Function Calling with Small Language Models
In our previous article on running Phi-4 locally, we built a web-enhanced assistant that could search the internet and provide informed answers. Here's what that implementation looked like: def web_enhanced_query(question): # 1. ALWAYS search (hardcoded decision) search_results = search_web(question) # 2. Inject results into prompt prompt = f"""Here are recent search results: {search_results} Question: {question} Using only the information above, give a clear answer.""" # 3. Model just summarizes what it reads return ask_phi4(endpoint, model_id, prompt) Today, we're upgrading to true function calling. With this, we have ability to transform small language models from passive text generators into intelligent agents that can: Decide when to use external tools Reason which tool bests fit each task Execute real-world actions thrugh apis Function calling represents a significant evolution in AI capabilities. Let's understand where this positions our small language models: Agent Classification Framework Simple Reflex Agents (Basic) React to immediate input with predefined rules Example: Thermostat, basic chatbot Without function calling, models operate here Model-Based Agents (Intermediate) Maintain internal state and context Example: Robot vacuum with room mapping Function calling enables this level Goal-Based Agents (Advanced) Plan multi-step sequences to achieve objectives Example: Route planner, task scheduler Function calling + reasoning enables this Learning Agents (Expert) Adapt and improve over time Example: Recommendation systems Future: Function calling + fine-tuning As usual with these articles, let's get ready to get our hands dirty! Project Setup Let's set up our environment for building function-calling assistants. Prerequisites First, ensure you have Foundry Local installed and a model running. We'll use Qwen 2.5-7B for this tutorial as it has excellent function calling support. Important: Not all small language models support function calling equally. Qwen 2.5 was specifically trained for this capability and provides a reliable experience through Foundry Local. # 1. Check Foundry Local is installed foundry --version # 2. Start the Foundry Local service foundry service start # 3. Download and run Qwen 2.5-7B foundry model run qwen2.5-7b Python Environment Setup # 1. Create Python virtual environment python -m venv venv source venv/bin/activate # Windows: venv\Scripts\activate # 2. Install dependencies pip install openai requests python-dotenv # 3. Get a free OpenWeatherMap API key # Sign up at: https://openweathermap.org/api ``` Create `.env` file: ``` OPENWEATHER_API_KEY=your_api_key_here ``` Building a Weather-Aware Assistant So in this scenario, a user wants to plan outdoor activities but needs weather context. Without function calling, You will get something like this: User: "Should I schedule my team lunch outside at 2pm in Birmingham?" Model: "That depends on weather conditions. Please check the forecast for rain and temperature." However, with fucntion-calling you get an answer that is able to look up the weather and reply with the needed context. We will do that now. Understanding Foundry Local's Function Calling Implementation Before we start coding, there's an important implementation detail to understand. Foundry Local uses a non-standard function calling format. Instead of returning function calls in the standard OpenAI tool_calls field, Qwen models return the function call as JSON text in the response content. For example, when you ask about weather, instead of: # Standard OpenAI format message.tool_calls = [ {"name": "get_weather", "arguments": {"location": "Birmingham"}} ] You get: # Foundry Local format message.content = '{"name": "get_weather", "arguments": {"location": "Birmingham"}}' This means we need to parse the JSON from the content ourselves. Don't worry—this is straightforward, and I'll show you exactly how to handle it! Step 1: Define the Weather Tool Create weather_assistant.py: import os from openai import OpenAI import requests import json import re from dotenv import load_dotenv load_dotenv() # Initialize Foundry Local client client = OpenAI( base_url="http://127.0.0.1:59752/v1/", api_key="not-needed" ) # Define weather tool tools = [ { "type": "function", "function": { "name": "get_weather", "description": "Get current weather information for a location", "parameters": { "type": "object", "properties": { "location": { "type": "string", "description": "The city or location name" }, "units": { "type": "string", "description": "Temperature units", "enum": ["celsius", "fahrenheit"], "default": "celsius" } }, "required": ["location"] } } } ] A tool is necessary because it