OpenAI is moving its GPT-5.6 model family to general availability on Thursday, July 9, 2026, following a closed preview that started in late June with a small group of partners and U.S. government coordination. The release ships three named tiers: Sol as the flagship, Terra as a balanced everyday model, and Luna as a low-cost fast option. Pricing, benchmark results, and a Cerebras-powered Sol deployment land on the same date.<\/p>\n
OpenAI has split the version number from the capability name. The 5.6 label marks the generation; Sol, Terra, and Luna mark durable tiers that can improve between releases. For anyone tracking model behavior on a site, that distinction matters more than it sounds. A page audited against Sol today will need re-checking when Sol upgrades in place, even if the next release still carries the 5.6 label.<\/p>\n
Two new effort settings land alongside the family. A max reasoning effort setting gives Sol extended thinking time before producing output. An ultra mode goes past a single agent and coordinates subagents to push complex jobs faster. Both give developers a knob to trade latency for depth, which changes what you measure during an audit. Latency is no longer a single number per query; it depends on the effort setting.<\/p>\n
OpenAI positions Sol as state of the art on Terminal-Bench 2.1, a command-line workflow benchmark covering planning, iteration, and tool use. On GeneBench v1, a long-horizon genomics and quantitative-biology benchmark, Sol outperforms GPT-5.5 with fewer tokens. On ExploitBench, Sol stays competitive with Mythos Preview while using about one third of the output tokens. On ExploitGym, a benchmark built by UC Berkeley researchers with OpenAI and other frontier labs, all three tiers improve as reasoning effort rises.<\/p>\n
On safety, OpenAI states Sol helps users find and fix vulnerabilities more than it carries out end-to-end attacks, and that it does not cross the Cyber Critical threshold in OpenAI’s Preparedness Framework. In Chromium and Firefox evaluations, Sol identified bugs and exploitation primitives but did not autonomously produce a functional full-chain exploit under the tested conditions.<\/p>\n
OpenAI is calling GPT-5.6 its most extensive safety stack so far, configured per tier:<\/p>\n
OpenAI has warned that users may see blocks or refusals during the preview window and is collecting feedback to trim unnecessary blocks before wider release.<\/p>\n
Pricing splits across the three tiers:<\/p>\n
Terra is positioned to match GPT-5.5 while costing roughly half as much. Luna sets a new floor for frontier-tier pricing. Prompt caching is more predictable this round: explicit cache breakpoints, a 30-minute minimum cache life, cache writes billed at 1.25x the uncached input rate, and cache reads continuing at the existing 90% discount.<\/p>\n
OpenAI is bringing GPT-5.6 Sol to Cerebras hardware at up to 750 tokens per second in July. Initial access is limited to select customers. The target use cases are latency-bound workloads such as high-throughput coding agents and real-time analysis.<\/p>\n
From July 9, API and Codex access opens across all three tiers, with ChatGPT rolling out more broadly afterward. Teams already running GPT-5.5 in production should benchmark Terra first for cost parity, then run Sol through Terminal-Bench 2.1-style agentic tasks to measure gains from the new max and ultra modes. Budget-sensitive flows should set Luna as the new floor for what frontier capability costs.<\/p>\n
GPT-5.6 reaches general availability on Thursday, July 9, 2026, after a limited preview that started in late June with a small partner group in coordination with the U.S. government.<\/p>\n
Sol is the flagship tier, Terra is a balanced everyday tier, and Luna is a fast, low-cost tier. The 5.6 number marks the generation; Sol, Terra, and Luna mark tiers that can advance without a version bump.<\/p>\n
Sol is $5 input and $30 output, Terra is $2.50 input and $15 output, and Luna is $1 input and $6 output per million tokens. Cache writes are billed at 1.25x the uncached input rate with a 30-minute minimum cache life, and cache reads still receive a 90% discount.<\/p>\n