Tutorial: Basic Chat Application

This is the complete example implementation for the Basic Chat Application Tutorial. It demonstrates how to build a chat application using LangChainGo, progressing from a simple implementation to an advanced one with conversation memory and chains.

Prerequisites

• Go 1.21 or later
• OpenAI API key

Setup

Set your OpenAI API key as an environment variable:

export OPENAI_API_KEY="your-api-key-here"

Running the Examples

This example includes implementations of all steps from the tutorial:

Step 3: Basic Chat (One-shot)

Sends a single message to the LLM and prints the response.

go run . step3
# or
go run . basic

Step 4: Interactive Chat

Interactive chat session without memory (each message is independent).

go run . step4
# or
go run . interactive

Step 5: Chat with Memory

Interactive chat that remembers the conversation history.

go run . step5
# or
go run . memory

Step 6: Advanced Chat with Chains

Full-featured chat using chains with automatic memory management.

go run . step6
# or
go run . advanced
# or just run without arguments (default)
go run .

Features by Step

Step 3 - Basic Features:

• Simple LLM initialization
• Single prompt/response interaction
• Basic error handling

Step 4 - Interactive Features:

• Interactive input loop
• Graceful exit with 'quit' command
• Error handling for failed requests

Step 5 - Memory Features:

• Conversation buffer memory
• Context preservation across messages
• Manual prompt construction with history

Step 6 - Advanced Features:

• Conversation chains with built-in templates
• Automatic memory management
• Structured conversation flow
• Clean separation of concerns

Code Structure

• main.go - Complete implementation with all steps
• step3_basic.go - Basic chat implementation (build tag: example)
• step4_interactive.go - Interactive chat implementation (build tag: example)
• step5_memory.go - Chat with memory implementation (build tag: example)
• step6_advanced.go - Advanced chat with chains (build tag: example)

Tutorial Reference

This example implements the tutorial from: Building a Basic Chat Application

Customization

You can customize the behavior by modifying:

1. Prompt Template (Step 6): Edit the template string to change the AI's personality
2. Model Selection: Pass options to openai.New() to use different models
3. Memory Type: Replace memory.NewConversationBuffer() with other memory types
4. Error Handling: Add retry logic or custom error messages

Example Session

$ go run .
=== Step 6: Advanced Chat with Chains ===
Advanced Chat Application (type 'quit' to exit)
----------------------------------------
You: Hello! Who are you?
AI: Hello! I'm an AI assistant created to help answer questions and have conversations. I'm here to provide helpful, accurate, and friendly responses to whatever you'd like to discuss. How can I assist you today?

You: Can you remember what I just asked?
AI: Yes, I can remember our conversation! You just asked me "Hello! Who are you?" and I introduced myself as an AI assistant who is here to help answer questions and have conversations with you.

You: quit
Goodbye!