Image: Google

Google's Gemini 4 Argon has picked up a new "Contributor" pricing tier in Google's Gemini API billing, according to LuminaBench, an X account that tracks AI model leaks. Google hasn't announced the tier, and the listing hasn't been independently verified.

LuminaBench shared a screenshot of the listing. It shows Gemini 4 Argon Contributor priced at $2 per million input tokens, $0.10 per million cached input tokens and $10 per million output tokens. Tokens are the small chunks of text, images or video that AI models read and write, and API customers pay for them in bulk.

Gemini 4 Argon now has a contributor version

• $2 Input /1M
• $0.10 cached /1M
• $10.00 Output /1M

This is just half price i'm pretty sure pic.twitter.com/3WXeBD38Wg

— Lumina (@LuminaBench) October 13, 2026

The account called it "just half price", but added it wasn't fully sure. Its own screenshot is careful too: it says Contributor is a published billing tier, but that access to the model is unconfirmed.

Here's what the numbers line up with. When Google launched Gemini 4 Argon to trusted testers, it said the model would start at an introductory $2 per million input tokens and $10 per million output tokens, with cached input 95% off. Ninety-five percent off $2 is exactly $0.10. After the introductory period, Google said, the price rises to $4 and $20.

So the Contributor listing matches Google's launch-period price to the cent, and it is half of the later standard price. That points to one of two things. Contributor could be the name for the introductory deal, or it could be a separate tier that keeps the lower price after the intro period ends. Google hasn't said which.

Who counts as a "contributor" is also unclear. Google hasn't explained what users would need to do to get the tier, or whether it involves sharing data or feedback in return for the lower price.

The timing is worth watching. Shortly before the pricing post, LuminaBench said Gemini 4 Argon model IDs had appeared in Google's Antigravity desktop app and command-line tool, and that a wider rollout could be close. It also said the model might reach Google AI Ultra subscribers first.

For now, Gemini 4 Argon is still limited to trusted testers. If the Contributor tier is real, developers waiting on Argon may at least know what it will cost on day one.