We are getting closer to the next major release. This version will have many breaking changes, so we are listing them here for app and client developers to adjust their projects.

As we prepare for the release of Lemmy 0.19.0, we’d like to provide any app or client developers ample time to upgrade their apps, as well as discover any problems, before we do the release. This will be at least 4 weeks from now (but likely longer).

Server admins can also upgrade to the latest release candidates for testing. Be aware that they are still unstable and shouldn’t be used in production. As with any upgrade it is important to have working backups in place.

It should be possible for clients to support both Lemmy 0.18 and 0.19 without major workarounds. If backwards compatibility is causing you trouble, comment below and we will help to find a solution.

To test, you can point your app to the following test instance running a release candidate of 0.19.0: https://voyager.lemmy.ml

A diff of API changes is here: lemmy-js-client API changes from 0.18.3 -> 0.19.0-rc’s

Note for developers not using typescript or rust:

If you’d like to auto-generate an API client for your language, you can try out @MV-GH’s lemmy_openapi_spec, or (if in kotlin), use Jerboa’s script here.

Major Changes

Authentication

Previous Lemmy versions used to take authentication as query/post parameters. This is insecure and unnecessarily complicated. With 0.19, the jwt token can be passed either as cookie with name auth, or as header in the form Authorization: Bearer .

A major advantage is that this allows us to send proper cache-control headers, with responses to unauthenticated users being cacheable. It also prevents token leaks in web server logs. The login and registration endpoints attempt to set the cookie automatically. If that is supported on your platform, you don’t have to worry about the authentication token at all.

In order for your client to be compatible with both Lemmy 0.18 and 0.19, you should send auth in both ways. Meaning with each API call, send the old auth query/post parameter, as well as the new header or cookie.

A few PRs detailing these changes:

Users can block instances

Users can now block instances, so that their communities are hidden from listings. This is done via POST /api/v3/site/block with parameters int instance_id, bool block.

https://github.com/LemmyNet/lemmy/pull/3869

New sort options

A new scaled sort option has been added. This sort is identical to the Hot sort, but also takes into account the number of each community’s active monthly users, and so helps to boost posts from less active communities to the top.

https://github.com/LemmyNet/lemmy/pull/3907

2FA / TOTP Rework

Two-Factor-Authentication is now enabled in a two-step process to avoid locking yourself out. Now a secret needs to be generated first with POST /api/v3/user/totp/generate (no parameters). The generated token needs to be added by the user to an authenticator app.

Once this is completed, 2FA can be enabled with POST /api/v3/user/totp/update. This takes a string parameter totp_token (generated by authenticator app), and boolean enabled. 2FA can be disabled again with the same update endpoint. Additionally, the 2FA algorithm has been changed to SHA1 for better compatibility.

The update disables 2FA for all accounts, so that users who are locked out can use their accounts again, and to ease the transition to the SHA1 algorithm.

https://github.com/LemmyNet/lemmy/pull/3959

Timestamps now include timezone

Previous Lemmy versions used timestamps without any timezone internally. This caused problems when federating with other software that uses timezones.

Going forward, all timestamps in the API are switching from timestamps without time zone (2023-09-27T12:29:59.113132) to ISO8601 timestamps (e.g. 2023-10-29T15:10:51.557399+01:00 or Z suffix). In order to be compatible with both 0.18 and 0.19, parse the timestamp as ISO8601 and add a Z suffix if it fails (for older versions).

https://github.com/LemmyNet/lemmy/pull/3496

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.

https://github.com/LemmyNet/lemmy/pull/3872

New endpoints for export/import of user settings data

Users can now export their profile settings data (including subscriptions and blocklists) via GET /api/v3/user/export. The returned JSON data should not be parsed by clients, but directly downloaded as a file. Backups can be imported via POST /api/v3/user/import.

https://github.com/LemmyNet/lemmy/pull/3976

Make remove content optional during account deletion

When a user deletes their own account using POST /api/v3/user/delete_account, there is a new parameter called delete_content. If it is true, all posts, comments and other content created by the user are deleted (this is the previous default behaviour). If it is false, only the user profile will be marked as deleted.

https://github.com/LemmyNet/lemmy/pull/3817

Outgoing Federation Queue

The federation queue has been rewritten to be much more performant and reliable. This is irrelevant for client developers, but admins should look out for potential federation problems. If you run multiple Lemmy backends for horizontal scaling, be sure to read the updated documentation and set the new configuration parameters. The Troubleshooting section has information about how to find out the state of the federation queues.

https://github.com/LemmyNet/lemmy/pull/3605

  • @echo64@lemmy.world
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    1265 months ago

    scaled ranking is gonna be a gamechanger, I don’t subscribe to a few communities just because they will blow out my other ones

    • @Kichae@lemmy.ca
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      755 months ago

      Honestly, scaled ranking and user-level server bans are huge deals. This is really exciting.

      • @MBM@lemmings.world
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        355 months ago

        Also, importing/exporting user data will make it easier to transfer your account to a different instance. I’m mostly excited for scaled ranking though.

        • @____@infosec.pub
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          75 months ago

          I agree - I don’t even sub to all that many communities, and just had to move instances this week - it was a clunky process to say the least.

