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Message reactions provide a lightweight way to respond to messages with emoji without sending a full message.

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Overview

Reactions allow you to:
  • Respond quickly with emoji
  • Show agreement or acknowledgment
  • Express emotions without interrupting conversation
  • See who reacted with each emoji
  • Use standard Unicode emoji
  • Use custom organization emoji (if configured)

Quick Feedback

React instantly without composing a message

One Per User

Each user can use each emoji once per message

Toggleable

Click again to remove your reaction

Custom Emoji

Use organization-specific custom emoji

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Adding Reactions

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Quick React

Add a reaction to any message:
  1. Hover over a message
  2. Click the reaction icon (😀) that appears
  3. Select an emoji from the picker
  4. Or click a frequently used emoji
The reaction appears immediately on the message.

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Reaction Picker

The emoji picker includes:
  • Recent - Your recently used emoji
  • Frequently Used - Popular reactions
  • Emoji Categories - People, Nature, Food, Activities, etc.
  • Custom Emoji - Organization-specific emoji (if configured)
  • Search - Find emoji by name or keyword

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Keyboard Shortcuts

Quick reactions with hotkeys:
  • 👍 - Thumbs up
  • ❤️ - Heart
  • 😂 - Laughing face
  • 🎉 - Party popper
  • 🚀 - Rocket
Hover over a message and press the corresponding number key (1-5) to add these quick reactions.

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Removing Reactions

Remove your reaction:
  1. Click your reaction emoji on the message
  2. The reaction is instantly removed
Or:
  1. Hover over the message
  2. Click the reaction icon
  3. Click the highlighted emoji to toggle it off

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Viewing Reactions

See who reacted to a message:
  1. Hover over a reaction count
  2. Tooltip shows list of users who reacted
  3. Your reaction is highlighted
Reactions are grouped by emoji with a count: 
👍 5    ❤️ 3    🎉 2

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Reaction Behavior

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One Reaction Per Emoji

Each user can react once with each emoji:
  • ✅ You can add 👍 and ❤️ to the same message
  • ❌ You cannot add 👍 twice to the same message
  • Clicking an emoji you’ve already used removes it (toggle behavior)

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Real-Time Updates

Reactions sync instantly:
  • See reactions from other users immediately
  • Reaction counts update in real-time
  • Optimistic updates for instant feedback
  • Automatic sync via Electric SQL

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Persistence

Reactions are permanently stored:
  • Survive app restarts
  • Sync across all your devices
  • Visible to all channel members
  • Deleted when message is deleted

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Custom Emoji

Organizations can add custom emoji:

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Adding Custom Emoji

  1. Go to Organization Settings → Custom Emoji
  2. Click Add Emoji
  3. Upload an image file (PNG, GIF recommended)
  4. Enter a short name (e.g., “success”)
  5. Save the custom emoji
Custom emoji appear in the emoji picker under the Custom category.

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Using Custom Emoji

  • Type :shortname: in messages (e.g., :success:)
  • Select from the emoji picker
  • Use in reactions like standard emoji
  • Available only in the organization where created
Custom emoji must be uploaded by organization admins or owners. Rate limited to 5 uploads per hour.

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Reaction Notifications

Receive notifications when someone reacts to your message:
  • Notification appears in your notification center
  • Shows who reacted and with which emoji
  • Links directly to the message
  • Can be disabled per channel
See Notifications for more details.

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Use Cases

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Quick Acknowledgment

Use 👍 to acknowledge you’ve seen and understood a message without adding noise to the conversation.

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Voting and Polls

Create informal polls: 
Which design do you prefer?
React 1️⃣ for Option A
React 2️⃣ for Option B

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Showing Support

Use ❤️ to show support or appreciation for someone’s message or achievement.

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Indicating Status

Use reactions to show task status:
  • ✅ - Done
  • 🚧 - In progress
  • ⏸️ - Blocked

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Celebrating Wins

Use 🎉, 🚀, or 🏆 to celebrate team wins and milestones.

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Reaction Analytics (Coming Soon)

Future features:
  • Most used emoji in organization
  • Reaction trends over time
  • Top reactors leaderboard
  • Custom emoji usage statistics

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Technical Details

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Data Model

Each reaction includes: 
{
  id: string           // Reaction ID
  messageId: string    // Parent message
  channelId: string    // Channel context
  userId: string       // User who reacted
  emoji: string        // Emoji character or custom emoji ID
  createdAt: Date     // When reaction was added
}

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Unique Constraint

Database enforces uniqueness: 
UNIQUE (messageId, userId, emoji)
This prevents duplicate reactions from the same user with the same emoji on the same message.

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RPC Operations

Toggle Reaction: 
rpcClient.messageReactionToggle({
  messageId: string,
  channelId: string,
  emoji: string
})
Returns: 
{
  wasCreated: boolean,              // true if created, false if removed
  data?: MessageReaction,           // reaction data if created
  transactionId: string            // for optimistic updates
}
Create Reaction: 
rpcClient.messageReactionCreate({
  messageId: string,
  channelId: string,
  emoji: string
})
Delete Reaction: 
rpcClient.messageReactionDelete({
  id: string
})

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Database Indexes

Optimized queries with indexes on:
  • channel_id - Channel reactions
  • message_id - Message reactions
  • user_id - User’s reactions
  • message_id, user_id, emoji - Uniqueness check

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Emoji Format

Reactions support: Standard Emoji:
  • Stored as Unicode characters (e.g., ”👍”, “❤️”)
  • Cross-platform compatible
  • Maximum 50 characters (for multi-codepoint emoji)
Custom Emoji:
  • Stored as custom emoji ID reference
  • Resolved to image URL in frontend
  • Organization-specific

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Real-Time Sync

Reactions sync via Electric SQL:
  • Instant delivery to all channel members
  • Optimistic updates for instant UI feedback
  • Automatic conflict resolution
  • Offline support with sync on reconnect

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Permissions

Add Reactions:
  • Must be channel member
  • Rate limited with message operations (60/min)
Remove Reactions:
  • Only your own reactions
  • Or organization admin/owner
View Reactions:
  • All channel members

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