How to Add a Mastodon Hashtag Subscription via Third-Party Client

Mastodon does not include a built-in feature to subscribe to a hashtag and receive push notifications for new posts. The official web interface and mobile apps allow you to follow hashtags, but they do not alert you in real time. Third-party clients such as Tusky, Fedilab, and Mona fill this gap by offering dedicated hashtag subscription systems. This article explains how to set up hashtag subscriptions in three popular third-party Mastodon clients and what to do if the feature stops working.

How Hashtag Subscriptions Work in Third-Party Clients

Mastodon’s core API supports following hashtags, but the official clients and the web interface do not expose a subscribe button with notification controls. Third-party developers use the Mastodon streaming API to listen for new posts that match a hashtag. When a match is found, the client can display the post in a dedicated timeline column or send a push notification.

Each client implements this feature differently. Some treat a hashtag subscription as a persistent column that lives alongside your home and local timelines. Others treat it as a filter that triggers device-level alerts. Before you start, make sure your third-party client is updated to the latest version. Older builds may lack the streaming API endpoint required for real-time updates.

Steps to Add a Hashtag Subscription in Tusky for Android

1. Open Tusky and tap the three-dot menu
   Tap the three vertical dots in the top-right corner of the app to open the side navigation drawer.
2. Select Hashtags from the drawer
   In the navigation drawer, tap the Hashtags option. This opens a screen that lists any hashtags you already follow.
3. Tap the plus (+) icon
   In the top-right corner of the Hashtags screen, tap the plus icon to add a new hashtag subscription.
4. Enter the hashtag without the # symbol
   Type the hashtag name without the hash character. For example, type MastodonTips not #MastodonTips. Tap Add.
5. Enable push notifications
   After adding the hashtag, Tusky prompts you to enable push notifications for new posts. Tap Allow to receive alerts. If you skip this step, you can later enable notifications from the Hashtags screen by tapping the bell icon next to the hashtag.

Steps to Add a Hashtag Subscription in Fedilab for Android

1. Open Fedilab and go to Lists
   From the main screen, tap the menu icon in the top-left corner. In the drawer, tap Lists.
2. Tap the plus (+) icon to create a new list
   In the Lists screen, tap the plus icon in the bottom-right corner. Fedilab uses lists as containers for hashtag subscriptions.
3. Name the list and choose Hashtag type
   Enter a name for the list, such as Tech News. From the list type options, select Hashtag. This tells Fedilab to treat the list as a hashtag subscription.
4. Enter the hashtag and save
   Type the hashtag name without the # symbol. Tap Save. Fedilab now shows a new timeline tab named after your list that displays only posts containing that hashtag.
5. Configure notification settings
   Tap the three dots next to the list name in the Lists screen. Select Notifications and choose whether to receive push alerts for each new post. You can also set a custom notification sound.

Steps to Add a Hashtag Subscription in Mona for iOS

1. Open Mona and tap the gear icon
   Tap the gear icon in the bottom-right corner to open the Settings screen.
2. Select Timeline under Columns
   In the Settings screen, scroll to the Columns section and tap Timeline.
3. Tap Add Column and choose Hashtag
   Tap the Add Column button. From the list of column types, select Hashtag.
4. Enter the hashtag and confirm
   Type the hashtag name without the # symbol. Tap Done. Mona adds a new column to your main timeline view that shows posts matching the hashtag.
5. Enable push notifications for the column
   Long-press the new column header. Tap Notifications and toggle Push on. Mona will now send a push alert whenever a new post with the hashtag appears.

Common Issues When Adding Hashtag Subscriptions

Hashtag subscription does not appear after adding it

If the hashtag column or list does not show any posts, the client may not have connected to the Mastodon streaming API. Force-close the app and reopen it. On Android, go to Settings > Apps > [Client Name] > Force Stop. On iOS, swipe the app away from the app switcher. After reopening, the subscription should start populating.

Push notifications do not arrive

Push notifications rely on device-level permissions. On Android, go to Settings > Apps > [Client Name] > Notifications and confirm that Show notifications is enabled. On iOS, go to Settings > Notifications > [Client Name] and set Allow Notifications to on. Also check that the client’s own notification settings have the hashtag subscription set to push rather than silent.

Hashtag stream stops updating after a few minutes

Some Mastodon instances impose rate limits on streaming API connections. If the client maintains too many open streams, the instance may drop the oldest one. Reduce the number of active hashtag subscriptions. Close any unused columns or lists. If the problem persists, try using a different third-party client that implements connection pooling.

Third-Party Client Hashtag Subscription Features

Item	Tusky (Android)	Fedilab (Android)	Mona (iOS)
Push notifications	Yes, per hashtag toggle	Yes, per list with custom sound	Yes, per column toggle
Dedicated timeline column	No, shows in Hashtags screen	Yes, appears as a tab	Yes, appears as a column
Supports multiple hashtags	Yes, adds each separately	Yes, one hashtag per list	Yes, one hashtag per column
Requires # symbol when adding	No	No	No

After setting up your hashtag subscriptions, you can monitor specific topics without manually searching. Try combining a hashtag subscription with a saved search in the same client to filter results further. For example, in Fedilab you can create a list for #TechNews and then apply a keyword filter to exclude posts from certain accounts.