Threads Mastodon List Filtering for Federated Posts: Setup

You want to see only federated posts from specific Mastodon lists inside the Threads app. Threads supports ActivityPub federation, which lets Mastodon users follow Threads profiles, but the app does not have a built-in list viewer for external servers. This article explains how to set up a cross-platform filtering workflow using a secondary Mastodon account and a dedicated list. You will learn how to create a Mastodon list, connect it to your Threads reading workflow, and filter federated content effectively.

What You Need for Threads and Mastodon List Filtering

Threads uses the ActivityPub protocol to share public posts with Mastodon and other federated servers. This means a Threads user with Fediverse sharing enabled can have their public posts appear on Mastodon. However, Threads does not provide a native list or column feature that lets you filter only posts from a specific set of Mastodon users. To achieve list-based filtering, you must use a Mastodon client as a reading tool.

The core requirement is a Mastodon account on any server that supports ActivityPub federation with Threads. Most major Mastodon servers, including mastodon.social and mastodon.online, already federate with Threads. You also need a Mastodon client that supports lists. The official Mastodon web interface, Mastodon for iOS and Android, and third-party clients like Tusky or Ivory all support lists.

The setup involves three steps. First, you create a list in Mastodon. Second, you add Threads profiles to that list. Third, you use the list view in your Mastodon client to read only the federated posts from those profiles. The list does not sync back to Threads. It is a one-way filter that works entirely on the Mastodon side.

Steps to Set Up Mastodon List Filtering for Threads Federated Posts

1. Create a Mastodon account if you do not have one
   Go to joinmastodon.org and sign up on a server. Write down your full handle, for example @yourname@mastodon.social. This handle is required later when adding Threads users to your list.
2. Log in to your Mastodon account in a web browser
   Open your server’s web interface. Click the Preferences link in the top-right menu. This opens your account settings.
3. Navigate to the Lists section
   In Preferences, click Lists in the left sidebar. Click the Create list button. Type a name such as Threads Federated. Click Create.
4. Find the Threads profiles you want to add to the list
   Open the Threads app or website. Go to the profile of a user who has Fediverse sharing enabled. Tap the three-dot menu on their profile and select Copy profile link. The link looks like https://www.threads.net/@username. Write down the username part after the @ symbol.
5. Convert the Threads profile to an ActivityPub handle
   The ActivityPub handle for a Threads user is @username@threads.net. For example, if the Threads username is janedoe, the handle is @janedoe@threads.net.
6. Search for the handle in Mastodon
   In the Mastodon web interface, type the handle into the search bar. Press Enter. Mastodon will show the Threads profile if federation is working. Click the profile to open it.
7. Add the Threads profile to your list
   On the Threads profile page in Mastodon, click the three-dot menu next to the Follow button. Select Add or remove from lists. Check the box next to the list you created in step three. Click Save.
8. Repeat for every Threads user you want to filter
   Add each Threads profile one by one using the same search and list assignment method. This is manual but necessary because Mastodon cannot auto-discover Threads users through a directory.
9. Open your list view in Mastodon
   In the Mastodon web interface, click Lists in the left sidebar. Click the name of your list. You will see only the federated posts from the Threads users you added. This view updates in real time as new posts are published.
10. Use a Mastodon client on mobile for continuous reading
    Install a Mastodon client app such as Mastodon for iOS or Android, or a third-party app like Ivory or Tusky. Log in with your Mastodon account. Navigate to the Lists tab in the app. Select your list to see the filtered federated posts on your phone.

Common Mistakes and Limitations with Threads List Filtering

Threads user does not appear in Mastodon search

If the Threads profile does not show up in Mastodon search, the user has not enabled Fediverse sharing. Open their Threads profile and check their settings. The user must go to Profile > Privacy > Fediverse sharing and toggle it on. Only public posts from users with this setting enabled will appear in Mastodon.

Posts from the list do not update in real time

Mastodon lists update in real time if your client supports streaming. In the web interface, the list column streams new posts automatically. On mobile apps, you may need to pull down to refresh. If posts are delayed by more than a few minutes, check your Mastodon server’s federation status. Some smaller servers process incoming ActivityPub messages slower than larger ones.

List only shows public posts

Mastodon lists can only display public posts from users you follow. If a Threads user has a private profile or has restricted their posts to followers only, those posts will not appear in the list. The list filter works only for content that is publicly federated through ActivityPub.

Cannot add Threads users who do not follow you back

You can add any Threads user to your Mastodon list as long as they have Fediverse sharing enabled. You do not need them to follow you back. The list is a one-way filter on your Mastodon account. It does not require mutual following.

Threads Native Feed vs Mastodon List Filtering: Comparison

Item	Threads Native Following Feed	Mastodon List Filtering
Content source	All Threads users you follow	Only Threads users you manually added to the list
Federation required	No	Yes, Fediverse sharing must be enabled on each Threads profile
Update frequency	Real-time through Threads app	Real-time through Mastodon client streaming
Mobile access	Threads app	Mastodon client app
Ability to sort or group	No built-in list feature	Multiple lists for different groups
Private posts	Visible if you follow the user	Only public posts appear

You can now filter Threads federated posts using a Mastodon list. The workflow requires a secondary Mastodon account and manual setup for each profile. For a more automated approach, explore third-party Mastodon clients that allow list-based columns with keyword filters. This gives you even finer control over which federated posts appear in your reading stream.