When you click a remote follow button on a Mastodon profile, the browser sometimes opens the wrong instance for signing in. Instead of your home instance, the button redirects you to a different server where you have no account. This happens because the follow button uses a hardcoded URL that points to a specific instance … Read more
After moving your account to a new Mastodon instance, the remote timeline may stop showing new posts. This often happens because the new instance has not fully connected to the same federated servers as your old instance. The remote timeline relies on active subscriptions to other servers, and these subscriptions do not transfer automatically during … Read more
You boost a post from another Mastodon instance, but the boosted post never shows up in your home timeline or your profile. This can happen even though the original post is still visible and the boost action appeared to succeed. The problem is almost always caused by a server-side mute or block rule applied by … Read more
You type a remote user’s full handle into the Mastodon search box, but the profile does not appear in the results. This happens because Mastodon’s search engine indexes local content by default and relies on federation events to discover remote accounts. Without a prior interaction or a complete federated handshake, the search box returns nothing. … Read more
Mastodon uses the ActivityPub protocol to exchange data between instances. When you post a status, follow a user, or boost a message, Mastodon sends an ActivityPub activity to other servers. This article breaks down how each common Mastodon action translates into an ActivityPub activity type and what fields are included. You will learn the exact … Read more
When you use Mastodon, every action you take—posting, boosting, following—is sent as an ActivityPub message. These messages travel between inbox and outbox endpoints on each server. Understanding how these endpoints work helps you debug federation issues, inspect raw activity flows, and build tools that interact with Mastodon programmatically. This article explains what inbox and outbox … Read more
When a Mastodon post from your instance fails to reach followers on another server, you see no error on your screen. The post publishes locally, but remote users never receive it. This is a federation failure, and it often hides in the background jobs processed by Sidekiq, Mastodon’s task queue system. This article explains how … Read more
When a Mastodon server receives an incoming ActivityPub request from another instance, it must verify that the request truly originated from the claimed actor and was not tampered with in transit. Without this verification, an attacker could forge messages, impersonate users, or inject spam into the federated timeline. Mastodon relies on HTTP Signatures, a standard … Read more
Mastodon uses ActivityPub to communicate between instances. Every message sent to another server must be signed with your private key. Without a valid signature, the receiving server rejects the request as unauthenticated. This article explains the manual process of creating and attaching HTTP signatures to ActivityPub requests for Mastodon federation. Key Takeaways: Manual ActivityPub Signature … Read more
Your Mastodon instance uses cryptographic public keys to sign every message sent to other servers in the fediverse. When those keys expire or leak, you must rotate them to maintain secure federation. However, rotating a public key incorrectly can break communication with thousands of remote instances, causing posts, boosts, and follows to fail silently. This … Read more