Azure AI Agents function calling

Azure AI Agents supports function calling, which allows you to describe the structure of functions to an Assistant and then return the functions that need to be called along with their arguments.

Note

Runs expire ten minutes after creation. Be sure to submit your tool outputs before the expiration.

Supported models

The models page contains the most up-to-date information on regions/models where Agents are supported.

To use all features of function calling including parallel functions, you need to use a model that was released after November 6, 2023.

Define a function for your agent to call

Start by defining a function for your agent to call. When you create a function for an agent to call, you describe its structure of it with any required parameters in a docstring. Include all your function definitions in a single file, user_functions.py which you can then import into your main script.

import json
import datetime
from typing import Any, Callable, Set, Dict, List, Optional

def fetch_weather(location: str) -> str:
    """
    Fetches the weather information for the specified location.

    :param location (str): The location to fetch weather for.
    :return: Weather information as a JSON string.
    :rtype: str
    """
    # In a real-world scenario, you'd integrate with a weather API.
    # Here, we'll mock the response.
    mock_weather_data = {"New York": "Sunny, 25°C", "London": "Cloudy, 18°C", "Tokyo": "Rainy, 22°C"}
    weather = mock_weather_data.get(location, "Weather data not available for this location.")
    weather_json = json.dumps({"weather": weather})
    return weather_json

    # Statically defined user functions for fast reference
user_functions: Set[Callable[..., Any]] = {
    fetch_weather,
}

See the python file on GitHub for an example of a full series of function definitions. This file is referred to as user_functions.py in the following example below.

Create a client

In the sample below we create a client and define a toolset which will be used to process the functions defined in user_functions.

toolset: When using the toolset parameter, you provide not only the function definitions and descriptions but also their implementations. The SDK will execute these functions within create_and_run_process or streaming. These functions will be invoked based on their definitions.

import os
from azure.ai.projects import AIProjectClient
from azure.identity import DefaultAzureCredential
from azure.ai.projects.models import FunctionTool, ToolSet
from user_functions import user_functions # user functions which can be found in a user_functions.py file.

# Create an Azure AI Client from a connection string, copied from your Azure AI Foundry project.
# It should be in the format "<HostName>;<AzureSubscriptionId>;<ResourceGroup>;<HubName>"
# Customers need to login to Azure subscription via Azure CLI and set the environment variables

project_client = AIProjectClient.from_connection_string(
    credential=DefaultAzureCredential(),
    conn_str=os.environ["PROJECT_CONNECTION_STRING"],
)

# Initialize agent toolset with user functions
functions = FunctionTool(user_functions)
toolset = ToolSet()
toolset.add(functions)

Submitting function outputs


# Create agent with toolset and process a run

agent = project_client.agents.create_agent(
    model="gpt-4o-mini", name="my-agent", instructions="You are a helpful agent", toolset=toolset
)
print(f"Created agent, ID: {agent.id}")

Create a thread

# Create thread for communication
thread = project_client.agents.create_thread()
print(f"Created thread, ID: {thread.id}")

# Create message to thread
message = project_client.agents.create_message(
    thread_id=thread.id,
    role="user",
    content="Hello, send an email with the datetime and weather information in New York?",
)
print(f"Created message, ID: {message.id}")

Create a run and check the output

# Create and process agent run in thread with tools
run = project_client.agents.create_and_process_run(thread_id=thread.id, assistant_id=agent.id)
print(f"Run finished with status: {run.status}")

if run.status == "failed":
    print(f"Run failed: {run.last_error}")

# Delete the agent when done
project_client.agents.delete_agent(agent.id)
print("Deleted agent")

# Fetch and log all messages
messages = project_client.agents.list_messages(thread_id=thread.id)
print(f"Messages: {messages}")

See also