How to build Tool-calling Agents with Azure OpenAI and Lang Graph
Introducing MyTreat Our demo is a fictional website that shows customers their total bill in dollars, but they have the option of getting the total bill in their local currencies. The button sends a request to the Node.js service and a response is simply returned from our Agent given the tool it chooses. Let’s dive in and understand how this works from a broader perspective. Prerequisites An active Azure subscription. You can sign up for a free trial here or get $100 worth of credits on Azure every year if you are a student. A GitHub account (not necessarily) Node.js LTS 18 + VS Code installed (or your favorite IDE) Basic knowledge of HTML, CSS, JS Creating an Azure OpenAI Resource Go over to your browser and key in portal.azure.com to access the Microsoft Azure Portal. Over there navigate to the search bar and type Azure OpenAI. Go ahead and click on + Create. Fill in the input boxes with appropriate, for example, as shown below then press on next until you reach review and submit then finally click on Create. After the deployment is done, go to the deployment and access Azure AI Foundry portal using the button as show below. You can also use the link as demonstrated below. In the Azure AI Foundry portal, we have to create our model instance so we have to go over to Model Catalog on the left panel beneath Get Started. Select a desired model, in this case I used gpt-35-turbo for chat completion (in your case use gpt-4o). Below is a way of doing this. Choose a model (gpt-4o) Click on deploy Give the deployment a new name e.g. myTreatmodel, then click deploy and wait for it to finish On the left panel go over to deployments and you will see the model you have created. Access your Azure OpenAI Resource Key Go back to Azure portal and specifically to the deployment instance that we have and select on the left panel, Resource Management. Click on Keys and Endpoints. Copy any of the keys as shown below and keep it very safe as we will use it in our .env file. Configuring your project Create a new project folder on your local machine and add these variables to the .env file in the root folder. AZURE_OPENAI_API_INSTANCE_NAME= AZURE_OPENAI_API_DEPLOYMENT_NAME= AZURE_OPENAI_API_KEY= AZURE_OPENAI_API_VERSION="2024-08-01-preview" LANGCHAIN_TRACING_V2="false" LANGCHAIN_CALLBACKS_BACKGROUND = "false" PORT=4556 Starting a new project Go over to https://github.com/tiprock-network/mytreat.git and follow the instructions to setup the new project, if you do not have git installed, go over to the Code button and press Download ZIP. This will enable you get the project folder and follow the same procedure for setting up. Creating a custom tool In the utils folder the math tool was created, this code show below uses tool from Langchain to build a tool and the schema of the tool is created using zod.js, a library that helps in validating an object’s property value. The price function takes in an array of prices and the exchange rate, adds the prices up and converts them using the exchange rate as shown below. import { tool } from '@langchain/core/tools' import { z } from 'zod' const priceConv = tool((input) =>{ //get the prices and add them up after turning each into let sum = 0 input.prices.forEach((price) => { let price_check = parseFloat(price) sum += price_check }) //now change the price using exchange rate let final_price = parseFloat(input.exchange_rate) * sum //return return final_price },{ name: 'add_prices_and_convert', description: 'Add prices and convert based on exchange rate.', schema: z.object({ prices: z.number({ required_error: 'Price should not be empty.', invalid_type_error: 'Price must be a number.' }).array().nonempty().describe('Prices of items listed.'), exchange_rate: z.string().describe('Current currency exchange rate.') }) }) export { priceConv } Utilizing the tool In the controller’s folder we then bring the tool in by importing it. After that we pass it in to our array of tools. Notice that we have the Tavily Search Tool, you can learn how to implement in the Additional Reads Section or just remove it. Agent Model and the Call Process This code defines an AI agent using LangGraph and