Mastodon Federation Signature Verification: HTTP Signature Walkthrough

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

How to Sign ActivityPub Requests for Mastodon Federation Manually

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

Mastodon Federation Public Key Rotation: How to Rotate Without Breakage

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

How to Federate Mastodon With Akkoma Fork Instances Smoothly

Mastodon users often discover that posts from Akkoma fork instances appear broken or fail to load in their federated timeline. This happens because Akkoma and its forks like Pleroma and Honk use a different federation protocol version than Mastodon. This article explains how to adjust your Mastodon server settings and client behavior so federation with … Read more

Mastodon Federation With Sharkey: Compatibility Notes

Mastodon and Sharkey are both part of the ActivityPub-fediverse, but they are not identical software. Mastodon users and Sharkey users often encounter unexpected behavior when interacting across instances. These issues range from missing reactions to broken content warnings. This article explains the key compatibility differences between Mastodon and Sharkey. It covers how federation works between … Read more

How to Federate Mastodon With GoToSocial Instances

You want your Mastodon account to follow users on a GoToSocial instance and have your posts appear in their federated timeline. GoToSocial is a lightweight ActivityPub server that can communicate with Mastodon, but federation is not automatic. This article explains the exact settings and steps required to establish two-way federation between a Mastodon account and … Read more

Mastodon Federation With Lemmy: Limitations of Group Activities

When Mastodon users interact with content from Lemmy, a federated link-aggregation platform, they often encounter unexpected behavior. Replies may appear as top-level comments, votes may not sync correctly, and group-focused actions like posting to a community can fail silently. These issues stem from fundamental differences in how each platform models social objects and activities. This … Read more

How to Federate Mastodon With Kbin and Mbin: Protocol Notes

Mastodon and the link-aggregator platforms Kbin and Mbin both use the ActivityPub protocol to communicate. However, their different base purposes mean federation is not always seamless. A Mastodon user may find that replies to a Kbin thread do not appear, or that following a Kbin magazine from Mastodon produces unexpected behavior. This article explains the … Read more