When you follow accounts on Pleroma or Misskey servers from your Mastodon account, posts sometimes fail to appear or replies get lost. This happens because Mastodon uses ActivityPub, but Pleroma and Misskey implement parts of the protocol differently. This article explains how to establish federation with these servers, how to search for users across instances, and how to fix the most common connectivity issues.
Key Takeaways: Federating With Non-Mastodon Servers
- Search bar with full handle: Type @user@domain exactly to find accounts on Pleroma or Misskey instances.
- Federation > Domains > Domain block: Check this page in Mastodon admin settings to ensure the remote server is not blocked.
- Moderation > Reports > Resolve: If federation breaks, use this admin tool to re-request the remote server’s nodeinfo and re-establish the connection.
How Mastodon Discovers and Connects to Non-Mastodon Servers
Mastodon relies on the ActivityPub protocol to communicate with other servers. When you interact with an account on a Pleroma or Misskey instance, Mastodon first performs a WebFinger lookup to resolve the user’s ActivityPub ID. It then fetches the remote server’s nodeinfo endpoint to understand its software version and capabilities. If the remote server returns a valid nodeinfo response, Mastodon adds it to its internal federation table and starts exchanging activities like follows, boosts, and replies.
Problems occur when the remote server does not expose its nodeinfo correctly, when the server’s software version uses an incompatible ActivityPub extension, or when the Mastodon admin has manually blocked the remote domain. Pleroma and Misskey both support ActivityPub, but they may use different object types for polls, quote posts, or content warnings. Mastodon silently drops activities it cannot parse, which makes federation appear broken.
Prerequisites for Federation
Your Mastodon instance must have outbound federation enabled. This is on by default on most instances. The remote server must also allow inbound federation from your instance. Some Pleroma and Misskey administrators block specific Mastodon instances due to spam or policy differences. You cannot force federation if the remote admin has blocked your instance.
Steps to Search, Follow, and Interact With Accounts on Pleroma or Misskey
- Open the Mastodon search bar
Click the magnifying glass icon in the Mastodon web interface or press Ctrl+F on the desktop app. This opens the search and explore panel. - Type the full ActivityPub handle
Enter the user’s exact handle in the format @username@domain. For example, @alice@pleroma.social. Mastodon will perform a WebFinger lookup against the remote domain. Do not omit the leading @ symbol. - Wait for the search result to appear
If the remote server responds correctly, the user’s profile appears in the search results within a few seconds. Click the profile to view it. If no result appears, the remote server may be unreachable or blocking your instance. - Click the Follow button
On the remote user’s profile page, click the Follow button. Mastodon sends an ActivityPub Follow activity to the remote server. The remote user must approve the follow if their account is locked. - Check the remote user’s posts in your Home feed
After the follow is accepted, new public posts from that user appear in your Home timeline. If posts do not appear within 15 minutes, the federation link may be incomplete.
If the User Does Not Appear in Search
When a handle does not return results, the remote server may be using a different WebFinger endpoint. Try searching with the full ActivityPub URL instead. Go to the remote user’s profile page on their home instance, copy the URL, and paste it into the Mastodon search bar. Mastodon will parse the URL and attempt to fetch the user’s ActivityPub actor object directly.
Troubleshooting Federation Failures Between Mastodon and Pleroma or Misskey
If you cannot follow a user or their posts do not appear, the issue may be on either side. These are the most common failure patterns and how to fix them.
Remote Server Blocked by Your Mastodon Admin
Your instance administrator may have blocked the remote domain. You cannot bypass this block as a regular user. To check, ask your admin to visit Administration > Federation > Domains > Domain blocks in Mastodon’s admin panel. If the domain appears on the list, the admin must remove the block to allow federation.
Remote Server Returns a 403 or 410 Error
Some Pleroma and Misskey servers return HTTP 403 Forbidden or 410 Gone when Mastodon tries to fetch a user’s profile. This happens when the remote server’s firewall or reverse proxy blocks Mastodon’s user-agent string. The remote admin must allow the Mastodon user-agent or whitelist your instance’s IP range.
Posts Missing From Home Timeline After Follow
If the follow succeeds but posts do not appear, Mastodon may have failed to fetch the remote user’s previous posts. Mastodon only fetches posts made after the follow is accepted. Older posts never appear. If new posts still do not appear, the remote server may be delivering activities to a different inbox URL. The Mastodon admin can check the federation logs at Administration > Federation > Activity log for delivery errors.
Replies Not Showing in Mastodon Threads
Pleroma and Misskey sometimes send replies with an inReplyTo field pointing to a non-Mastodon object. Mastodon may fail to resolve that object if the remote server does not expose it publicly. This is a known limitation. The only fix is for the remote server to ensure all public posts are accessible without authentication.
| Item | Mastodon | Pleroma / Misskey |
|---|---|---|
| Protocol | ActivityPub 1.0 | ActivityPub 1.0 with custom extensions |
| WebFinger endpoint | /.well-known/webfinger | Same but may require resource parameter |
| Nodeinfo endpoint | /.well-known/nodeinfo | Same, but some versions return version 2.0 while Mastodon expects 2.1 |
| Content warning support | summary field in Note object | summary field for Pleroma; Misskey uses contentWarning field |
| Quote post support | Not supported natively | Both support quote posts via custom object types |
| Poll object type | Question type | Pleroma uses Question; Misskey uses custom poll object |
Mastodon drops any activity that uses an unsupported object type. This means quote posts from Misskey and polls from Misskey will not appear in your Mastodon feed. Pleroma’s quote posts also do not federate to Mastodon. These are intentional design differences that no configuration change can fix.
To verify federation is working, ask a friend on the remote server to mention your Mastodon account in a public post. If the mention appears in your Notifications tab, the ActivityPub relay is functional. You can then follow users and interact with their public posts normally. Remember that direct messages and follower-only posts may not federate correctly between different software implementations.