    • Rikudou_Sage
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      115 months ago

      I created a workaround for that at https://schedule.lemmings.world - you can select which communities you want to be notified about new posts daily/weekly/monthly etc. You can also create multiple such schedules for a single community, meaning you can easily get notified every hour if that’s what you wish.

    • 👁️👄👁️
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      115 months ago

      Yeah, I can’t wait to see how this works in practice. Wonder if they’ll find something similar with active posts, and hopefully a way to not see the same post over and over.

  • @harpuajim
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    665 months ago

    Off topic here but from the looks of it Lemmy requires a serious amount of time and work. Is the development team working on this full time in lieu of a full time programming job? Or is a passion project in addition to your real live duties?

    • DessalinesOPA
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      1065 months ago

      @nutomic@lemmy.ml and I work full-time on lemmy, and there’s a large number of additional contributors, helping out not just with code, but with translations, documentation, moderation, etc. As donations increase, we’d like to add more full-time/paid devs to our little co-op (we’re in the process onboarding two more rn).

  • froggers
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    565 months ago

    Absolutely stellar work from every person who contributes to Lemmy. With each new release Lemmy is becoming more and more accessible and just plain better.

  • @Hubi@feddit.de
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    325 months ago

    Thank you all for your hard work in making Lemmy even better. I’m really happy to see the ability for users to block instances themselves, seems like it was a widely requested feature.

    • Sabata11792
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      155 months ago

      We can finally stop seeing de-federation post crying about other political views.

      • @Hubi@feddit.de
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        195 months ago

        I think the main advantage will be that it’s much easier to choose a home instance, because you don’t have to select one that defederates according to your own preferences. It’ll make Lemmy more accessible for new users.

    • @blackbrook@mander.xyz
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      135 months ago

      And further thanks for taking this much care wrt backwards compatibility and helping clients avoid breaking.

    • DessalinesOPA
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      125 months ago

      Thanks! Ya that one should be very useful, and now apps won’t have to hack it on afterwards.

  • @rip_art_bell@lemmy.world
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    295 months ago

    helps to boost posts from less active communities to the top

    Nice!! This and the instance-blocking are welcome changes.

    • 𝘋𝘪𝘳𝘬
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      -15 months ago

      This and the instance-blocking are welcome changes.

      The people at lemmygrad, kbin, and hexbear will be so mad about that!

  • @BitingChaos@lemmy.world
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    265 months ago

    Users can block instances

    Finally!

    I’ve had enough creepy/disgusting furry and pedophile drawings on my feed. That “yiffit” instance will be the first that I block.

      • @RickyRigatoni
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        25 months ago

        Doesn’t sound like it’ll block the users so the battle is only half won.

        • Clay_pidgin
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          35 months ago

          I use the app Connect for Android which has an insurance blocking feature already. I don’t see posts or communities from their users, and when they comment on a post I can see, the content of their comment is collapsed by default. I can still see it if I click. It’s a good system, I think.

          • @RickyRigatoni
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            25 months ago

            Yeah it would be nice for a web version of connect to use on desktop. Can’t type to save my life on mobile, fingies too strong.

            • Clay_pidgin
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              15 months ago

              Maybe you have a career ahead of you in massage or clay sculpting!

  • YⓄ乙
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    205 months ago

    Hotdamn! We’re so going to take over all social media out there.

  • Rikudou_Sage
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    185 months ago

    Just a note: Datetime without timezone is a valid ISO8601 datetime, so no library should fail when trying to parse the old dates.

    • Admiral Patrick
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      55 months ago

      Yeah, I took out the +Z concatenation in my frontend ahead of 0.19.0 support, and everything works fine without it.

      • Rikudou_Sage
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        15 months ago

        Well, probably not fine - if it follows the standards, it should assume the local timezone, so unless your server is in the UTC timezone, you may be showing wrong dates.

        • Admiral Patrick
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          5 months ago

          Well, all the places that used that were passing it to a function that fuzzed the time somewhat. e.g. 2023-09-01 13:20:55.123456 becomes “1 mo ago”. So timezone really didn’t provide any benefit there.

  • @kevincox
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    175 months ago

    A major advantage is that this allows us to send proper cache-control headers, with responses to unauthenticated users being cacheable.

    Note for people using Cloudflare that it has some pretty dumb caching behaviour so you will want to make sure to disable it for any endpoint that may be authenticated.

    I don’t think I wrote down the exact behaviour but IIRC it basically ignores the Vary header. So it will serve the “unauthorized” page to future requests that have credentials. I think it will at least not cache responses with authentication if vary is included but it will cache the unauthenticated ones.

  • @4am@lemm.ee
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    75 months ago

    Shouldn’t SHA1 not be used for anything since it is insecure? Why not SHA256?

    • Unruffled
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      185 months ago

      Because hardly any popular 2fa authenticator apps have implemented sha256 yet. No point putting the chicken before the egg.

    • DessalinesOPA
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      175 months ago

      We currently use SHA-256 but too many authenticator apps ignore the alg parameter, and don’t know how to support the spec which should allow different variants.

    • TheCaconym [any]
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      5 months ago

      While SHA1 might be considered problematic security-wise in terms of collision (using it for certs today would be very bad, for example), it is not problematic in terms of preimage attacks (even MD5 isn’t broken that way IIRC), which is what truly matters in the context of 2FA / TOTPs

      As for “why not SHA256”, compatibility