Rumor: Carbon is the next checkpoint after Argon
A leak claims Gemini 4 Argon is only the public release name, while the next internal checkpoint, Carbon, is already in Google coding tools and reportedly near Claude Opus 5.5 and GPT-6 Astra, with no public ID or API.
Google has not given you Argon yet. Testers are already talking about Carbon: Internal chatter says Carbon is the next checkpoint - already in Google coding tools, already used on real tickets. Some takes put it near Claude Opus 5.5 and GPT-6 Astra on software work. Argon was the announce. Carbon is the one they are supposedly climbing now. No public id. No Ultra toggle. No API you can pin. If your feed treats Carbon like a drop, it is still a leak with confidence. Wait for the name in the picker twice. Until then Carbon is a rumor you can watch, not a model you can install.
This post quotes another post: x.com/merliiin__/status/2108124305749913878