LangChain.js, powered by GPT-4o from Azure OpenAI. It initializes a ToolNode to manage tools like priceConv and binds them to the agent model. The StateGraph handles decision-making, determining whether the agent should call a tool or return a direct response. If a tool is needed, the workflow routes the request accordingly; otherwise, the agent responds to the user. The callModel function invokes the agent, processing messages and ensuring seamless tool integration. The searchAgentController is a GET endpoint that accepts user queries (text_message). It processes input through the compiled LangGraph workflow, invoking the agent to generate a response. If a tool is required, the agent calls it before finalizing the output. The response is then sent back to the user, ensuring dynamic and efficient tool-assisted reasoning. //create tools the agent will use //const agentTools = [new TavilySearchResults({maxResults:5}), priceConv] const agentTools = [ priceConv] const toolNode = new ToolNode(agentTools) const agentModel = new AzureChatOpenAI({ model:'gpt-4o', temperature:0, azureOpenAIApiKey: AZURE_OPENAI_API_KEY, azureOpenAIApiInstanceName:AZURE_OPENAI_API_INSTANCE_NAME, azureOpenAIApiDeploymentName:AZURE_OPENAI_API_DEPLOYMENT_NAME, azureOpenAIApiVersion:AZURE_OPENAI_API_VERSION }).bindTools(agentTools) //make a decision to continue or not const shouldContinue = ( state ) => { const { messages } = state const lastMessage = messages[messages.length -1] //upon tool call we go to tools if("tool_calls" in lastMessage && Array.isArray(lastMessage.tool_calls) && lastMessage.tool_calls?.length) return "tools"; //if no tool call is made we stop and return back to the user return END } const callModel = async (state) => { const response = await agentModel.invoke(state.messages) return { messages: [response] } } //define a new graph const workflow = new StateGraph(MessagesAnnotation) .addNode("agent", callModel) .addNode("tools", toolNode) .addEdge(START, "agent") .addConditionalEdges("agent", shouldContinue, ["tools", END]) .addEdge("tools", "agent") const appAgent = workflow.compile() The above is implemented with the following code: Frontend The frontend is a simple HTML+CSS+JS stack that demonstrated how you can use an API to integrate this AI Agent to your website. It sends a GET request and uses the response to get back the right answer. Below is an illustration of how fetch API has been used. const searchAgentController = async ( req, res ) => { //get human text const { text_message } = req.query if(!text_message) return res.status(400).json({ message:'No text sent.' }) //invoke the agent const agentFinalState = await appAgent.invoke( { messages: [new HumanMessage(text_message)] }, {streamMode: 'values'} ) //const agentFinalState_b = await agentModel.invoke(text_message) /*return res.status(200).json({ answer:agentFinalState.messages[agentFinalState.messages.length - 1].content })*/ //console.log(agentFinalState_b.tool_calls) res.status(200).json({ text: agentFinalState.messages[agentFinalState.messages.length - 1].content }) } There you go! We have created a basic tool-calling agent using Azure and Langchain successfully, go ahead and expand the code base to your liking. If you have questions you can comment below or reach out on my socials. Additional Reads Azure Open AI Service Models Generative AI for Beginners AI Agents for Beginners Course Lang Graph Tutorial Develop Generative AI Apps in Azure AI Foundry PortalHow to use any Python AI agent framework with free GitHub Models
I ❤️ when companies offer free tiers for developer services, since it gives everyone a way to learn new technologies without breaking the bank. Free tiers are especially important for students and people between jobs, when the desire to learn is high but the available cash is low. That's why I'm such a fan of GitHub Models: free, high-quality generative AI models available to anyone with a GitHub account. The available models include the latest OpenAI LLMs (like o3-mini), LLMs from the research community (like Phi and Llama), LLMs from other popular providers (like Mistral and Jamba), multimodal models (like gpt-4o and llama-vision-instruct) and even a few embedding models (from OpenAI and Cohere). With access to such a range of models, you can prototype complex multi-model workflows to improve your productivity or heck, just make something fun for yourself. 