GPT-5.6 Is Now Available in Tukun.ai: Luna, Terra, and Sol

Tukun.ai now supports the GPT-5.6 model family.

The workbench now includes GPT-5.6 Luna, GPT-5.6 Terra, and GPT-5.6 Sol. These models are available through the plan-scoped catalog, so the choices visible in the selector depend on the account’s active plan.

The GPT-5.6 lineup

• GPT-5.6 Luna is available on Free, Pro, and Max as a lighter entry-level option.
• GPT-5.6 Terra is available on Pro and Max for paid-plan work and analysis.
• GPT-5.6 Sol is available on Max as an additional option in the widest current catalog.

Every plan now has a GPT-5.6 path, without turning the model selector into an open-ended provider marketplace.

Availability by plan

These entries sit alongside the other models available to each plan. The selector shows only models that the current account is entitled to use.

Choosing a model in the workbench

Choose a named GPT-5.6 model when you want to make the model choice explicit for a conversation or analysis task. The workbench always keeps that choice inside the account’s plan boundary.

Pro and Max accounts can also use Auto. Auto is server-side routing, not a promise that every turn uses the strongest listed model. It starts from the plan’s default behavior and moves to a stronger eligible model only when the request calls for it.

Free remains a concrete-model experience: Auto is not available as an account model selection on that plan.

A catalog that can evolve

Models can be added, upgraded, or retired as providers evolve. Tukun.ai keeps the durable product contract at the plan level:

• Free provides an entry-level, plan-scoped model catalog.
• Pro adds paid-model access and Auto for reasoning or heavier analysis.
• Max provides the widest current catalog, including GPT-5.6 Sol.

That lets the model lineup evolve while keeping access understandable where it matters: the workbench and the plan a customer has chosen.

For the full current model list, see the models by plan documentation.