OpenAI Agent

OpenAI API that supports function calling, it’s never been easier to build your own agent!

In this notebook tutorial, we showcase how to write your own OpenAI agent

Setup

First, you need to install the llamaindex package. You can do this by running the following command in your terminal:

pnpm i llamaindex

Then we can define a function to sum two numbers and another function to divide two numbers.

function sumNumbers({ a, b }: { a: number; b: number }): number {
  return a + b;
}

// Define a function to divide two numbers
function divideNumbers({ a, b }: { a: number; b: number }): number {
  return a / b;
}

Create a function tool

Now we can create a function tool from the sum function and another function tool from the divide function.

For the parameters of the sum function, we can define a JSON schema.

JSON Schema

const sumJSON = {
  type: "object",
  properties: {
    a: {
      type: "number",
      description: "The first number",
    },
    b: {
      type: "number",
      description: "The second number",
    },
  },
  required: ["a", "b"],
};

const divideJSON = {
  type: "object",
  properties: {
    a: {
      type: "number",
      description: "The dividend a to divide",
    },
    b: {
      type: "number",
      description: "The divisor b to divide by",
    },
  },
  required: ["a", "b"],
};

const sumFunctionTool = new FunctionTool(sumNumbers, {
  name: "sumNumbers",
  description: "Use this function to sum two numbers",
  parameters: sumJSON,
});

const divideFunctionTool = new FunctionTool(divideNumbers, {
  name: "divideNumbers",
  description: "Use this function to divide two numbers",
  parameters: divideJSON,
});

Create an OpenAIAgent

Now we can create an OpenAIAgent with the function tools.

const agent = new OpenAIAgent({
  tools: [sumFunctionTool, divideFunctionTool],
});

Chat with the agent

Now we can chat with the agent.

const response = await agent.chat({
  message: "How much is 5 + 5? then divide by 2",
});

console.log(String(response));

Full code

import { FunctionTool, OpenAIAgent } from "llamaindex";

// Define a function to sum two numbers
function sumNumbers({ a, b }: { a: number; b: number }): number {
  return a + b;
}

// Define a function to divide two numbers
function divideNumbers({ a, b }: { a: number; b: number }): number {
  return a / b;
}

// Define the parameters of the sum function as a JSON schema
const sumJSON = {
  type: "object",
  properties: {
    a: {
      type: "number",
      description: "The first number",
    },
    b: {
      type: "number",
      description: "The second number",
    },
  },
  required: ["a", "b"],
};

// Define the parameters of the divide function as a JSON schema
const divideJSON = {
  type: "object",
  properties: {
    a: {
      type: "number",
      description: "The argument a to divide",
    },
    b: {
      type: "number",
      description: "The argument b to divide",
    },
  },
  required: ["a", "b"],
};

async function main() {
  // Create a function tool from the sum function
  const sumFunctionTool = new FunctionTool(sumNumbers, {
    name: "sumNumbers",
    description: "Use this function to sum two numbers",
    parameters: sumJSON,
  });

  // Create a function tool from the divide function
  const divideFunctionTool = new FunctionTool(divideNumbers, {
    name: "divideNumbers",
    description: "Use this function to divide two numbers",
    parameters: divideJSON,
  });

  // Create an OpenAIAgent with the function tools
  const agent = new OpenAIAgent({
    tools: [sumFunctionTool, divideFunctionTool],
  });

  // Chat with the agent
  const response = await agent.chat({
    message: "How much is 5 + 5? then divide by 2",
  });

  // Print the response
  console.log(String(response));
}

main().then(() => {
  console.log("Done");
});