🤗 To use GitHub Models, you can start off in no-code mode: open the playground for a model, send a few requests, tweak the parameters, and check out the answers. When you're ready to write code, select "Use this model". A screen will pop up where you can select a programming language (Python/JavaScript/C#/Java/REST) and select an SDK (which varies depending on model). Then you'll get instructions and code for that model, language, and SDK. But here's what's really cool about GitHub Models: you can use them with all the popular Python AI frameworks, even if the framework has no specific integration with GitHub Models. How is that possible? The vast majority of Python AI frameworks support the OpenAI Chat Completions API, since that API became a defacto standard supported by many LLM API providers besides OpenAI itself. GitHub Models also provide OpenAI-compatible endpoints for chat completion models. Therefore, any Python AI framework that supports OpenAI-like models can be used with GitHub Models as well. 🎉 To prove it, I've made a new repository with examples from eight different Python AI agent packages, all working with GitHub Models: python-ai-agent-frameworks-demos. There are examples for AutoGen, LangGraph, Llamaindex, OpenAI Agents SDK, OpenAI standard SDK, PydanticAI, Semantic Kernel, and SmolAgents. You can open that repository in GitHub Codespaces, install the packages, and get the examples running immediately. Now let's walk through the API connection code for GitHub Models for each framework. Even if I missed your favorite framework, I hope my tips here will help you connect any framework to GitHub Models. OpenAI I'll start with openai , the package that started it all! import openai client = openai.OpenAI( api_key=os.environ["GITHUB_TOKEN"], base_url="https://models.inference.ai.azure.com") The code above demonstrates the two key parameters we'll need to configure for all frameworks: api_key : When using OpenAI.com, you pass your OpenAI API key here. When using GitHub Models, you pass in a Personal Access Token (PAT). If you open the repository (or any repository) in GitHub Codespaces, a PAT is already stored in the GITHUB_TOKEN environment variable. However, if you're working locally with GitHub Models, you'll need to generate a PAT yourself and store it. PATs expire after a while, so you need to generate new PATs every so often. base_url : This parameter tells the OpenAI client to send all requests to "https://models.inference.ai.azure.com" instead of the OpenAI.com API servers. That's the domain that hosts the OpenAI-compatible endpoint for GitHub Models, so you'll always pass that domain as the base URL. If we're working with the new openai-agents SDK, we use very similar code, but we must use the AsyncOpenAI client from openai instead. Lately, Python AI packages are defaulting to async, because it's so much better for performance. import agents import openai client = openai.AsyncOpenAI( base_url="https://models.inference.ai.azure.com", api_key=os.environ["GITHUB_TOKEN"]) model = agents.OpenAIChatCompletionsModel( model="gpt-4o", openai_client=client) spanish_agent = agents.Agent( name="Spanish agent", instructions="You only speak Spanish.", model=model) PydanticAI Now let's look at all of the packages that make it really easy for us, by allowing us to directly bring in an instance of either OpenAI or AsyncOpenAI . For PydanticAI, we configure an AsyncOpenAI client, then construct an OpenAIModel object from PydanticAI, and pass that model to the agent: import openai import pydantic_ai import pydantic_ai.models.openai client = openai.AsyncOpenAI( api_key=os.environ["GITHUB_TOKEN"], base_url="https://models.inference.ai.azure.com") model = pydantic_ai.models.openai.OpenAIModel( "gpt-4o", provider=OpenAIProvider(openai_client=client)) spanish_agent = pydantic_ai.Agent( model, system_prompt="You only speak Spanish.") Semantic Kernel For Semantic Kernel, the code is very similar. We configure an AsyncOpenAI client, then construct an OpenAIChatCompletion object from Semantic