hello

Hello World Example

The simplest SDK example - open a conversation and send a message.

What You'll Learn

• Opening a conversation from a pack file with sdk.Open()
• Setting template variables with SetVar()
• Sending messages with Send()
• Multi-turn conversation context

Prerequisites

• Go 1.26+
• An API key for one of: OpenAI, Anthropic, or Google

Running the Example

The pack does not name a provider — the SDK detects one from the environment, so any of these works:

export OPENAI_API_KEY=your-key       # uses gpt-4o
# or
export ANTHROPIC_API_KEY=your-key
# or
export GOOGLE_API_KEY=your-key

go run .

Code Overview

// Open a conversation from a pack file
conv, err := sdk.Open("./hello.pack.json", "chat")
if err != nil {
    log.Fatal(err)
}
defer conv.Close()

// Set template variables (substituted in system prompt)
conv.SetVar("user_name", "World")

// Send a message and get a response
ctx := context.Background()
resp, err := conv.Send(ctx, "Say hello!")
fmt.Println(resp.Text())

// Context is maintained across turns
resp, _ = conv.Send(ctx, "What's my name?")
fmt.Println(resp.Text())  // Remembers "World"

Pack File Structure

The hello.pack.json defines:

• Prompt: A friendly assistant with {{user_name}} template variable

It deliberately does not pin a provider, so the example runs against whichever of OpenAI / Anthropic / Google you have a key for.

{
  "prompts": {
    "chat": {
      "system_template": "You are a friendly assistant. The user's name is {{user_name}}."
    }
  }
}

Key Concepts

1. Pack-First Design - All configuration lives in the pack file
2. Template Variables - Use {{variable}} in prompts, set with SetVar()
3. Conversation Context - Messages are remembered across Send() calls
4. Resource Cleanup - Always defer conv.Close()

Next Steps

• Streaming Example - Real-time response streaming
• Tools Example - Function calling
• HITL Example - Human-in-the-loop approval