An anonymous model listed as stealth/space-bunny-alpha on OpenRouter since September 23 has quietly become the most-used model on the platform, logging a reported 5.2 trillion tokens on October 1 — more than GPT-6 Astra on its busiest day. It is also available via OpenCode Zen as space-bunny-free and through BeatAPI. No company has claimed it.

Independent testing describes a capable model: 1M-token context, up to 524K output tokens, adjustable reasoning effort, tool calling, and image and video input. Third-party evals found it shipping working Three.js scenes, finding needles in 91K-token documents, and holding its own on coding tasks — though it reportedly never checks its own output.

The strongest clue yet points at MiniMax. Two independent tokenizer studies — one matching all 50 test strings to eight tested MiniMax models — put Space Bunny in the MiniMax family, and MiniMax quietly shipped an M3.1-Flash-Preview inside its MiniMax Code product on September 27 without connecting it to the bunny. But the developer remains officially anonymous, the free preview has no published end date, and OpenRouter notes the provider may retain prompts. Fingerprint similarity is not confirmation — the rumor stays unresolved.

Update, October 5: the preview ended. SpaceBunny's FAQ records that the OpenRouter route (stealth/space-bunny-alpha, listed September 23) was withdrawn on October 5, 2026 — an October 6 check found no available endpoints and returned 404. The maker was never officially confirmed; the strongest fingerprint evidence still points at MiniMax's M3.1-Flash-Preview, but MiniMax never confirmed the link. The underlying claim — that an anonymous free model quietly topped OpenRouter's usage charts — was verified by multiple trackers while it lasted.