OpenAI launches GPT-5.6 in three tiers, with an agent for whole jobs

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On July 9, 2026, OpenAI opened its GPT-5.6 model family to the public across ChatGPT and its API, releasing three capability tiers named Sol, Terra, and Luna. Sol is the flagship; Terra is positioned as a balanced model for everyday work, described as competitive with the prior GPT-5.5 at roughly half the cost; and Luna is the fastest and lowest-cost tier.

The release introduces a revised naming scheme in which the generation number (5.6) marks the model version, while the names Sol, Terra, and Luna denote durable capability tiers that can advance on their own cadence. Published API pricing, per one million tokens, is $5 input / $30 output for Sol, $2.50 / $15 for Terra, and $1 / $6 for Luna.

Alongside the models, OpenAI introduced an agent it calls ChatGPT Work, built to carry out complete tasks rather than only answer individual questions. The broad public rollout on July 9 followed a limited preview that began June 26 for roughly 20 government-approved organizations, and, according to reporting, came after regulatory clearance from the U.S. Department of Commerce.

The GPT-5.6 launch arrived within a dense stretch of model releases in early July 2026, including public availability of competing frontier and open-weight systems from other labs.

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