By default, Misskey has a number of issues affecting its ability to federate with other federated ActivityPub services, such as Pleroma and Mastodon. This article contains a set of tips to help mitigate these problems.
Pleroma related issues
User profile character limits
In Pleroma, users may have very long user profiles and nicknames, which tends to conflict with Misskey's limits for these fields. Misskey's default behavior is to instead ignore these users, breaking federation with them.
As a temporary fix, a patch has been made to mitigate this issue, which can be found here on this wiki. Applying this patch will change Misskey's behavior to instead truncate fields too long to fit into its database, thus restoring federation with afflicted users.
General ActivityPub related issues
Signing ActivityPub requests
Some other ActivityPub Software can have issues federating with Misskey with the default settings. This is because especially with Mastodon, signing ActivityPub requests is necessary.
Because of this you should enable the
signToActivityPubGet option in
.config/default.yml. This option should already be on the last line of the example configuration included with Misskey.