OpenAI just moved the GPT-5.6 family to general availability, following a limited preview. The release ships three models rather than one. Sol is the flagship, Terra is the balanced everyday tier, and Luna is the most cost-efficient.
To sum up
GPT-5.6 ships three tiers — Sol, Terra, Luna — priced from $1/$6 to $5/$30 per 1M tokens.
Sol leads the Artificial Analysis Coding Agent Index at 80, 2.8 points above Claude Fable 5.
Programmatic Tool Calling runs model-written JavaScript in an isolated V8 runtime with no network access.
