Code-name archive
Stealth Models: Which AI Models Hid Behind Code Names
- code names
- 33
- officially revealed
- 22
- still open
- 5
- days to reveal (median)
- 7
All stealth models and what was behind them
- Crouton Alphastill openstealth/crouton-alphaPlatform: OpenRouterPeriod: first seen Nov 3, 2026not known yet
Still available on 7 November 2026; according to OpenRouter the developer remains anonymous for now.
still openLaunch - Space Bunny Alphaofficially confirmedstealth/space-bunny-alphaPlatform: OpenRouterPeriod: first seen Sep 23, 2026revealed in October 2026MiniMax M3.1 FlashMiniMax
- Union Alphaofficially confirmedstealth/union-alphaPlatform: OpenRouterPeriod: first seen Sep 16, 2026ParetoUnbiased
Pareto is a system of several models, not a single model.
- Ox Alphaofficially confirmedstealth/ox-alphaPlatform: OpenRouterPeriod: first seen Aug 20, 2026revealed on Aug 26, 2026GLM-5.3-FlashZ.ai
- Owl Alphareportedopenrouter/owl-alphaPlatform: OpenRouterPeriod: first seen Apr 28, 2026revealed on Jun 30, 2026LongCat 2.0Meituan
Reports tie Owl Alpha to LongCat-2.0; neither Meituan nor OpenRouter has confirmed it explicitly.
- Elephant Alphaofficially confirmedopenrouter/elephant-alphaPlatform: OpenRouter, Kilo CodePeriod: first seen Apr 13, 2026revealed on Apr 21, 2026Ling-2.6-flashAnt Group
In Kilo Code it briefly ran as “Elephant”.
- HappyHorse-1.0reportedPlatform: Artificial AnalysisPeriod: first seen Apr 7, 2026revealed on Apr 10, 2026HappyHorse 1.0Alibaba
Submitted without a developer; reports tie it to Alibaba, the official launch followed on 27 April 2026.
- maskingtape-alphareportedmaskingtape-alpha, gaffertape-alpha, packingtape-alphaPlatform: LMArenaPeriod: first seen Apr 4, 2026revealed on Apr 22, 2026GPT Image 2OpenAI
Three variants (maskingtape, gaffertape, packingtape). The GPT Image 2 attribution comes from reports.
- Healer Alphaofficially confirmedopenrouter/healer-alphaPlatform: OpenRouterPeriod: first seen Mar 11, 2026revealed on Mar 18, 2026MiMo-V2-OmniXiaomi
- Hunter Alphaofficially confirmedopenrouter/hunter-alphaPlatform: OpenRouterPeriod: first seen Mar 11, 2026revealed on Mar 18, 2026MiMo-V2-ProXiaomi
- Aurora Alphastill openopenrouter/aurora-alphaPlatform: OpenRouterPeriod: first seen Feb 9, 2026not known yetstill openLaunch
- Pony Alphaofficially confirmedopenrouter/pony-alphaPlatform: OpenRouterPeriod: first seen Feb 6, 2026revealed on Feb 11, 2026GLM-5Z.ai
- Giga Potatostill opengiga-potato:freePlatform: Kilo CodePeriod: first seen Jan 16, 2026not known yet
Kilo Code only named a “top OSS lab”.
still openLaunch - Bert-Nebulon Alphaofficially confirmedopenrouter/bert-nebulon-alphaPlatform: OpenRouterPeriod: first seen Nov 24, 2025revealed on Dec 2, 2025Mistral Large 3Mistral AI
- Sherlock Dash Alphaofficially confirmedopenrouter/sherlock-dash-alphaPlatform: OpenRouterPeriod: first seen Nov 15, 2025Grok 4.1 FastxAI
Early snapshot of Grok 4.1 Fast with reasoning off.
officially confirmedReveal - Sherlock Think Alphaofficially confirmedopenrouter/sherlock-think-alphaPlatform: OpenRouterPeriod: first seen Nov 15, 2025Grok 4.1 FastxAI
Early snapshot of Grok 4.1 Fast with reasoning on.
officially confirmedReveal - Polaris Alphaofficially confirmedopenrouter/polaris-alphaPlatform: OpenRouterPeriod: first seen Nov 6, 2025revealed on Nov 13, 2025GPT-5.1OpenAI
Early snapshot of GPT-5.1 with minimal reasoning effort.
- Andromeda Alphaofficially confirmedopenrouter/andromeda-alphaPlatform: OpenRouterPeriod: first seen Oct 21, 2025Nemotron Nano 2 VL 12BNVIDIAofficially confirmedReveal
- Code Supernovastill openPlatform: Cline, Kilo CodePeriod: Sep 19, 2025 to Oct 27, 2025not known yetstill openLaunch
- Sonoma Dusk Alphaofficially confirmedopenrouter/sonoma-dusk-alphaPlatform: OpenRouterPeriod: first seen Sep 5, 2025revealed on Sep 19, 2025Grok 4 FastxAI
According to OpenRouter, an early test version of Grok 4 Fast.
- Sonoma Sky Alphaofficially confirmedopenrouter/sonoma-sky-alphaPlatform: OpenRouterPeriod: first seen Sep 5, 2025revealed on Sep 19, 2025Grok 4 FastxAI
According to OpenRouter, an early test version of Grok 4 Fast.
