Cats Blender Plugin has left GitHub, and this repository is only the signpost

The repository you are looking at is a notice, not a product

The README on GitHub opens with a notice that the project has moved, and it is worth reading literally rather than skimming.

It states that this GitHub repository is no longer maintained. Cats Blender Plugin has not been discontinued, but all development, maintenance, updates, releases and support have permanently moved to a self-hosted NeoNeko Forgejo instance. The consequences are listed explicitly: GitHub is no longer maintained, GitHub issues and pull requests are no longer monitored and should not be used, and the code and releases on GitHub are outdated and should not be used for new installations.

The top level of the tree confirms it. There are only four entries, a .gitignore, a .gitmodules, the LICENSE and the README. The source code is not in this repository any more.

There is also a social instruction, which is unusual in a README. This version is an unofficial continuation and is not maintained by the original Cats development team, and readers are asked not to request assistance with it in the original Cats Discord server, because the original developers and their community are not responsible for supporting the NeoNeko version. NeoNeko does not run an official Cats Discord server or a separate Cats website, so support goes through the Forgejo issue tracker.

For a user, the practical effect is simple. The GitHub URL in an old tutorial, forum post or video will get you a README that tells you to go to git.neoneko.org.

The last push to the repository was on 2026-10-13, so the notice itself is current.

The official links all point at Forgejo

The README provides a table of project links, and every row points at the same host, git.neoneko.org, under the NeoNeko organisation.

The official repository is the NeoNeko Forgejo instance, and alongside it there are separate links for the releases and downloads page, the issue tracker for bug reports and feature requests, the pull requests page for contributions, and the wiki for documentation. The project website is neoneko.org.

The split matters for anyone planning to contribute or to get help. Bug reports, feature requests and contributions are all handled through Forgejo, and the README asks you to provide as much information as possible when reporting an issue, including your Blender version, your Cats version and any relevant error messages. It also states that support requests submitted through the old GitHub repository will not be monitored or answered.

That is a coherent arrangement for a project that has outgrown its previous home, and it has one consequence for tooling. A workflow that clones from GitHub, or a CI job that polls the GitHub tags, will now fetch a repository with no code in it. The published tags here are also a historical record rather than a release channel.

The Forgejo instance is self-hosted, which is a deliberate choice by NeoNeko rather than a limitation, and it does mean the project depends on the availability of that one host.

What the plugin actually does for a VRChat avatar

Cats is a Blender add-on designed to simplify the process of importing, fixing, optimising and preparing 3D models for VRChat. It was originally developed by Absolute Quantum and later maintained by the community, and this continuation is maintained by NeoNeko, with ongoing work focused on compatibility with modern Blender versions, performance improvements, bug fixes and additional functionality.

The feature list is organised around the stages of an avatar pipeline.

Import and export covers MMD, VRM, FBX, Source Engine and other formats. The formats named in the overview are wider still, adding XNALara and XPS, Mixamo, Unreal Engine, DAZ and Poser, Blender Rigify, The Sims 2, MotionBuilder, Autodesk 3ds Max, glTF and GLB.

Model optimisation is where the plugin earns its place: combining materials, generating texture atlases with the built-in Texture Atlas Tool, merging bones, removing unnecessary geometry, optimising meshes and materials. The README's summary of the effect is that tasks which would otherwise take hours can often be completed in just a few operations.

Eye tracking is automated, with support for both SDK3 and legacy eye tracking workflows, plus help with eye bone setup. Visemes and lip sync are generated and configured automatically, producing the mouth shapes VRChat expects.

The armature tools merge armatures, attach meshes to existing rigs, repair and optimise bones, and simplify skeletal structures. The shape key tools repair and manage shape keys and assist with optimisation. On top of that there are model scaling tools, custom model creation, material cleanup, mesh repair and rig optimisation.

The plugin is a pipeline tool for a specific platform, and its value is measured in hours saved per avatar.

One release per Blender version, and the compatibility trap

The release tags are the part that will trip you up if you do not read carefully.

The three most recent are 5.0.2.3, 5.0.2.2 and 5.0.2.1, and each of their titles says in parentheses that it is only for Blender 5.0. The dates run from 2025-12-13 through 2026-01-24, and the last push to the GitHub repository was on 2026-10-13.

The version scheme therefore encodes the Blender version, not just a feature level. Current development focuses on Blender 5.x and newer compatible releases, and the README is explicit that not every Cats release supports every Blender version, so you must download the appropriate release for your installed version of Blender.

