. Convert city name to latitude/longitude
        geo_url = f"https://geocoding-api.open-meteo.com/v1/search?name={city}&count=1&language=en&format=json"
        geo_response = requests.get(geo_url).json()
        
        if not geo_response.get("results"):
            return f"Could not find coordinates for city: {city}"
        
        lat = geo_response["results"][0]["latitude"]
        lon = geo_response["results"][0]["longitude"]
        
        # 2. Fetch the live weather using the coordinates
        weather_url = f"https://api.open-meteo.com/v1/forecast?latitude={lat}&longitude={lon}¤t=temperature_2m&temperature_unit=celsius"
        weather_response = requests.get(weather_url).json()
        
        current_temp = weather_response.get("current", {}).get("temperature_2m")
        return f"The current live temperature in {city} is {current_temp}°C."
        
    except Exception as e:
        return f"Error fetching weather data: {str(e)}"