Gemini 4 Carbon API Is Live: Model ID, Price, Benchmarks and How It Differs From Argon

Short answer

Google released Gemini 4 Carbon on October 28, 2026, calling it its strongest model, with a focus on cybersecurity and long-running tasks. Since November 10 it is generally available in the Gemini API, and it is live on Moyi API. The model ID is gemini-4-carbon; with a Moyi API key you call it the same way as any other model, with no Google account. The introductory price matches Gemini 4 Argon: $2 per million input tokens and $10 per million output tokens through November 30, 2026, with cached input 95% off the input price, rising to $4 / $20 after that. The Moyi API price is on the Gemini 4 Carbon page.

Gemini 4 Carbon is live: get an API key and call gemini-4-carbon now

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.

What Google announced

Everything below is from Google's post Gemini 4 Carbon: our next frontier model (October 28, 2026).

• Overall: #1 on version 5.0 of the Artificial Analysis Intelligence Index, with a score of 59.
• Cybersecurity (Google notes these were evaluated without guardrails):
  • Finding vulnerabilities: 88.2% on SEC-bench Pro
  • Checking whether they are exploitable: 54.8% on ExploitGym
  • Patching them: 71.0% on CWE-bench
  • On Google's internal benchmarks, more than 2x the success rate of Argon at generating secure code.
• Coding and long tasks: Google says its teams have seen Carbon run for days on multi-step engineering work such as finding and patching subtle bugs across large codebases. For web development it gained 89 Elo points to reach #4 (1768) on WebDev Arena.
• Reliability:
  • Successful cheating on Terminal-Bench 4.0 dropped to 0.0%.
  • Unsupported claims fell by about half compared with Argon in internal testing.
  • Attack success rate on the indirect prompt injection (IPI) benchmark is 0.0%, versus 0.7% for Argon.

Release timeline

• October 28, 2026: Google announces Carbon and gives access to a subset of cyber defenders first.
• November 10, 2026: Gemini 4 Carbon becomes generally available in the Gemini API under the model ID gemini-4-carbon (Gemini API changelog).
• Cyber variant: gemini-4-carbon-cyber-permissive, a version for defensive security work, stays behind an allowlist through Google's Fairwind Program. The regular gemini-4-carbon has no such restriction.

Pricing

Google's list price per 1 million tokens, in USD:

The introductory price is the same as Gemini 4 Argon's and runs through November 30, 2026, according to the Gemini API changelog. On Moyi API you pay per token from your balance; the current price is on the Gemini 4 Carbon page.

How Carbon differs from Argon

Google says Carbon builds on Argon and keeps its layered safety stack, with the biggest gains in cybersecurity and in how it handles ambiguous or high-pressure tasks: fewer shortcuts, less fabrication, and raising discrepancies with the user before acting.

Did the leak hold up?

On October 9, Business Insider reported that Google employees were testing a Gemini 4 build called Carbon on Jetski, Google's internal coding platform, and one employee said its coding felt comparable to Claude Opus 5.5. Carbon has now shipped under its own name rather than as an Argon update. Google's launch post does not compare it with Opus 5.5 directly.

Call Gemini 4 Carbon on Moyi API

Same key and base URL as every other 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-carbon",
    messages=[{"role": "user", "content": "Refactor this function to remove the nested loops: ..."}],
)
print(resp.choices[0].message.content)

To use Gemini 4 Argon instead, change model to gemini-4-argon. The Gemini-native request format works the same way as for Argon, with gemini-4-carbon as the model name: see Gemini 4 Argon API.

Paying for usage

No subscription: you top up a balance from $5 and pay only for the tokens you use, by card. The same key works for Gemini, Claude and GPT. If you are weighing a Claude plan instead, see Claude Pro and Max subscriptions vs paying per token.

FAQ

Is Gemini 4 Carbon out? Yes. Google announced it on October 28, 2026, and made it generally available in the Gemini API on November 10.

Can I call Gemini 4 Carbon through the API? Yes. The model ID is gemini-4-carbon, and it works through Moyi API with the OpenAI-compatible or Gemini-native format.

How much does Gemini 4 Carbon cost? $2 per million input tokens and $10 per million output tokens through November 30, 2026, with cached input 95% off; $4 / $20 after that.

What does Carbon do better than Argon? According to Google: cybersecurity (finding, validating and patching vulnerabilities), long-running coding tasks and reliability. The introductory price is the same.

Is Carbon on Moyi API? Yes, under Google's own model ID gemini-4-carbon. Use the same key as for Gemini 4 Argon and change only the model name.

Related

• Gemini 4 Carbon model page: current Moyi API price
• Gemini 4 Argon API: model ID, pricing and request examples
• Claude Opus 5.5 API: the model the leak compared Carbon to
• Gemini 4 Hydrogen API is out: the cheaper, faster tier of the same generation, released November 12
• Gemini Krypton release date: what we know: a newer Gemini checkpoint seen only in leaks, said to beat Carbon, not officially confirmed