Real-Time Messaging with Pub/Sub in Taubyte

Author: ZaouiAmine

content/posts/messaging-pubsub-taubyte.md

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+---
+title: "Real-Time Messaging with Pub/Sub in Taubyte"
+author: Zaoui Amine
+featured: true
+draft: false
+tags:
+  - tutorials
+  - messaging
+  - pubsub
+  - websocket
+  - real-time
+  - cloud
+image:
+  src: /blog/images/pubsub-messaging.png
+  alt: Real-Time Messaging with Pub/Sub in Taubyte
+summary: Build real-time features with Taubyte's built-in pub/sub messaging. Create WebSocket-enabled channels for chat, notifications, live updates, and more—all from your serverless functions.
+date: 2026-01-14T15:00:00Z
+categories: [Hand-on Learning]
+---
+
+Taubyte includes built-in **pub/sub messaging** that enables real-time communication in your applications. With WebSocket support, you can build chat systems, live notifications, collaborative tools, and more—all directly from your serverless functions.
+
+## Creating a Messaging Channel
+
+From the sidebar, navigate to **Messaging** and click the **+** button.
+
+Configure your channel:
+
+| Field | Description | Example |
+|-------|-------------|---------|
+| Name | Channel identifier | `chat_channel` |
+| Topic Matcher | Topic pattern | `chat/rooms` |
+| WebSocket | Enable WebSocket support | ✅ Toggle on |
+
+Click **Validate** to save.
+
+### Pushing Changes
+
+Click the **green push button**, review your changes, add a commit message, and push to the repository.
+
+Build and deploy:
+
+```bash
+dream inject push-all
+```
+
+## Connecting Pub/Sub to Functions
+
+Now let's create a function that provides WebSocket URLs for clients to connect.
+
+### Create the WebSocket URL Function
+
+Navigate to **Functions** and click **+**:
+
+1. Click **Template Select**
+2. Choose **Go** and **get WebSocket URL**
+3. Set the domain to your generated domain
+4. Set the path to `/api/ws`
+
+Switch to the **Code** tab and replace with:
+
+```go
+package lib
+
+import (
+    "crypto/sha256"
+    "encoding/hex"
+    
+    "github.com/taubyte/go-sdk/event"
+    "github.com/taubyte/go-sdk/pubsub"
+)
+
+//export getWebSocketURL
+func getWebSocketURL(e event.Event) uint32 {
+    h, err := e.HTTP()
+    if err != nil {
+        return 1
+    }
+
+    // Get room name from query parameters
+    query := h.Query()
+    room := query.Get("room")
+    
+    if room == "" {
+        h.Write([]byte(`{"error": "room parameter required"}`))
+        return 1
+    }
+
+    // Hash the room name to create a unique channel
+    hash := sha256.Sum256([]byte(room))
+    channelName := hex.EncodeToString(hash[:])
+
+    // Open or create the pub/sub channel
+    channel, err := pubsub.Open("chat/rooms/" + channelName)
+    if err != nil {
+        h.Write([]byte(`{"error": "failed to open channel"}`))
+        return 1
+    }
+    defer channel.Close()
+
+    // Get WebSocket URL for this channel
+    wsURL, err := channel.WebSocketURL()
+    if err != nil {
+        h.Write([]byte(`{"error": "failed to get websocket url"}`))
+        return 1
+    }
+
+    h.Write([]byte(wsURL))
+    return 0
+}
+```
+
+This function:
+1. Reads the `room` query parameter
+2. Hashes it to create a unique channel name
+3. Opens (or creates) the pub/sub channel
+4. Returns a WebSocket URL for clients to connect
+
+Validate and push, then trigger a build:
+
+```bash
+dream inject push-all
+```
+
+## Testing with wscat
+
+### Install wscat
+
+First, install the WebSocket testing tool:
+
+```bash
+npm install -g wscat
+```
+
+### Get a WebSocket URL
+
+Request a WebSocket URL for a room:
+
+```bash
+curl "http://your-domain.blackhole.localtau:14529/api/ws?room=tau"
+```
+
+Response (example):
+```
+/ws/channel/a8f5f167f44f4964e6c998dee827110c...
+```
+
+### Connect Two Clients
+
+Open **two terminal windows** to simulate a chat:
+
+**Terminal 1:**
+```bash
+wscat -c "ws://your-domain.blackhole.localtau:14529/ws/channel/a8f5f167f44f4964e6c998dee827110c..."
+```
+
+**Terminal 2:**
+```bash
+wscat -c "ws://your-domain.blackhole.localtau:14529/ws/channel/a8f5f167f44f4964e6c998dee827110c..."
+```
+
+Now type in one terminal—it appears instantly in the other! 
+
+Your **pub/sub WebSocket is alive**.
+
+
+## Use Cases
+
+| Use Case | Implementation |
+|----------|----------------|
+| Chat rooms | Per-room channels with WebSocket |
+| Live notifications | Global channel, functions publish |
+| Real-time dashboards | Data channels, subscribe from frontend |
+| Collaborative editing | Document-specific channels |
+| Game state sync | Game room channels |
+
+
+## Conclusion
+
+You've learned how to:
+
+1. **Create messaging channels** with WebSocket support
+2. **Build functions** that return WebSocket URLs
+3. **Test with wscat** for real-time communication
+4. **Build browser clients** for chat applications
+
+Pub/sub is the foundation for real-time features in your applications—from chat to live notifications to collaborative tools.
+
+Next, learn about [Applications](/blog/posts/taubyte-applications) for organizing resources into logical units.
+