provides the model with a structured specification of what external functions are available and how to use them. The tool definition contains the function name, description, parameters schema, and information returned. Step 2: Implement the Weather Function def get_weather(location: str, units: str = "celsius") -> dict: """Fetch weather data from OpenWeatherMap API""" api_key = os.getenv("OPENWEATHER_API_KEY") url = "http://api.openweathermap.org/data/2.5/weather" params = { "q": location, "appid": api_key, "units": "metric" if units == "celsius" else "imperial" } response = requests.get(url, params=params, timeout=5) response.raise_for_status() data = response.json() temp_unit = "°C" if units == "celsius" else "°F" return { "location": data["name"], "temperature": f"{round(data['main']['temp'])}{temp_unit}", "feels_like": f"{round(data['main']['feels_like'])}{temp_unit}", "conditions": data["weather"][0]["description"], "humidity": f"{data['main']['humidity']}%", "wind_speed": f"{round(data['wind']['speed'] * 3.6)} km/h" } The model calls this function to get the weather data. it contacts OpenWeatherMap API, gets real weather data and returns it as a python dictionary Step 3: Parse Function Calls from Content This is the crucial step where we handle Foundry Local's non-standard format: def parse_function_call(content: str): """Extract function call JSON from model response""" if not content: return None json_pattern = r'\{"name":\s*"get_weather",\s*"arguments":\s*\{[^}]+\}\}' match = re.search(json_pattern, content) if match: try: return json.loads(match.group()) except json.JSONDecodeError: pass try: parsed = json.loads(content.strip()) if isinstance(parsed, dict) and "name" in parsed: return parsed except json.JSONDecodeError: pass return None Step 4: Main Chat Function with Function Calling and lastly, calling the model. Notice the tools and tool_choice parameter. Tools tells the model it is allowed to output a tool_call requesting that the function be executed. While tool_choice instructs the model how to decide whether to call a tool. def chat(user_message: str) -> str: """Process user message with function calling support""" messages = [ {"role": "user", "content": user_message} ] response = client.chat.completions.create( model="qwen2.5-7b-instruct-generic-cpu:4", messages=messages, tools=tools, tool_choice="auto", temperature=0.3, max_tokens=500 ) message = response.choices[0].message if message.content: function_call = parse_function_call(message.content) if function_call and function_call.get("name") == "get_weather": print(f"\n[Function Call] {function_call.get('name')}({function_call.get('arguments')})") args = function_call.get("arguments", {}) weather_data = get_weather(**args) print(f"[Result] {weather_data}\n") final_prompt = f"""User asked: "{user_message}" Weather data: {json.dumps(weather_data, indent=2)} Provide a natural response based on this weather information.""" final_response = client.chat.completions.create( model="qwen2.5-7b-instruct-generic-cpu:4", messages=[{"role": "user", "content": final_prompt}], max_tokens=200, temperature=0.7 ) return final_response.choices[0].message.content return message.content Step 5: Run the script Now put all the above together and run the script def main(): """Interactive weather assistant""" print("\nWeather Assistant") print("=" * 50) print("Ask about weather or general questions.") print("Type 'exit' to quit\n") while True: user_input = input("You: ").strip() if user_input.lower() in ['exit', 'quit']: print("\nGoodbye!") break if user_input: response = chat(user_input) print(f"Assistant: {response}\n") if __name__ == "__main__": if not os.getenv("OPENWEATHER_API_KEY"): print("Error: OPENWEATHER_API_KEY not set") print("Set it with: export OPENWEATHER_API_KEY='your_key_here'") exit(1) main() Note: Make sure Qwen 2.5 is running in Foundry Local in a new terminal Now let's talk about Model Context Protocol! Our weather assistant works beautifully with a single function, but what happens when you need dozens of tools? Database queries, file operations, calendar integration, email—each would require similar setup code. This is where Model Context Protocol (MCP) comes in. MCP is an open standard that provides pre-built, standardized servers for common tools. Instead of writing custom integration code for every capability, you can connect to MCP servers that handle the complexity for you. With MCP, You only need one command to enable weather, database, and file access npx @modelcontextprotocol/server-weather npx @modelcontextprotocol/server-sqlite npx @modelcontextprotocol/server-filesystem Your model automatically discovers and uses these tools without custom integration code. Learn more: Model