Post says the model responded on Vertex AI's API
A post saying that "Gemini 4 Hydrogen," described as an unannounced Google AI model, responded on the API of Vertex AI, the company's cloud development platform, appeared on X at 3:07:57 p.m. Nov. 12 Japan time. It was posted by @aitrackerbot (AI Tracker Bot), an account that describes itself as automatically tracking AI model releases. According to the account, when it called the model name "gemini-4-hydrogen" on Vertex AI's global endpoint (an address that does not specify a region), it received a "200" response, the code that indicates success. The account said the model answered "I am Gemini 4 Hydrogen, a large language model built by Google." and that the response's model version field also said "gemini-4-hydrogen." ORIENS has not tried the call and has not been able to confirm the contents of the post.
🚨 Gemini 4 Hydrogen has returned 200 on Google Vertex API We called gemini-4-hydrogen on Vertex AI's global endpoint. It answered "I am Gemini 4 Hydrogen, a large language model built by Google." and the response's model version field says gemini-4-hydrogen. It isn't in Google's Vertex model catalog yet, and Google hasn't announced it.
Name absent from official model lists and changelogs
The post itself says the model is not yet in Vertex AI's model catalog and that Google has not announced it.
When ORIENS checked on Nov. 12 Japan time, neither Hydrogen nor gemini-4-hydrogen appeared in the list of Google models in Google Cloud's developer documentation. The URL of Vertex AI's model list now redirects to a page in the "Gemini Enterprise Agent Platform" documentation. There is also no mention in that platform's release notes through Nov. 11, or in the Gemini API's model list and its changelog through Nov. 11.
A report that a response came back is not enough to judge whether general developers can use the model or when it will be released. No official information has been released on the timing of a release or who it would be offered to.
A further leak after reports of testing on AI Studio and Arena
On Nov. 5, ORIENS reported a leaker's claim that Hydrogen was being A/B tested (a trial that shows a different version to only some users and compares them) in the developer environment "Google AI Studio" and on "Arena," a site that compares AI answers anonymously. In that report, Hydrogen was described as the code name of the unannounced "Gemini 4 Flash." The view that Hydrogen corresponds to Gemini 4 Flash comes from posts by individuals since late October; no evidence has been offered, and Google has not confirmed it.
The latest post says the model identified itself as "Gemini 4 Hydrogen" and does not mention the Flash name. There are also no official materials showing Hydrogen's performance, pricing or release date.
Addendum: On Nov. 13, Google officially released the model (Google: Introducing Gemini 4 Hydrogen).
- Post says Gemini 4 Flash's code name is "Hydrogen"Rumor
- Post says Hydrogen is in A/B testing on AI Studio and ArenaLeak
- @aitrackerbot posts that it responded on Vertex AI's APILeak
