If you have been following AI news lately, you may have seen a new arrival on OpenRouter. Space Bunny Alpha, released quietly as a "stealth" model, is getting a lot of attention. Thanks to its fast performance, huge context window, and free access, it is quickly becoming a go-to tool for developers and AI fans.
But aside from its performance, everyone is asking the same question: who made it?
Here is what we know about this anonymous model, the hints about its origins, and why stealth releases are now common in the AI world.
The Mid-Autumn Clue
Since Space Bunny Alpha appeared as an unbranded stealth model, OpenRouter has not shared who made it. Still, the timing gives us some clues.
The model appeared around the Mid-Autumn Festival. In Chinese folklore, this festival is closely linked to Chang'e, the moon goddess, and the Jade Rabbit who makes the elixir of immortality on the moon. Naming a stealth model "Space Bunny" during this holiday is a clear cultural reference, suggesting it comes from a leading Chinese AI lab.
Early testers have found technical clues that support this idea. The way the model handles tokenization and its API behavior closely match those seen in top Chinese labs, especially MiniMax. Its benchmarks also compete directly with models like DeepSeek Flash and GLM Flash.
The Stealth Playbook: Following the Footsteps of GLM Flash
At first, an anonymous release on OpenRouter might seem odd, but it actually follows a common strategy.
Major labs have used this approach before, such as Zhipu AI with its GLM Flash series and other top models. Before the official launch, labs often release preview versions with mysterious code names, usually offering them for free on platforms like OpenRouter and LMSYS Chatbot Arena.
Labs have three main reasons for doing this:
- Unbiased Real-World Evaluation: Releasing a model anonymously removes brand bias. Developers judge the results based only on performance, not reputation.
- Stress-Testing at Zero Cost: Making the model free brings in lots of users right away. This acts as an open beta, letting labs test their systems and see how the model handles real-world use.
- Viral Community Marketing: Stealth releases turn model launches into a group mystery. By the time the official announcement comes, the community already knows what the model can do.
Space Bunny Alpha is executing this exact playbook to perfection.
Specs and Performance: Flash Speed, Flagship Muscle
Even though it has a playful name, Space Bunny Alpha is built for serious production tasks:
- 1 Million Token Context Window: It can process entire repositories, large codebases, or several complex technical documents in one prompt.
- Extended Completion Output: It supports a very high output limit, so you can generate code across multiple files or draft long documents without breaking them up.
- Configurable Reasoning Effort: Space Bunny lets developers adjust how deeply it thinks, from quick checks to detailed step-by-step analysis.
- Native Multimodal Input: It can take in images and video as well as text, and works well for turning UI designs into code or for visual debugging.
- Free Tier Access: Right now, it is free to use on OpenRouter during the alpha preview.
Where It Excels (And What to Watch For)
Community tests show that this model performs much better than most "flash" tier models:
- Repository-Scale Code Audits: With its 1M context and adjustable reasoning, it tracks dependencies across modules, finds architectural bugs, and creates migration plans.
- Dense Document Extraction: It manages long documents well and can easily find conflicting clauses or regulatory requirements in several contracts.
- UI-to-Component Generation: If you give it app wireframes or recorded interface flows, it produces organized, clean front-end code with very few mistakes.
One thing to note: Like other fast models, it sometimes struggles with complex spatial calculations on the first attempt, such as making detailed SVGs or 3D coordinates. Usually, letting it try again fixes the problem.
Seeing It in Action: 3D HTML Generation
To test its spatial-coding ability, I recently used Space Bunny Alpha to create an interactive 3D environment with HTML and JavaScript.
The result was a procedural 3D planet generator that runs smoothly in the browser. The model handled the logic for building a scene where users can click and drag to rotate the sphere, and scroll to zoom in and out.
You can see the live demo here: Space Bunny 3D Planet Demo
Final Takeaway
Space Bunny Alpha stands out compared to other lightweight models. It offers deeper reasoning and a 1M context window, all for free.
If you want to do in-depth code reviews, test long-context retrieval, or try out one of the best anonymous models this year, use the free preview on OpenRouter. As with any early release, do not send sensitive information, but feel free to challenge it with your hardest tasks.
