Galacticraft 5 is a full rewrite with no addon compatibility and no release date

A rewrite from the ground up, not a version bump

The repository describes Galacticraft 5 as the classic Minecraft space mod, rewritten from the ground up for modern versions of the game. The word rewritten is doing the work here, and the project confirms it when it answers the addon question: Galacticraft 5 is a complete rewrite and does not have backwards compatibility with the old addon API. For a player that means a new set of planets, machines and progression to learn. For the ecosystem around it, it means something considerably heavier. Every addon built against the previous API has to be ported or dropped, and none of that work is shared for you. The repository is written in Java, uses Gradle with the Kotlin DSL for its build, and is licensed under MIT, so the code itself is permissive. What is uncertain is the API surface around it, and the API is the part other mods depend on.

Fabric first, and Forge only after a playable alpha

The platform plan is explicit in the common questions section. Forge development will start after the project has a survival-playable alpha build out for Fabric. That ordering is worth understanding as a policy rather than a schedule. The team is choosing to prove the game works before spending effort on the second loader, and the phrase survival playable is doing specific work: an alpha you can actually live in, not a tech demo. It also means anyone running a Forge based pack today gets nothing from this branch of work, while Fabric users get the early builds. The repository topics reflect the same split, listing fabricmc and fabricmc-mod alongside galacticraft and minecraft. If your decision depends on the loader rather than on the features, the answer from the project documentation is that Fabric is where the work is happening now.

There is no ETA, and the alpha announcement is on Discord

Asked when Galacticraft 5 will be released, the answer is that there is currently no ETA for a release, with a request to keep an eye on the Discord server for an alpha release announcement. The rest of the project communication lives in the same place. The readme points to the faq channel in the Discord for more information, and the repository also links a Twitch channel for the developers. The honest reading is that the project treats its community channels as the primary release channel rather than a GitHub release page, and that is consistent with the release mechanics described below. There are no GitHub releases for this repository at all, so a version number in the wild will not correspond to a tagged artefact you can diff against. If you need to know what you are running, you will be reading commit identifiers and build dates, not semantic versions.

Pre-alpha builds are per-commit artefacts with a corruption warning

The build and distribution model is unusual and worth reading carefully. Pre-alpha builds are created after every commit to the main branch of the repository, and they can be found on the GitHub Actions tab, where you select a commit and look for the Artifacts section at the bottom. There is no release page and no curated download, just the output of continuous integration for whichever commit you choose. The project attaches an important warning to these builds. Galacticraft 5 is still under development, it is possible that saves will become corrupted or unloadable after updates, it is strongly discouraged to use these builds for anything but testing, and no support will be provided regarding their use. That is four separate statements in one note and each of them matters. A build that corrupts a world is not a build to put on a server with other people's data, and the explicit no support clause means that when it breaks, the Discord is a community channel and not a support desk.

The addon ecosystem has to be ported, and that cost lands on authors

The compatibility answer is the one that most affects other people. Galacticraft 5 will not work with Galacticraft 4 addons, because the old addon API is not carried over. That is a deliberate engineering decision rather than an oversight, since a rewrite that preserves the old API would preserve its constraints too, but it transfers real work to addon authors and to the people who maintain modpacks. For a server operator or a modpack maintainer, the practical sequence is the following. Existing Galacticraft 4 addons do not carry over, so a pack built on them either stays on the older line or needs replacements that do not exist yet. The documentation says nothing about a compatibility layer, a migration guide for addon authors, or a schedule for the old API to be reimplemented. So the addon ecosystem around this project is effectively a second project running in parallel, and whether it becomes viable depends on authors rather than on the core team. This is also the clearest case where choosing the wrong line costs you real time rather than a few settings.

Contributing means a human review and a green build

The contributing section is short and sets a clear bar. The project welcomes and encourages community contributions, but asks that the contributing guidelines be read first. Pull requests require at least one team member's approving review and a successful build before they will be merged. Two things follow from that sentence. A pull request is not merged on the strength of the code alone, since a green build is also required, which means the Gradle build has to pass in their environment and not just on your machine. And the reviewing load sits with the team, so a large queue of unapproved pull requests is a realistic state for a project of this size. Translations are handled through the same document, with a separate translations section that anyone interested in helping translate Galacticraft into different languages is pointed to. The repository also carries a .githooks directory, which is consistent with a project that wants local checks to run before a commit.

Repository layout, licence and what a fresh reader can find

The repository is a Gradle project with the usual structure for a Minecraft mod: a src/ directory for the game code, a tools/ directory, build.gradle.kts and settings.gradle.kts for the build definition, gradle.properties, and the Gradle wrapper as gradlew and gradlew.bat so a build does not need a system Gradle. There is also a .githooks/ directory and a file named capes_roles.json at the root, which sits alongside the Discord and Twitch links in the readme and suggests a mapping between in-game capes and community roles, though the file itself is not described. The licence is MIT with a LICENSE file at the root, and the last push to the repository was on 2026-10-19, so the code is being worked on actively even though nothing is released. The gap between those two facts is the whole story of this project. There is no installation documentation in the readme because there is nothing to install yet in the ordinary sense, the artefact is a per-commit build, and the readme says plainly that these builds are for testing only.

Editorial conclusion

Adopt Galacticraft 5 only if you are willing to test a pre-alpha rewrite, accept that saves may be corrupted by updates, and are ready to do addon work yourself, because the old addon API is not carried over. Do not adopt it for a live server or a modpack that depends on Galacticraft 4 addons, since the project documents no ETA, provides no support for these builds and states that Forge support comes only after a survival playable alpha on Fabric. Before you install anything, pull a specific pre-alpha artefact from the GitHub Actions tab, keep a backup of your world, and read the contributing guidelines if you intend to help.

Frequently asked questions

Official sources

1. Issues
2. License: MIT
3. README
4. TeamGalacticraft/Galacticraft on GitHub