The warning about older versions is worth repeating in full. Older Blender versions may require earlier Cats releases, compatibility with older Blender versions is not guaranteed, and support for legacy releases may no longer be provided.

That is the shape of a Blender add-on project in general, because Blender's Python API changes between major versions and a plugin built for 4.x will often not load in 5.x. The consequence for a user is that you are always choosing between a plugin that works and a plugin that is current, and the release page plus the version support wiki on Forgejo are where that decision gets made.

The requirements section adds that you need a supported version of Blender matching your chosen Cats release, that Blender should come from the official Blender website, and that NumPy may be needed in certain cases.

Translation tools that call third party services

One feature group deserves attention because of what it does with your data.

The translation tools translate Japanese bone, shape key, material and object names into English, and they support multiple translation providers, including Google, DeepL, LibreTranslate and MyMemory, along with tools for managing model translations.

For a model imported from MMD, that is a genuinely useful capability, because Japanese rig and shape key names are close to unreadable to an artist who does not read Japanese, and the bone names have to be renamed correctly for a VRChat rig to work at all. Doing that by hand for a hundred bones is exactly the kind of task the plugin exists to remove.

The privacy consideration is direct. With Google, DeepL or MyMemory as the provider, the names of your bones, materials and shape keys are sent to a third party service to be translated. For a hobbyist avatar that is a non-issue. For commissioned work under a client confidentiality agreement, or for a studio with a policy about sending unreleased asset names to external APIs, it is a decision to make deliberately rather than by default. The LibreTranslate option exists in the list, and a self-hosted instance of it would keep the request inside your own network.

The README does not document which provider is the default, so that is a question to answer in the plugin's own settings rather than from the documentation.

The Texture Atlas Tool replaced an add-on dependency

The texture section describes what is probably the most consequential change in the plugin, and it is phrased as a removal.

Cats can generate texture atlases directly within itself, combine materials and textures to improve optimisation, support configurable atlas dimensions and tiling, and reduce material complexity without requiring the legacy Material Combiner add-on for supported workflows.

In practice, a VRChat avatar has a limit on how many materials it may use, and a model imported from any of the source formats typically arrives with far more than that, one material per texture. The fix is to bake the textures into a smaller number of atlases and remap the model onto them. Doing that in Blender by hand is slow and error prone, so the standard workflow used to involve a separate add-on, and the phrase for supported workflows is doing careful work. It tells you the built-in tool covers the common cases and that there is a boundary where the old tool is still needed.

The configurable atlas dimensions matter as much as the generation itself, because an atlas that is the wrong size for a particular mesh set wastes texture space or fails to fit, and VRChat's own texture budget applies to the result. Being able to set the dimensions and tiling per model is what makes the built-in tool usable in a real pipeline rather than a demo.

The rest of the optimisation set, merging bones, removing geometry, and the material cleanup and mesh repair tools, follows the same pattern of taking work that is tedious in Blender and reducing it to a few operations.

Licence, community and the limits of an unofficial continuation

The repository is GPL-3.0, which is the licence the original project used and the one that applies to the code in this repository. For a Blender add-on that people install into their own application, the GPL obligations are not usually a practical obstacle, but they do become relevant if you distribute a modified version.

The more significant issue is the split in the community. The original Cats development team and its Discord server are not responsible for this continuation, and the README is explicit that support for the NeoNeko version will not be provided there. Meanwhile the original project still exists in its own right, and the two are not the same thing.

For someone who just wants a working plugin, the practical questions are short. Which Forgejo release matches your Blender version, does the version support wiki still cover the version you have, and can you get an answer when something breaks.

The plugin is also not a general purpose Blender tool. Everything in the feature list is oriented towards a VRChat avatar pipeline, with the platform's material limits, its eye tracking and viseme requirements, and its performance budget in mind. For a game asset pipeline outside VRChat, the tool would need work that nobody has committed to doing.

The one thing the documentation is unambiguous about is where to go. Not to GitHub.

Editorial conclusion

Cats Blender Plugin fits a VRChat avatar artist who imports models from MMD, VRM, DAZ, Mixamo or Source Engine and wants the rigging, eye tracking, viseme and optimisation work done in a few operations rather than a day of manual cleanup. It is not the repository to point a build at, because the GitHub copy no longer carries the code or the releases. Before you install anything, pick the release that matches your Blender version from the Forgejo releases page, since the numbering is tied to Blender releases, and treat the translation tools with care, because they send Japanese names to third party translation services.

Frequently asked questions

Official sources

1. License: GPL-3.0
2. Project website
3. README
4. Releases
5. teamneoneko/Cats-Blender-Plugin on GitHub