- Horizon Betareportedopenrouter/horizon-betaPlatform: OpenRouterPeriod: first seen Aug 1, 2025revealed on Aug 7, 2025GPT-5OpenAI
Improved version of Horizon Alpha. The GPT-5 attribution comes from reports.
- nano-bananaofficially confirmedPlatform: LMArenaPeriod: first seen August 2025revealed on Aug 26, 2025Nano Banana (Gemini 2.5 Flash Image)Google
The code name stuck as the official nickname “Nano Banana”.
- SonicreportedPlatform: Kilo Code, ClinePeriod: first seen August 2025revealed on Aug 26, 2025Grok Code Fast 1xAI
Kilo Code named Grok Code Fast as the model behind Sonic; there is no quote from xAI.
reportedReveal - Horizon Alphareportedopenrouter/horizon-alphaPlatform: OpenRouterPeriod: first seen Jul 30, 2025revealed on Aug 7, 2025GPT-5OpenAI
Reportedly an early GPT-5 checkpoint; OpenRouter's model page does not state it.
- Cypher Alphastill openopenrouter/cypher-alphaPlatform: OpenRouterPeriod: first seen Jul 1, 2025not known yet
OpenRouter listed “Cypher Labs” as the provider and called that name fictional itself.
still openLaunch - summitofficially confirmedPlatform: LMArenaPeriod: first seen July 2025revealed on Aug 7, 2025GPT-5OpenAI
LMArena confirmed at launch that GPT-5 had been tested as “summit”. The exact checkpoint is not known.
- Optimus Alphaofficially confirmedopenrouter/optimus-alphaPlatform: OpenRouterPeriod: Apr 10, 2025 to Apr 14, 2025revealed on Apr 14, 2025GPT-4.1OpenAI
Second test model of the full GPT-4.1, revealed together with Quasar Alpha.
- Quasar Alphaofficially confirmedopenrouter/quasar-alphaPlatform: OpenRouterPeriod: Apr 2, 2025 to Apr 14, 2025revealed on Apr 14, 2025GPT-4.1OpenAI
According to OpenRouter, a test model of the full GPT-4.1.
- chocolateofficially confirmedPlatform: LMArenaPeriod: first seen February 2025revealed on Feb 18, 2025Grok 3xAI
An early version of Grok 3.
- red_pandaofficially confirmedPlatform: Artificial AnalysisPeriod: first seen October 2024revealed on Oct 31, 2024Recraft V3Recraft
- blueberryofficially confirmedPlatform: Artificial AnalysisPeriod: first seen September 2024revealed on Oct 3, 2024FLUX1.1 [pro]Black Forest Labsofficially confirmedReveal
- gpt2-chatbotofficially confirmedgpt2-chatbot, im-a-good-gpt2-chatbot, im-also-a-good-gpt2-chatbotPlatform: LMArenaPeriod: first seen April 2024revealed on May 13, 2024GPT-4oOpenAI
Ran under three similar names in what was then Chatbot Arena; OpenAI confirmed GPT-4o at launch.
These code names are not revealed yet
OpenRouter, first seen Nov 3, 2026
Still available on 7 November 2026; according to OpenRouter the developer remains anonymous for now.
OpenRouter, first seen Feb 9, 2026
Kilo Code, first seen Jan 16, 2026
Kilo Code only named a “top OSS lab”.
Cline, Kilo Code, Sep 19, 2025 to Oct 27, 2025
OpenRouter, first seen Jul 1, 2025
OpenRouter listed “Cypher Labs” as the provider and called that name fictional itself.
Who tests in stealth most often
- OpenAI5 code names
- xAI5 code names
- Xiaomi2 code names
- Z.ai2 code names
- Ant Group1 code name
- Black Forest Labs1 code name
- Google1 code name
- MiniMax1 code name
- Mistral AI1 code name
- NVIDIA1 code name
- Recraft1 code name
- Unbiased1 code name
What is a stealth model?
A test under a false name
A stealth model is an unreleased AI model that a provider makes publicly usable under a code name. Users do not know who built it.
Why providers do it
The provider gets real usage data and honest feedback without the brand name colouring the verdict. In arenas, the code name also shows how the model does in blind comparisons.
How we match them
A code name counts as revealed here once the developer or the platform has named the model behind it. Guesses from tokenizer or benchmark comparisons do not count.
Frequently asked questions about stealth models
What is a stealth model?
A stealth model is an unreleased AI model that a provider lets people test under a code name, for example on OpenRouter or in LMArena. Only at the official launch does the provider reveal which model was behind it.
Which stealth model was revealed most recently?
The most recent reveal was Space Bunny Alpha on OpenRouter. It turned out to be MiniMax M3.1 Flash from MiniMax.
How long does a stealth model stay secret?
The median is 7 days from the first appearance to the official reveal, measured across 11 code names with exact dates.
Which provider tests under code names most often?
OpenAI and xAI lead with 5 officially revealed code names.
Which stealth models are not revealed yet?
Still open: Crouton Alpha, Aurora Alpha, Giga Potato, Code Supernova and Cypher Alpha. Neither the developer nor the platform has confirmed which model is behind them.