01 · Hello Agent

What this lesson demonstrates

This is the Agent primitive stripped to its essence. You build an agent from instructions plus a model, call it with a message, and it returns a response. That single loop is what everything later — tools, memory, workflows — builds on. The lesson runs the same call two ways: once collected all at once, once streamed token-by-token.

The code

Construction is factored out of main so the offline test can rebuild the identical agent with a fake credential:

func newJoker(endpoint, model string, cred azcore.TokenCredential) *agent.Agent {
    return foundryprovider.NewAgent(
        endpoint,
        cred,
        foundryprovider.ModelDeployment(model),
        foundryprovider.AgentConfig{
            Instructions: "You are good at telling jokes.",
            Config:       agent.Config{Name: "Joker"},
        },
    )
}

Then main runs it two ways off the same method:

resp, err := a.RunText(ctx, "Tell me a joke about a pirate.").Collect()

for update, err := range a.RunText(ctx, "Now tell one about a robot.", agent.Stream(true)) {
    demo.Print(update, err)
}

What to notice

• Two call styles, one method. RunText returns a ResponseStream. Call .Collect() to drain it into a finished *Response, or range over it with agent.Stream(true) to consume *ResponseUpdates as they arrive. Both types implement fmt.Stringer, so one demo.Print handles both.
• Streaming is a Go iterator, not a channel. The for update, err := range a.RunText(...) loop is a Go 1.23+ range-over-function iterator (iter.Seq2). There are no channels to close and no goroutines to manage — the gotcha here is that you don’t need the machinery you might expect.
• Construction is separated from main. newJoker(...) exists purely so the test can build the same agent offline and assert a.Name() == "Joker" without a network.

How it maps to Azure AI Foundry

foundryprovider.NewAgent binds the agent to your Foundry project’s Responses API, keyed by the model deployment name via ModelDeployment(model). Under the hood each RunText becomes a POST /responses with a bearer token from your Azure credential. The AgentConfig.Instructions field is the system prompt; agent.Config.Name is how the agent identifies itself.

Run it

go run ./tutorial/01-get-started/01_hello_agent

Expected: two jokes — the first collected, the second streamed. The offline structural test runs anywhere; the live model call is a second test gated behind AF_LIVE=1 (needs az login).

Next: 02 · Add Tools