OpenAI says GPT-5.6 is entering limited preview as a three-model family called Sol, Terra and Luna, with published per-token pricing tiers and a system card describing preview safety and capability evaluations.
OpenAI says it has begun a limited preview of GPT-5.6 Sol, Terra and Luna for API and Codex users, according to an OpenAI Help Center article and a company announcement.
OpenAI describes GPT-5.6 as a three-model family: Sol, Terra and Luna. In its announcement, “Previewing GPT-5.6 Sol: a next-generation model,” OpenAI says Sol is the flagship model, while Terra and Luna are positioned around lower cost and speed.
The OpenAI Help Center article, “A preview of GPT-5.6 Sol, Terra, and Luna,” says the models are available in limited preview for API and Codex. The wording indicates this is not a general release, and OpenAI’s own materials frame the launch as a preview deployment rather than broad availability.
The Help Center article lists per-1-million-token pricing for the three models. OpenAI gives GPT-5.6 Sol pricing as $5/$30, GPT-5.6 Terra as $2.50/$15, and GPT-5.6 Luna as $1/$6. The same Help Center source also says OpenAI has updated prompt-caching rules for the preview models.
Those prices put Luna at the lowest listed tier, Terra in the middle, and Sol at the highest listed tier. OpenAI’s own announcement is consistent with that positioning, describing Sol as the flagship model and Terra and Luna as options oriented toward cost and speed.
OpenAI also published a “GPT-5.6 Preview System Card,” according to the source document hosted by OpenAI’s deployment safety site. The system card describes GPT-5.6 as a family of three models — Sol, Terra and Luna — and covers safety and capability evaluations for the preview deployment.
The available source excerpts do not provide enough detail to compare GPT-5.6’s benchmark performance with prior OpenAI models or competitors. They also do not specify how many users or developers have access during the limited preview. For now, the clearest confirmed details are the model names, the limited-preview status, availability through API and Codex, the published pricing tiers, and the existence of accompanying safety documentation.
For developers, the practical significance is that OpenAI is presenting GPT-5.6 as a tiered family rather than a single model. Based on OpenAI’s announcement and Help Center description, Sol is the premium option, while Terra and Luna are intended to offer lower-cost or faster alternatives.
Because OpenAI labels the release as a limited preview, production use may depend on access, preview terms and model behavior that could change before wider release. Developers evaluating the models should rely on OpenAI’s Help Center, the company announcement and the GPT-5.6 Preview System Card for current deployment, pricing and safety information.
OpenAI says it has begun a limited preview of GPT 5.6 Sol, Terra and Luna for API and Codex users, according to an OpenAI Help Center article and a company announcement.
Three models in preview OpenAI describes GPT 5.6 as a three model family: Sol, Terra and Luna.
In its announcement, “Previewing GPT 5.6 Sol: a next generation model,” OpenAI says Sol is the flagship model, while Terra and Luna are positioned around lower cost and speed.
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