Horizon
horizon-rust/horizonReviewed by AI
Radar found strong risk signals in this project. It stays visible so you can read the evidence, but it is left out of rankings and recommendations.
What it does
An unofficial, free rewrite of Minecraft: Java Edition 26.3 in Rust. It reads vanilla saves, makes the same terrain and follows the same rules, checked against the Java game by "more than 300 differential harnesses". You install it with the Horizon launcher, which needs a Microsoft account that owns Java Edition and prepares the files from your own copy. Extras include distant terrain up to 1024 chunks, controllers, a minimap and a server page. Java mod jars do not run. The project's own status page counts "Player-visible gaps: 833 open".
How easy it is to install
B · installer plus one simple step · Windows
- Windows B
- macOS B
- Linux B
B on Windows, Linux and Mac: the launcher releases ship ready binaries (horizon-launcher-windows-x64.zip, horizon-launcher-linux-x86_64.tar.gz, horizon-launcher-macos-arm64.dmg and horizon-launcher-macos-x64.dmg) and the launcher "installs and updates the game, prepares its files from your copy of Minecraft, and updates itself". The extra steps are the ones the README lists: "a Microsoft account that owns Java Edition" and "a GPU with Vulkan or OpenGL 3.3 (Linux), Vulkan or DirectX 12 (Windows), or a Mac (Apple Silicon, or Intel from the next Nightly)".
Numbers on GitHub
- Stars
- 5,386on Oct 31, 2026
- Downloads
- 501,359227,600 this week
- Growth
- +2,869stars in 5 days
Stars over time
Facts
- Runs on
- Windows, macOS, Linux
- You need to install
- Nothing extra
- To build from source
- Rust
- Disk space
- 14 MB–42 MB · from the installer
- Accounts or keys
- Microsoft account that owns Minecraft: Java Edition
- Cost
- Free · Horizon itself is free and MIT-licensed, but it is not a free way to get Minecraft. The README says "Horizon contains no Minecraft code, assets or data: you need your own copy of Java Edition 26.3", and you need "a Microsoft account that owns Java Edition".
- License
- MIT (Permissive)
- Last update
- Nov 1, 2026
Risk signals (7)
- Highchecked against decompiled game code
Horizon is a rewrite of someone else's game, written against decompiled code. README, first lines: "Not an official Minecraft product, nor approved by or associated with Mojang or Microsoft. Horizon contains no Minecraft code, assets or data: you need your own copy of Java Edition 26.3." Cargo.toml says how the code is written: "Ports mirror vanilla's Java signatures, index loops and nested generic types one to one so they can be checked against the decompiled sources." Those inputs are kept off the repository: README, Build from source, "Prepared files land in the gitignored `.local/`: never commit or share them." and README, Contributing, "Never commit game files, decompiled source or prepared resources." The rule involved is named in the project's own Licence section: "Minecraft is a trademark of Mojang Synergies AB; its code and assets belong to Mojang and Microsoft under the [Minecraft EULA]".
AI review
- AttentionVery new repository with many stars
5388 stars in 28 days
automatic check
- AttentionOwner account created recently
Owner account created 4 days ago
automatic check
- Attentionsigns in with your microsoft account and joins online servers
README, Download: "You need a Microsoft account that owns Java Edition", and when you have no existing install, "Play downloads 26.3 from Mojang for your account". The Multiplayer line is "invite friends with a code, Open to LAN, join servers (online mode included)". So a client that is not the official one signs in with your game account and joins online-mode servers with it.
AI review
- Infoparity figure is the projects own audit
The 100% parity badge is the project's own measurement. README, Project status: "The table is the project's own audit: every subsystem matches vanilla in every harness that compares it. 100% means 100% of what the harnesses compare, not that nothing else differs." The same section opens with "Player-visible gaps: 833 open", the audit line reads "Last audited 2026-10-13: all 281 harnesses pass on Linux and macOS", and the top of the README says "more than 300 differential harnesses". Known issues listed: "Skins served over https show the default skin unless already cached; pack icons show the unknown-pack texture in game; item tooltips lack attribute lines."
AI review
- Infobrand new project releasing several times a day
The repository was created on 2026-10-03 and already has 294 releases and 344 open issues. The three latest releases are all dated 2026-10-31: launcher@0.2.31, launcher@0.2.30 and nightly-2026-10-31. The deterministic checks add 5388 stars in 28 days and an owner account created 4 days ago.
AI review
- Infoships a tool for ai agents to play as a player
README, Agent control: "AI agents and scripts can play Horizon. `horizon-ctl`, shipped with the game, reads its state as JSON and acts like a player; `horizon-ctl mcp` serves the same commands over MCP." The listed commands walk, mine and click inventory slots. The workspace also contains crates/horizon-bots and crates/horizon-anticheat.
AI review
Evidence is shown in its original language.
What Radar could not check
- Whether it behaves like the Java game in everything the harnesses do not compare: the audit covers 281 harnesses and the status page still lists 833 player-visible gaps.
- How it performs on a given graphics card, and whether the Intel driver crash the Cargo.toml comment describes is really gone.
- Whether the servers you play on accept a client that is not the official one, and what that means for your account.
- What the launcher does with your Microsoft sign-in and where it keeps the token.
- Real disk use once the game files, the JDK and the prepared resources are on your machine.
- Whether Mojang or Microsoft will take a position on the project.