PubNub Go Chat Application

A simple real-time chat application built with Go and PubNub that allows multiple clients to exchange messages instantly.

Resources

• PubNub Go SDK
• PubNub Go SDK documentation

Features

• ✅ Real-time messaging between multiple clients
• ✅ User presence notifications (join/leave events)
• ✅ Simple command-line interface
• ✅ Message timestamps
• ✅ Built entirely with Go and PubNub SDK

Prerequisites

• Go 1.21 or later
• PubNub account and Publish / Subscribe keys

Setup to build the sample

1. Clone the sample app

git clone https://github.com/PubNubDevelopers/pubnub-go-chat.git
cd pubnub-go-chat

2. Get PubNub Keys

1. Sign up for a free PubNub account at https://admin.pubnub.com
2. Create a new app in the PubNub Admin Portal
3. Enable Presence Events on the keyset
4. Copy the Publish and Subscribe keys from the app's keyset

3. Configure the Application

Edit the constants in main.go to define your PubNub keys. You don't need to change the CHAT_CHANNEL value.

const (
  PUBLISH_KEY   = "Change me: your-publish-key-here"
  SUBSCRIBE_KEY = "Change me: your-subscribe-key-here"
  CHAT_CHANNEL  = "chat-room"
)

4. Install Dependencies

go mod tidy

Running the Sample Application

To test the chat functionality between two clients, open two terminal windows:

Terminal 1:

go run main.go

Terminal 2:

go run main.go

Enter different usernames in each terminal and start chatting!

Usage

1. When you start the application, you'll be prompted to enter a username
2. Once connected, you can start typing messages
3. Messages from other users will appear in real-time
4. You'll see presence notifications when users join or leave the chat. This is powered by PubNub presence
5. Type quit or exit to leave the chat

Example Session

🚀 PubNub Go Chat Application
=============================
Enter your username: Alice
Welcome Alice! You're now entering the chat room.
Type 'quit' to exit the chat.
=============================
✅ Connected to PubNub! You can start chatting now.

🟢 Bob joined the chat
You: Hello everyone!

💬 [14:32:15] Bob: Hi Alice! How are you?
You: I'm doing great! How about you?

💬 [14:32:30] Bob: Fantastic! This chat app works perfectly.
You: quit
👋 Goodbye!

Architecture / PubNub Features Used

The application uses the following PubNub features:

• Publish/Subscribe: Core messaging functionality
• Presence: Tracks when users join/leave the chat
• Real-time Events: Handles incoming messages and status updates through PubNub channels

Key Components

• PubNub Configuration: Sets up the client with your API keys
• Event Listener: Handles incoming messages, presence events, and connection status
• Message Publishing: Sends chat messages to the PubNub channel
• Presence Monitoring: Shows when users join or leave the chat room

Customization

You can customize the application by:

• Changing the CHAT_CHANNEL constant to use different chat rooms
• Modifying the ChatMessage struct to include additional fields
• Adding command parsing for special chat commands (similar to how the current app handles quit and exit)
• Add support for message history

Troubleshooting

Connection Issues

• Verify your internet connection
• Check that your PubNub keys are correct
• Ensure you're not behind a firewall blocking PubNub connections

Presence Messages not showing

• Check you have presence enabled on your keyset
• Check presence is enabled on your channel (see presence management in the portal)

Messages Not Appearing

• Make sure both clients are subscribed to the same channel
• Check for any error messages in the console
• Verify the publish operation is successful

Build Errors

• Ensure Go version 1.21 or later is installed
• Run go mod tidy to resolve dependencies
• Check that all imports are correct

Get in touch with us

Contact the PubNub devrel team at devrel@pubnub.com if you have any other questions, issues or comments.

License

This project is open source and available under the MIT License.