ProbeJS in Minecraft: Smarter KubeJS Scripting for Modern Modpacks
If you have ever built a custom Minecraft modpack and tried to automate recipes with KubeJS, you know how quickly scripting can become messy. That is exactly where ProbeJS steps in. ProbeJS is a typing generator mod designed to improve your KubeJS workflow by generating declarations and snippets that unlock much better IntelliSense support in VSCode. Instead of guessing method names, block IDs, or event structures, you get guided suggestions while writing scripts for your world, server, or modpack.
For technical players who enjoy tweaking mechanics, balancing progression, and integrating mods across biomes and dimensions, this is a major quality-of-life upgrade. ProbeJS does not change vanilla gameplay directly, but it dramatically improves the development environment behind many custom Minecraft experiences.
What ProbeJS Actually Does
At its core, ProbeJS scans your Minecraft instance and generates typing files for KubeJS scripts. Those generated files help VSCode understand your scripting context, including items, blocks, fluids, and many modded systems. The result is cleaner code completion, better inline information, and fewer scripting mistakes.
In practical terms, that means:
- Auto-completion while editing KubeJS startup and server scripts
- Snippet support for quick insertion of common scripting patterns
- More reliable type hints for modded recipe and event APIs
- Improved readability when managing larger script sets in multiplayer servers
For anyone maintaining custom crafting trees or progression logic, these improvements can save hours of debugging per update cycle.
Key Changes in ProbeJS v7.0.0
The v7.0.0 release introduces a code generation rework. The most important workflow shift is that scripts now need to be placed in a src folder for type hinting support to work correctly, such as startup_scripts/src. This is a meaningful change for existing setups, so migrating folder structure should be one of your first steps when updating.
The author has indicated that this structure may be reverted in Minecraft 1.21, but for now, treating the src layout as required will avoid confusion and missing IntelliSense.
Another major compatibility point: ProbeJS focuses on newer versions and does not plan support for older releases. If your server is pinned to an outdated Minecraft version, this is important to consider before adopting it across your team.
Compatibility, IDE Focus, and Modding Workflow
ProbeJS supports both Forge and Fabric, which is excellent news for mixed communities. However, its generated snippets are specifically designed in VSCode style. Other IDEs may still read declaration files and offer partial completion, but the full feature set is strongly tied to VSCode behavior.
There is also a useful ecosystem feature in 1.20.1 and newer branches: ProbeJS can download predefined recipe support scripts from a public repository. This reduces the need for fallback wrappers like event.custom in many cases and creates cleaner, fully typed script logic. For heavily modded servers with hundreds of recipes and machine integrations, this can significantly improve maintainability.
Many modpack creators mention that this mod can be set up quickly through the foxygame.net launcher, a convenient, flexible, and modern Minecraft launcher with in-menu mod downloads. That streamlined install path is especially handy when you are syncing a shared development environment for multiple script contributors.
How to Use ProbeJS Effectively
The setup process is straightforward once you know the expected flow. Install the mod, run the dump command in-game, and then open the Minecraft instance folder in VSCode. You should find generated configuration and declaration files that drive completion and type docs.
- Install ProbeJS in your modded Minecraft instance
- Run /probejs dump in singleplayer
- Open the instance root folder in VSCode (parent of the kubejs folder)
- Verify generated typing files and VSCode project metadata
- Edit scripts under KubeJS and test snippets like @item or @block
If IntelliSense does not appear, check whether probe-prefixed JSON files exist in .vscode, confirm that .d.ts files were generated under KubeJS probe output, and ensure those declaration files are free of syntax errors. These checks usually identify the bottleneck quickly.
What About Item Rendering and Hover Details?
In newer versions, item and fluid rendering behavior tied to hover previews has changed, and some visual extras were stripped from ProbeJS itself. If you want item icons during hover interactions in tooling workflows, you may need a companion mod such as IconExporter. The important point is that ProbeJS remains useful even without those visual enhancements, because its typing and snippet value is still strong for actual script development.
Why ProbeJS Matters for Minecraft Servers and Pack Teams
When a server runs dozens or even hundreds of mods, scripting consistency becomes a real performance and maintenance issue. Poorly structured KubeJS files can break progression, introduce recipe loops, or create biome progression exploits. ProbeJS helps reduce those risks by giving creators better guardrails while coding.
It also supports collaborative work: one person can tune crafting chains, another can handle block interaction mechanics, and another can manage cross-mod compatibility, all with clearer suggestions and less guesswork. For long-term modpacks that evolve across Minecraft updates, that is a major advantage.
Final Thoughts
ProbeJS is one of those behind-the-scenes Minecraft mods that quietly transforms how advanced content gets built. It does not add flashy mobs or new biomes directly, but it improves the foundation that many custom packs depend on: reliable KubeJS scripting. With modern version support, Forge and Fabric compatibility, and practical type generation for VSCode, it is a powerful tool for anyone serious about modded Minecraft development.
If you are building or maintaining scripted gameplay systems, ProbeJS is worth integrating early in your workflow. Better hints, stronger completion, and cleaner script architecture lead to fewer errors and faster iteration across updates, versions, and server deployments.
--- **Update May 11, 2026:** Added 1 file for version 1.21.1 (NeoForge). --- **Update May 17, 2026:** Added 1 file for version 1.21.1 (NeoForge). --- **Update May 21, 2026:** Added 1 file for version 1.21.1 (NeoForge). --- **Update Aug 26, 2026:** Added 1 file for version 1.21.1 (NeoForge).