Realtime

Yboard Realtime provides pub/sub messaging powered by PostgreSQL triggers, WebSockets, and webhooks.

Overview

The realtime system lets you push updates to connected clients as data changes. Use it for live notifications, chat, collaborative editing, and any feature that needs instant updates.

Technology Stack

Component	Technology	Purpose
Triggers	PostgreSQL	Change detection
Transport	WebSockets	Client connections
Delivery	Webhooks	Server-to-server
Permissions	RLS	Access control

Database Schema

Channels Table

Channels are named topics that clients subscribe to:

Column	Type	Description
`id`	UUID	Primary key
`name`	TEXT	Channel name
`created_at`	TIMESTAMPTZ	Creation time

Messages Table

Messages are published to channels:

Column	Type	Description
`id`	UUID	Primary key
`channel_id`	UUID	Target channel
`payload`	JSONB	Message data
`sender_type`	TEXT	`system`, `user`, or `admin`
`created_at`	TIMESTAMPTZ	Send time

Permission Model

Default Permissions (RLS Disabled)

By default, all authenticated users can subscribe to any channel and publish messages.

Enabling Access Control

Enable RLS on the realtime.channels and realtime.messages tables for fine-grained control:

ALTER TABLE realtime.channels ENABLE ROW LEVEL SECURITY;
ALTER TABLE realtime.messages ENABLE ROW LEVEL SECURITY;

Message Flow

System Events (Database Triggers)

When a database table changes, Yboard can automatically publish notifications:

Row is inserted/updated/deleted in a watched table
PostgreSQL trigger fires
Message is published to the configured channel
Connected WebSocket clients receive the update
Webhook endpoints are called (if configured)

Client Events (User-Initiated)

Clients can also publish messages directly:

Client sends a message via WebSocket or REST API
Message is stored in the messages table
All subscribers on the channel receive the message

WebSocket Events

Client-to-Server Events

Event	Description
`subscribe`	Subscribe to a channel
`unsubscribe`	Unsubscribe from a channel
`publish`	Send a message to a channel

Server-to-Client Events

Event	Description
`message`	New message on a subscribed channel
`subscribed`	Subscription confirmed
`error`	Error occurred

Socket Message Structure

{
  "event": "message",
  "channel": "orders",
  "payload": {
    "type": "INSERT",
    "record": { "id": 1, "status": "paid" }
  }
}

Webhook Delivery

Request Format

Webhooks send POST requests with the message payload:

{
  "channel": "orders",
  "event": "message",
  "payload": { ... },
  "timestamp": "2024-01-15T10:30:00Z"
}

Delivery Guarantees

At-least-once delivery
Automatic retries on failure (3 attempts)
Configurable webhook URLs per channel

Message Retention

Messages are retained based on your project plan. Old messages are automatically cleaned up.

Best Practices

Use specific channels — Don’t subscribe to everything; create channels per feature
Monitor delivery — Check webhook logs for failed deliveries
Enable RLS for production apps to control access
Keep payloads small — Send IDs and let clients fetch full data if needed
Handle reconnections — WebSocket clients should implement reconnect logic

Limitations

Maximum message size: 64 KB
Maximum channels per project: 1000
WebSocket connections are subject to plan limits

Overview

Core Features

App Management

Integrations

Overview

Technology Stack

Database Schema

Channels Table

Messages Table

Permission Model

Default Permissions (RLS Disabled)

Enabling Access Control

Message Flow

System Events (Database Triggers)

Client Events (User-Initiated)

WebSocket Events

Client-to-Server Events

Server-to-Client Events

Socket Message Structure

Webhook Delivery

Request Format

Delivery Guarantees

Message Retention

Best Practices

Limitations

​Overview

​Technology Stack

​Database Schema

​Channels Table

​Messages Table

​Permission Model

​Default Permissions (RLS Disabled)

​Enabling Access Control

​Message Flow

​System Events (Database Triggers)

​Client Events (User-Initiated)

​WebSocket Events

​Client-to-Server Events

​Server-to-Client Events

​Socket Message Structure

​Webhook Delivery

​Request Format

​Delivery Guarantees

​Message Retention

​Best Practices

​Limitations

Overview

Technology Stack

Database Schema

Channels Table

Messages Table

Permission Model

Default Permissions (RLS Disabled)

Enabling Access Control

Message Flow

System Events (Database Triggers)

Client Events (User-Initiated)

WebSocket Events

Client-to-Server Events

Server-to-Client Events

Socket Message Structure

Webhook Delivery

Request Format

Delivery Guarantees

Message Retention

Best Practices

Limitations