# OpenAI previews GPT-5.6 model family, claims new state of the art on Terminal-Bench

_Friday, June 26, 2026 at 2:44 PM EDT · AI · Breaking · Tier 1 — Major_

OpenAI on Friday launched a limited preview of its GPT-5.6 model family, consisting of three versions: Sol, the flagship; Terra, a balanced model for everyday work; and Luna, a fast and affordable model for high-volume tasks. The company said Sol represents a step-function improvement over GPT-5.5 and achieves a new state of the art on Terminal-Bench 2.1 for complex command-line workflows involving planning, iteration and tool use. Terra delivers performance competitive with GPT-5.5 at roughly half the cost, while Luna targets lower-cost, high-volume use. OpenAI highlighted strengths in coding, cybersecurity and long-horizon agentic tasks. It said the release includes its strongest safety stack to date, with strengthened protections against high-risk cyber activity, sensitive requests and repeated misuse after extensive red teaming. Access is currently limited to a small group of trusted partners at the request of the U.S. government. The company plans broader general availability in the coming weeks.

## Sources

- [OpenAI](https://openai.com/index/previewing-gpt-5-6-sol/)
- [OpenAI on X](https://x.com/OpenAI/status/2070555272230384038)

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Retrieved: 2026-06-26T21:51:23.593Z
Publisher: Tech & Business (techandbusiness.org)