Context Protocol Documentation EdgeAI Course - Module 03: MCP Integration Key Takeaways Function calling transforms models into agents - From passive text generators to active problem-solvers Qwen 2.5 has excellent function calling support - Specifically trained for reliable tool use Foundry Local uses non-standard format - Parse JSON from content instead of tool_calls field Start simple, then scale with MCP - Build one tool to understand the pattern, then leverage standards Documentation Running Phi-4 Locally with Foundry Local Phi-4: Small Language Models That Pack a Punch Microsoft Foundry Local GitHub EdgeAI for Beginners Course OpenWeatherMap API Documentation Model Context Protocol Qwen 2.5 Documentation Thank you for reading! I hope this article helps you build more capable AI agents with small language models. Function calling opens up incredible possibilities—from simple weather assistants to complex multi-tool workflows. Start with one tool, understand the pattern, and scale from there.PrivyDoc: Building a Zero-Data-Leak AI with Foundry Local & Microsoft's Agent Framework
Tired of choosing between powerful AI insights and sacrificing your data's privacy? PrivyDoc offers a groundbreaking solution. In this article, Microsoft MVP in AI, Shivam Goyal, introduces his innovative project that brings robust AI document analysis directly to your local machine, ensuring zero data ever leaves your device. Discover how PrivyDoc leverages two cutting-edge Microsoft technologies: Foundry Local: The secret sauce for 100% on-device AI processing, allowing advanced models to run securely without cloud dependency. Microsoft Agent Framework: The intelligent orchestrator that builds a sophisticated multi-agent pipeline, handling everything from text extraction and entity recognition to summarization and sentiment analysis. Learn about PrivyDoc's intuitive web UI, its multi-format support, and crucial features that make it perfect for sensitive industries like legal, healthcare, and finance. Say goodbye to privacy concerns and hello to AI-powered document intelligence without compromise.Edge AI for Beginners : Getting Started with Foundry Local
In Module 08 of the EdgeAI for Beginners course, Microsoft introduces Foundry Local a toolkit that helps you deploy and test Small Language Models (SLMs) completely offline. In this blog, I’ll share how I installed Foundry Local, ran the Phi-3.5-mini model on my windows laptop, and what I learned through the process. What Is Foundry Local? Foundry Local allows developers to run AI models locally on their own hardware. It supports text generation, summarization, and code completion — all without sending data to the cloud. Unlike cloud-based systems, everything happens on your computer, so your data never leaves your device. Prerequisites Before starting, make sure you have: Windows 10 or 11 Python 3.10 or newer Git Internet connection (for the first-time model download) Foundry Local installed Step 1 — Verify Installation After installing Foundry Local, open Command Prompt and type: foundry --version If you see a version number, Foundry Local is installed correctly. Step 2 — Start the Service Start the Foundry Local service using: foundry service start You should see a confirmation message that the service is running. Step 3 — List Available Models To view the models supported by your system, run: foundry model list You’ll get a list of locally available SLMs. Here’s what I saw on my machine: Note: Model availability depends on your device’s hardware. For most laptops, phi-3.5-mini works smoothly on CPU. Step 4 — Run the Phi-3.5 Model Now let’s start chatting with the model: foundry model run phi-3.5-mini-instruct-generic-cpu:1 Once it loads, you’ll enter an interactive chat mode. Try a simple prompt: Hello! What can you do? The model replies instantly — right from your laptop, no cloud needed. To exit, type: /exit How It Works Foundry Local loads the model weights from your device and performs inference locally.This means text generation happens using your CPU (or GPU, if available). The result: complete privacy, no internet dependency, and instant responses. Benefits for Students For students beginning their journey in AI, Foundry Local offers several key advantages: No need for high-end GPUs or expensive cloud subscriptions. Easy setup for experimenting with multiple models. Perfect for class assignments, AI workshops, and offline learning sessions. Promotes a deeper understanding of model behavior by allowing step-by-step local interaction. These factors make Foundry Local a practical choice for learning environments, especially in universities and research institutions where accessibility and affordability are important. Why