3. Build Your First Agent

Hello World Agent

Let's build a simple agent that greets users and remembers their name.

JavaScript / TypeScript

import { Agent, AgentClient } from "@microsoft/agents";
import { DefaultAzureCredential } from "@azure/identity";

const agent = new Agent({
  name: "GreeterAgent",
  instructions: "You are a friendly greeter. Greet the user warmly and remember their name.",
  model: "gpt-4o",
  auth: new DefaultAzureCredential(),
});

const client = new AgentClient(agent);
const response = await client.sendMessage("Hi, I'm Snehal!");
console.log(response.text);

Agent Configuration

Prompt Design Best Practices

• Be specific about the agent's role and boundaries
• Include examples of expected interactions (few-shot)
• Define what the agent should not do
• Keep instructions concise but comprehensive

Agent Lifecycle

An agent progresses through these states:

1. Created — definition saved
2. Configured — memory, tools, and guardrails attached
3. Active — ready to receive messages
4. Processing — handling a conversation turn
5. Idle — waiting for next input