How to create your own AI agent using Javascript

 

You can create your own AI Agent in JavaScript (Node.js) using:

• OpenAI API
• Memory
• Tools/functions
• Chat interface

Create AI Agent

<script>

require("dotenv").config();

const express = require("express");

const cors = require("cors");

const OpenAI = require("openai");

const app = express();

app.use(cors());

app.use(express.json());

const client = new OpenAI({

  apiKey: process.env.OPENAI_API_KEY,

});

// Simple Tool

function calculator(a, b) {

  return a + b;

}

app.post("/chat", async (req, res) => {

  const userMessage = req.body.message;

  try {

    // Tool Logic

    if(userMessage.includes("add")) {

      const result = calculator(10, 20);

      return res.json({

        reply: "Answer is " + result

      });

    }

    // AI Response

    const response = await client.chat.completions.create({

      model: "gpt-4.1-mini",

      messages: [

        {

          role: "system",

          content: "You are a helpful AI agent."

        },

        {

          role: "user",

          content: userMessage

        }

      ]

    });

    res.json({

      reply: response.choices[0].message.content

    });

  } catch (error) {

    console.log(error);

    res.json({

      reply: "Error occurred"

    });

  }

});

app.listen(3000, () => {

  console.log("Server running on port 3000");

});

</script>

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