Marketplace Apps

This guide provides best practices for building chat experiences in marketplace applications, where communication between buyers and sellers is critical to successful transactions.

Channel Types

The built-in Messaging channel type is designed for marketplace use cases and provides a good default configuration. It requires membership for channel access and supports all the features typically needed for buyer-seller communication.

For marketplace apps, we recommend:

• Using the messaging channel type as your starting point
• Creating channels with exactly 2 members (buyer and seller) for most transactions

Recommended Features

Unread Message Reminders

Unread Reminders notify users about messages they haven’t read, helping ensure timely responses. Use them to trigger emails, push notifications, or SMS when a user has unread messages.

Why this matters for marketplaces:

• Buyers waiting for seller responses stay engaged
• Sellers don’t miss potential sales opportunities
• Improves overall transaction completion rates

Enable reminders for your channel type:

// Enable reminders for the messaging channel type
await client.updateChannelType("messaging", {
  reminders: true,
});

// Set reminder interval (default is 5 minutes, max 24 hours)
await client.updateAppSettings({ reminders_interval: 3600 }); // 1 hour

User Average Response Time

The User Average Response Time feature tracks how quickly users typically respond to messages. This is particularly valuable in marketplaces where prompt communication often determines transaction success.

Benefits for marketplaces:

• Buyers can see seller responsiveness before initiating contact
• Marketplaces can highlight responsive sellers with badges or sorting options
• Helps set expectations for communication timelines

Enable this feature in your app settings:

await client.updateAppSettings({
  user_response_time_enabled: true,
});

Once enabled, the avg_response_time field will be included in user responses, allowing you to display responsiveness indicators in seller profiles.

Pending Messages

For marketplaces requiring message moderation, enable pending messages to review content before delivery. This is useful for:

• Preventing spam or fraudulent messages
• Filtering contact information to keep transactions on-platform
• Ensuring compliance with marketplace policies

await client.updateChannelType("messaging", {
  mark_messages_pending: true,
});

Channel Configuration Tips

Recommended Settings

For most marketplace apps, configure your channel type with these settings:

await client.updateChannelType("messaging", {
  typing_events: true, // Show when users are typing
  read_events: true, // Track read status for messages
  reactions: true, // Allow reactions for quick responses
  replies: true, // Enable threaded replies for complex discussions
  uploads: true, // Allow image uploads for product photos
  reminders: true, // Enable unread reminders
});

Custom Data

Use channel and message custom data to enhance the marketplace experience:

// Store listing information on the channel
const channel = client.channel("messaging", {
  members: [buyerId, sellerId],
  listing_id: "listing-123",
  listing_title: "Vintage Camera",
  listing_price: 299.99,
  listing_image: "https://example.com/camera.jpg",
});

Trust and Safety

Moderation

Implement moderation to maintain a safe marketplace environment:

• Use block lists to filter prohibited content
• Enable automod for automatic content filtering
• Set up webhooks to monitor suspicious activity

Blocking Users

Allow users to block problematic buyers or sellers:

// Block a user
await client.blockUser(targetUserId);

// Query channels excluding blocked users
const filter = {
  members: { $in: [currentUserId] },
  app_banned: "excluded", // Exclude channels with banned users
};

Performance Considerations

• Use query channels best practices when loading conversation lists
• Filter by cid when querying specific channels for best performance
• Always include members: { $in: [userID] } in filters for consistent results

Analytics and Insights

Track key metrics to improve your marketplace communication:

• Response times: Use avg_response_time to identify and reward responsive users
• Message volume: Monitor conversation activity to understand engagement
• Unread rates: Track how often reminders are triggered to optimize notification timing