Kernel, and add that object to the kernel. import openai import semantic_kernel.connectors.ai.open_ai import semantic_kernel.agents chat_client = openai.AsyncOpenAI( api_key=os.environ["GITHUB_TOKEN"], base_url="https://models.inference.ai.azure.com") chat = semantic_kernel.connectors.ai.open_ai.OpenAIChatCompletion( ai_model_id="gpt-4o", async_client=chat_client) kernel.add_service(chat) spanish_agent = semantic_kernel.agents.ChatCompletionAgent( kernel=kernel, name="Spanish agent" instructions="You only speak Spanish") AutoGen Next, we'll check out a few frameworks that have their own wrapper of the OpenAI clients, so we won't be using any classes from openai directly. For AutoGen, we configure both the OpenAI parameters and the model name in the same object, then pass that to each agent: import autogen_ext.models.openai import autogen_agentchat.agents client = autogen_ext.models.openai.OpenAIChatCompletionClient( model="gpt-4o", api_key=os.environ["GITHUB_TOKEN"], base_url="https://models.inference.ai.azure.com") spanish_agent = autogen_agentchat.agents.AssistantAgent( "spanish_agent", model_client=client, system_message="You only speak Spanish") LangGraph For LangGraph, we configure a very similar object, which even has the same parameter names: import langchain_openai import langgraph.graph model = langchain_openai.ChatOpenAI( model="gpt-4o", api_key=os.environ["GITHUB_TOKEN"], base_url="https://models.inference.ai.azure.com", ) def call_model(state): messages = state["messages"] response = model.invoke(messages) return {"messages": [response]} workflow = langgraph.graph.StateGraph(MessagesState) workflow.add_node("agent", call_model) SmolAgents Once again, for SmolAgents, we configure a similar object, though with slightly different parameter names: import smolagents model = smolagents.OpenAIServerModel( model_id="gpt-4o", api_key=os.environ["GITHUB_TOKEN"], api_base="https://models.inference.ai.azure.com") agent = smolagents.CodeAgent(model=model) Llamaindex I saved Llamaindex for last, as it is the most different. The llama-index package has a different constructor for OpenAI.com versus OpenAI-like servers, so I opted to use that OpenAILike constructor instead. However, I also needed an embeddings model for my example, and the package doesn't have an OpenAIEmbeddingsLike constructor, so I used the standard OpenAIEmbedding constructor. import llama_index.embeddings.openai import llama_index.llms.openai_like import llama_index.core.agent.workflow Settings.llm = llama_index.llms.openai_like.OpenAILike( model="gpt-4o", api_key=os.environ["GITHUB_TOKEN"], api_base="https://models.inference.ai.azure.com", is_chat_model=True) Settings.embed_model = llama_index.embeddings.openai.OpenAIEmbedding( model="text-embedding-3-small", api_key=os.environ["GITHUB_TOKEN"], api_base="https://models.inference.ai.azure.com") agent = llama_index.core.agent.workflow.ReActAgent( tools=query_engine_tools, llm=Settings.llm) Choose your models wisely! In all of the examples above, I specified the gpt-4o model. The gpt-4o model is a great choice for agents because it supports function calling, and many agent frameworks only work (or work best) with models that natively support function calling. Fortunately, GitHub Models includes multiple models that support function calling, at least in my basic experiments: gpt-4o gpt-4o-mini o3-mini AI21-Jamba-1.5-Large AI21-Jamba-1.5-Mini Codestral-2501 Cohere-command-r Ministral-3B Mistral-Large-2411 Mistral-Nemo Mistral-small You might find that some models work better than others, especially if you're using agents with multiple tools. With GitHub Models, it's very easy to experiment and see for yourself, by simply changing the model name and re-running the code. Join the AI Agents Hackathon We are currently running a free virtual hackathon from April 8th - 30th, to challenge developers to create agentic applications using Microsoft technologies. You could build an agent entirely using GitHub Models and submit it to the hackathon for a chance to win amazing prizes! You can also join our 30+ streams about building AI agents, including a stream all about prototyping with GitHub Models. Learn more and register at https://aka.ms/agentshack
