Zinc and Magnesium turn up disabled in DesignArena — and they expose a hole in our own detection

Two element codenames, Zinc and Magnesium, appeared in DesignArena. Both are disabled, which is what an entry looks like while it is still being tested rather than served.

This traces to a specific post: developer Pankaj Kumar flagged both models on X on July 28, reading them as likely updates to GPT-5.6 Sol and GPT-5.6 Terra respectively, and framing the timing as a response to Claude Opus 5. The circulating version of the claim adds that Zinc is an upgraded Sol, that Magnesium replaces or improves Terra, that they could launch before GPT-6, and that a public rollout could come this week or next.

There is no official confirmation of what either codename represents. OpenAI has said nothing, and a disabled entry in an arena tells you a model is being prepared, not what it is or when it ships.

The reason we are treating this as more than noise is that it fits a gap in our own detection. Our board tracks gpt-5-6 as live, which means the hunt on that family is disarmed — a new id like "gpt-5.6-sol-2" would land in a catalog and fire nothing, because as far as the pattern is concerned the family already dropped. A codename is what a staging catalog surfaces first, so we have armed Zinc and Magnesium as their own entry. If either name appears in a real catalog, that fires.

Worth holding the timeline in view. OpenAI is reported to be polishing the 5.6 family while Astra continues development and GPT-6 slips toward September. Two upgraded 5.6 tiers arriving before the flagship is consistent with that, and it is also consistent with nothing happening at all — the arena has carried disabled entries that never shipped before.

Grade: rumor. Named observer, dated post, no confirmation, and the sighting itself is a week old at time of writing.

WE CHECKED DESIGNARENA OURSELVES (2026-08-04). Here is exactly what is in its live registry API, because the answer is more interesting than the leak.

Both names are real. `zinc` and `magnesium` are present right now, as {"displayName": "zinc", "logoName": "private.png"} and the same for magnesium. That part of the claim is confirmed, and we confirmed it by reading the registry rather than by finding someone who said so.

Three things the leak leaves out.

They are in the PROVIDERS map, not the models map. DesignArena's registry has 455 model entries, 288 providers and 366 pricing rows. Neither zinc nor magnesium appears among the 455 models, and no model record references either name. A model record carries an id, a provider, an `active` flag and a list of arenas; these two carry a display name and a placeholder logo. So "both are currently disabled" is not quite what the data shows — there is no model entry there to disable.

They are two of 161. That is how many providers in that registry use `private.png`, the marker for an undisclosed provider. The list includes alpha_centauri, andromeda, honeycomb, obsidian, immortal, superstar, magnolia_2k, sora, zenith_alpha and 150-odd more. Anonymous codenames are not a rare event in DesignArena; they are a standing feature of it. Two more appearing is a weaker signal than "two new models have surfaced" makes it sound.

And nothing in the registry attributes either name to OpenAI. That is by construction — a private provider is private. Named providers carry a real record (openai has a website field and a logo file); these do not. The Sol-and-Terra reading is the leaker's inference, and it may well be right, but DesignArena is not the thing that supports it.

Revised grade: the EXISTENCE of both entries is confirmed, by us, from the source. The attribution to OpenAI, the "upgraded Sol / replacement Terra" mapping, and the this-week-or-next timing all remain rumor. We are leaving the item's grade at rumor because the parts that would matter to you are the unconfirmed ones.

The armed watch entry stays. If either codename shows up attached to an actual model record, that fires.