Use Foundry Local Running models locally offers several practical benefits compared to using AI Foundry in the cloud. With Foundry Local, you do not need an internet connection, and all computations happen on your personal machine. This makes it faster for small models and more private since your data never leaves your device. In contrast, AI Foundry runs entirely on the cloud, requiring internet access and charging based on usage. For students and developers, Foundry Local is ideal for quick experiments, offline testing, and understanding how models behave in real-time. On the other hand, AI Foundry is better suited for large-scale or production-level scenarios where models need to be deployed at scale. In summary, Foundry Local provides a flexible and affordable environment for hands-on learning, especially when working with smaller models such as Phi-3, Qwen2.5, or TinyLlama. It allows you to experiment freely, learn efficiently, and better understand the fundamentals of Edge AI development. Optional: Restart Later Next time you open your laptop, you don’t have to reinstall anything. Just run these two commands again: foundry service start foundry model run phi-3.5-mini-instruct-generic-cpu:1 What I Learned Following the EdgeAI for Beginners Study Guide helped me understand: How edge AI applications work How small models like Phi 3.5 can run on a local machine How to test prompts and build chat apps with zero cloud usage Conclusion Running the Phi-3.5-mini model locally with Foundry Localgave me hands-on insight into edge AI. It’s an easy, private, and cost-free way to explore generative AI development. If you’re new to Edge AI, start with the EdgeAI for Beginners course and follow its Study Guide to get comfortable with local inference and small language models. Resources: EdgeAI for Beginners GitHub Repo Foundry Local Official Site Phi Model LinkEdge AI for Student Developers: Learn to Run AI Locally
AI isn’t just for the cloud anymore. With the rise of Small Language Models (SLMs) and powerful local inference tools, developers can now run intelligent applications directly on laptops, phones, and edge devices—no internet required. If you're a student developer curious about building AI that works offline, privately, and fast, Microsoft’s Edge AI for Beginners course is your perfect starting point. What Is Edge AI? Edge AI refers to running AI models directly on local hardware—like your laptop, mobile device, or embedded system—without relying on cloud servers. This approach offers: ⚡ Real-time performance 🔒 Enhanced privacy (no data leaves your device) 🌐 Offline functionality 💸 Reduced cloud costs Whether you're building a chatbot that works without Wi-Fi or optimizing AI for low-power devices, Edge AI is the future of intelligent, responsive apps. About the Course Edge AI for Beginners is a free, open-source curriculum designed to help you: Understand the fundamentals of Edge AI and local inference Explore Small Language Models like Phi-2, Mistral-7B, and Gemma Deploy models using tools like Llama.cpp, Olive, MLX, and OpenVINO Build cross-platform apps that run AI locally on Windows, macOS, Linux, and mobile The course is hosted on GitHub and includes hands-on labs, quizzes, and real-world examples. You can fork it, remix it, and contribute to the community. What You’ll Learn Module Focus 01. Introduction What is Edge AI and why it matters 02. SLMs Overview of small language models 03. Deployment Running models locally with various tools 04. Optimization Speeding up inference and reducing memory 05. Applications Building real-world Edge AI apps Each module is beginner-friendly and includes practical exercises to help you build and deploy your own local AI solutions. Who Should Join? Student developers curious about AI beyond the cloud Hackathon participants looking to build offline-capable apps Makers and builders interested in privacy-first AI Anyone who wants to explore the future of on-device intelligence No prior AI experience required just a willingness to learn and experiment. Why It Matters Edge AI is a game-changer for developers. It enables smarter, faster, and more private applications that work anywhere. By learning how to deploy AI locally, you’ll gain skills that are increasingly in demand across industries—from healthcare to robotics to consumer tech. Plus, the course is: 💯 Free and open-source 🧠 Backed by Microsoft’s best practices 🧪 Hands-on and project-based 🌐 Continuously updated Ready to Start? Head to aka.ms/edgeai-for-beginners and dive into the modules. Whether you're coding in your dorm room or presenting at your next hackathon, this course will help you build smarter AI apps that run right where you need them on the edge.
