OpenAI launched its GPT-5.6 family to general availability on July 9, 2026, ending a two-week limited preview period that began June 26. The rollout covers ChatGPT, Codex, and the OpenAI API simultaneously, with three tiers targeting different workloads and budgets.
Three Models
GPT-5.6 Sol is the flagship. Built for complex reasoning and long-horizon agentic tasks, it sets new benchmarks on Terminal-Bench 2.1, the agentic evaluation suite focused on multi-step computer tasks.
GPT-5.6 Terra is the practical workhorse. OpenAI positions it as GPT-5.5-competitive at roughly half the cost, making it the likely default for production applications that do not need Sol's ceiling.
GPT-5.6 Luna is the speed-and-cost tier: the fastest and cheapest option, suited for high-volume classification, extraction, and real-time applications where latency matters more than peak capability.
Pricing
Standard short-context API pricing per million tokens (input / output):
- Sol: $5.00 / $30.00
- Terra: $2.50 / $15.00
- Luna: $1.00 / $6.00
The Government Review Process
GPT-5.6 is the second OpenAI release to pass through the US Department of Commerce's Center for AI Standards and Innovation (CAISI) review established under the June executive order. OpenAI sent technical experts to Washington during the preview period to answer questions in real time. Commerce cleared the release ahead of schedule, enabling the July 9 launch.
This review pipeline is likely the template going forward for all major US frontier-model releases — meaning CAISI approval is becoming a permanent fixture in the model-launch calendar rather than a one-time event.
Access
In the API, the models are available as gpt-5.6-sol, gpt-5.6-terra, and gpt-5.6-luna. In ChatGPT, Sol is available to Plus, Pro, and Team subscribers immediately. Terra and Luna are API-only at launch; broader ChatGPT access is coming later in July.