OpenAImodelGPT-5.6 in the API (Generally Available)
The GPT-5.6 family from OpenAI is out of limited preview and open to all API developers in three tiers.
Details
- Sol is the flagship tier, strongest at coding, knowledge work, cybersecurity, and science
- Terra matches GPT-5.5 performance at lower cost, and Luna is the fastest and cheapest tier for high-volume tasks
- Per million input and output tokens: Sol costs $5 and $30, Terra costs $2.50 and $15, Luna costs $1 and $6
- The number marks the model generation, while Sol, Terra, and Luna mark capability tiers that can each advance on their own schedule
- The same models now sit behind ChatGPT and Codex, not only the API
Best for
Matching a price and speed tier to each task instead of routing everything through one flagship model.
When to use it
You are picking a model for production and want cost to track how hard the task actually is.
Who benefits
Developers and technical marketers building on the OpenAI API.
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