Mattermost Social Preview Plugin

A Mattermost plugin that automatically displays rich previews for social media URLs. Supports Mastodon, Bluesky, Twitter/X, Threads, TikTok, and Instagram. Works on all platforms including web, desktop, iOS, and Android.

Features

• Multi-platform - Previews from Mastodon, Bluesky, Twitter/X, Threads, TikTok, and Instagram
• Generic link previews - Fallback Open Graph previews for any URL not handled by a platform-specific handler
• Cross-platform - Works on all Mattermost clients (web, desktop, mobile)
• Automatic detection - Detects social media URLs and generates previews inline
• Rich previews - Shows author, avatar, content, images, web url previews and video links
• Mastodon reply context - Shows parent posts for Mastodon replies (both API replies and embedded quote links)
• No configuration - Works out of the box with default settings
• Privacy-friendly - Only fetches public posts, no authentication required. Strips tracking params from urls.

The Problem

The standard web preview Mattermost provides is usually pretty bad for Mastodon posts (attached thumbnail is tiny, the displayed text is limited and gets cut off and looks ugly) and doesn't preview anything at all for most of the other popular social media platforms. Given people share links to these around all the time, I wasn't happy with this and wanted to do better.

Mattermost's default Mastodon preview:

This plugin's Mastodon preview:

Mattermost did no previews at all with TikTok and many other social media links. This plugin's Tiktok preview:

You can get the plugin at GitHub, follow the installation instructions there.