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What is Lemmy?

Lemmy is a self-hosted social link aggregation and discussion platform. It is completely free and open, and not controlled by any company. This means that there is no advertising, tracking, or secret algorithms. Content is organized into communities, so it is easy to subscribe to topics that you are interested in, and ignore others. Voting is used to bring the most interesting items to the top.

Major Changes

This release is very large with almost 400 commits since 0.18.5. As such we can only give a general overview of the major changes in this post, and without going into detail. For more information, read the full changelog and linked issues at the bottom of this post.

Improved Post Ranking

There is a new scaled sort which takes into account the number of active users in a community, and boosts posts from less-active communities to the top. Additionally there is a new controversial sort which brings posts and comments to the top that have similar amounts of upvotes and downvotes. Lemmy’s sorts are detailed here.

Instance Blocks for Users

Users can now block instances. Similar to community blocks, it means that any posts from communities which are hosted on that instance are hidden. However the block doesn’t affect users from the blocked instance, their posts and comments can still be seen normally in other communities.

Two-Factor-Auth Rework

Previously 2FA was enabled in a single step which made it easy to lock yourself out. This is now fixed by using a two-step process, where the secret is generated first, and then 2FA is enabled by entering a valid 2FA token. It also fixes the problem where 2FA can be disabled without passing any 2FA token. As part of this change, 2FA is disabled for all users. This allows users who are locked out to get into their account again.

New Federation Queue

Outgoing federation actions are processed through a new persistent queue. This means that actions don’t get lost if Lemmy is restarted. It is also much more performant, with separate senders for each target instance. This avoids problems when instances are unreachable. Additionally it supports horizontal scaling across different servers. The endpoint /api/v3/federated_instances contains details about federation state of each remote instance.

Remote Follow

Another new feature is support for remote follow. When browsing another instance where you don’t have an account, you can click the subscribe button and enter the domain of your home instance in the popup dialog. It will automatically redirect you to your home instance where it fetches the community and presents a subscribe button. Here is a video showing how it works.

Authentication via Header or Cookie

Previous Lemmy versions used to send authentication tokens as part of the parameters. This was a leftover from websocket, which doesn’t have any separate fields for this purpose. Now that we are using HTTP, authentication can finally be passed via jwt cookie or via header Authorization: Bearer <jwt>. The old authentication method is not supported anymore to simplify maintenance. A major benefit of this change is that Lemmy can now send cache-control headers depending on authentication state. API responses with login have cache-control: private, those without have cache-control: public, max-age=60. This means that responses can be cached in Nginx which reduces server load.


Reports are now resolved automatically when the associated post/comment is marked as deleted. This reduces the amount of work for moderators. There is a new log for image uploads which stores uploader. For now it is used to delete all user uploads when an account is purged. Later the list can be used for other purposes and made available through the API.

Cursor based pagination

0.19 adds support for cursor based pagination on the /api/v3/post/list endpoint. This is more efficient for the database. Instead of a query parameter ?page=3, listing responses now include a field "next_page": "Pa46c" which needs to be passed as ?page_cursor=Pa46c. The existing pagination method is still supported for backwards compatibility, but will be removed in the next version.

User data export/import

Users can now export their data (community follows, blocklists, profile settings), and import it again on another instance. This can be used for account migrations and also as a form of backup. The export format is designed to remain unchanged for a long time. You can make regular exports, and if the instance becomes unavailable, register a new account and import the data. This way you can continue using Lemmy seamlessly.

Time zone handling

Lemmy didn’t have any support for timezones, which led to bugs when federating with other platforms. This is now fixed by using UTC timezone for all timestamps.

ARM64 Support

Thanks to help from @raskyld and @kroese, there are now offical Lemmy releases for ARM64 available.

Activity now includes voters

Upgrade instructions

Follow the upgrade instructions for ansible or docker. The upgrade should take less than 30 minutes.

If you need help with the upgrade, you can ask in our support forum or on the Matrix Chat.

Pict-rs 0.5 is also close to releasing. The upgrade takes a while due to a database migration, so read the migration guide to speed it up. Note that Lemmy 0.19 still works perfectly with pict-rs 0.4.

Thanks to everyone

We’d like to thank our many contributors and users of Lemmy for coding, translating, testing, and helping find and fix bugs. We’re glad many people find it useful and enjoyable enough to contribute.

Support development

We (@dessalines and @nutomic) have been working full-time on Lemmy for over three years. This is largely thanks to support from NLnet foundation, as well as donations from individual users.

This month we are running a funding drive with the goal of increasing recurring donations from currently €4.000 to at least €12.000. With this amount @dessalines and @nutomic can each receive a yearly salary of €50.000 which is in line with median developer salaries. It will also allow one additional developer to work fulltime on Lemmy and speed up development.

Read more details in the funding drive announcement.

    7 months ago

    Are there some details about using the new persistent queue in more complex setups? I remember initially it was supposed to run in a separate worker container or so?

    • Dessalines@lemmy.mlOP
      7 months ago

      We need to document this somewhere, but currently you can run two lemmy docker processes, one with this entrypoint:

      entrypoint: lemmy_server --disable-activity-sending

      And one you can call lemmy-federation with this:

      entrypoint: lemmy_server --disable-http-server --disable-scheduled-tasks

      That’s totally optional tho.