Short answer
Google released Gemini 4 Hydrogen (gemini-4-hydrogen) on November 12, 2026, at $1.50 per million input tokens and $7.50 per million output, with a free tier. On capability per dollar it is currently the best-balanced Gemini 4 tier.
Two separate gates stand between you and the official endpoint:
- Network: the API lives at
generativelanguage.googleapis.com. Direct connections from mainland China do not reach it. - Account and payment: the official endpoint needs a Google account and a payment method Google accepts (the free tier does not need a card).
Neither gate has anything to do with the model. They are Google's rules for the Gemini API as a whole, and apply to every Gemini model — Hydrogen is not special here.
gemini-4-hydrogen is not on Moyi API yet. Once it lands, you will not need a Google account or a network path to Google — a Moyi API key is enough. Until then, the same-generation models you can use with one key are Gemini 4 Argon (gemini-4-argon) and Gemini 4 Carbon (gemini-4-carbon).
Why it is not directly usable from China
Google's available regions for the Gemini API and Google AI Studio does not list mainland China or Hong Kong. This is a blanket rule across all Gemini models, not a restriction on one SKU.
So the official route from China means: a Google account to get a key in AI Studio, a network path to Google, and a card Google accepts (not needed on the free tier).
For Russia: the endpoint is usually reachable at the network level, but Google's payment methods are restricted in Russia and binding a card often fails. The free tier needs no card, so it works for evaluating the model, but not for running production.
Three routes and what each costs you
| Route | Google account | Network path to Google | Google-accepted card | Moyi API key |
|---|---|---|---|---|
| Official, free tier | Yes | Yes | No | — |
| Official, paid tier | Yes | Yes | Yes | — |
| Moyi API (once listed) | No | No | No | Yes |
What you can use today
gemini-4-hydrogen has not entered our catalog, but its two siblings have, and they share the same architecture:
- Gemini 4 Argon (
gemini-4-argon): handles most long-horizon tasks with fewer tokens than Carbon. Intro price $2 / $10 through November 30, 2026, then $4 / $20. Good default for everyday coding and multi-step work. - Gemini 4 Carbon (
gemini-4-carbon): Google's strongest tier, built for hard reasoning, debugging and security audits. Same intro price as Argon.
Both use one key and one base URL, in either the OpenAI-compatible format or the native Gemini format. See Gemini 4 Argon API and Gemini 4 Carbon API.
How to call it once it lands
Nothing you already have changes — only model:
from openai import OpenAI
client = OpenAI(base_url="https://api.moyi-api.com/v1", api_key="YOUR_KEY")
resp = client.chat.completions.create(
model="gemini-4-hydrogen",
messages=[{"role": "user", "content": "Explain what a context window is in one sentence."}],
)
print(resp.choices[0].message.content)
gemini-4-hydrogen is not on Moyi API yet. Once it is live, the same key and model: gemini-4-hydrogen is all you change; until then, use gemini-4-argon.
Running it from Claude Code or Codex
Hydrogen runs on the standard generateContent path, exactly like Argon and Carbon. Any client that speaks the native Gemini format works once it is listed: point the base URL at https://api.moyi-api.com and set the model to gemini-4-hydrogen.
One thing to watch: for coding work, Hydrogen bills output tokens and thinking tokens together, so xhigh costs meaningfully more than high. Start at high (the default) and only step up when quality actually falls short.
How to pay
No subscription: top up your balance in the console from $5, billed by the tokens each request uses. Cards are supported. The same key also calls Claude and GPT models.
New accounts start with a $0 balance — top up before your first request. Top up from $5. If a request returns 402 (400 on the OpenAI format) with "wallet balance is insufficient", your balance is empty — your base URL and key are fine. Top up and retry.
FAQ
Can I use Gemini 4 Hydrogen directly from China?
No. Google's available-regions list excludes mainland China and Hong Kong, and the endpoint requires a network path to Google. The official route needs a Google account and that network path.
Does it work from Russia?
The endpoint is usually reachable at the network level, but Google's payment methods are restricted in Russia and card binding often fails on the paid tier. The free tier needs no card, so it works for evaluation.
Can I use it on Moyi API now?
Not yet — gemini-4-hydrogen has not entered our catalog. Once it does, no Google account and no network path to Google are needed: same key, new model ID.
What if I have no Google account?
Two options: wait for gemini-4-hydrogen to be listed on Moyi API and use our key, or use gemini-4-argon / gemini-4-carbon today — they are the same Gemini 4 generation and already available.
Does a third-party gateway need special configuration?
No. Hydrogen is a standard generateContent model, not a separate endpoint like Gemini Decision (/v1beta/decisions). Once listed, it is a model-name swap.
Related reading
- Gemini 4 Hydrogen API is out: price, the four thinking levels and how to call it
- Gemini 4 Hydrogen vs Carbon vs Argon: the comparison
- Gemini 4 Argon API: available on Moyi API today
- Gemini API available regions: Google's official list