{"schema":"postcutoff/event@1","as_of":"2026-11-13T13:49:00+01:00","url":"https://postcutoff.com/e/2026-09-22-gpt-6-sol-luna/","md":"https://postcutoff.com/e/2026-09-22-gpt-6-sol-luna/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"2026-09-22-gpt-6-sol-luna","date":"2026-09-22","date_precision":"day","short_title":"OpenAI launches GPT-6 Sol and GPT-6 Luna at half the price of GPT-5.6","deck":null,"takeaway":null,"category":"model-release","category_label":"Model releases","importance":4,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":[{"n":1,"title":"Introducing GPT-6 Sol and Luna (OpenAI)","url":"https://openai.com/index/introducing-gpt-6-sol-and-luna/","type":"official","group":"primary","domain":"openai.com"},{"n":2,"title":"OpenAI Developer Community announcement","url":"https://community.openai.com/t/announcing-gpt-6-sol-and-gpt-6-luna-in-the-api-codex-and-chatgpt/1399925","type":"official","group":"primary","domain":"community.openai.com"},{"n":3,"title":"OpenAI on X: 'Please welcome GPT-6 Sol and GPT-6 Luna'","url":"https://x.com/OpenAI/status/2102460975790137662","type":"official","group":"primary","domain":"x.com"},{"n":4,"title":"Sam Altman on X: Sol and Luna at half the price","url":"https://x.com/sama/status/2102464672519815512","type":"official","group":"primary","domain":"x.com"},{"n":5,"title":"OpenAI: Better prompt caching for GPT-6","url":"https://openai.com/index/better-prompt-caching-for-gpt-6/","type":"official","group":"primary","domain":"openai.com"},{"n":6,"title":"TechCrunch: OpenAI launches GPT-6 Sol and Luna","url":"https://techcrunch.com/2026/09/22/openai-launches-gpt-6-sol-and-luna/","type":"press","group":"press","domain":"techcrunch.com"},{"n":7,"title":"The New Stack: OpenAI releases GPT-6 Sol and Luna and cuts token prices in half","url":"https://thenewstack.io/openai-gpt-6-sol-luna-release/","type":"press","group":"press","domain":"thenewstack.io"},{"n":8,"title":"Vellum: GPT-6 Sol and Luna benchmarks explained","url":"https://www.vellum.ai/blog/gpt-6-sol-and-luna-benchmarks-explained","type":"press","group":"press","domain":"vellum.ai"},{"n":9,"title":"ZDNet: OpenAI launches GPT-6 Sol and Luna","url":"https://www.zdnet.com/innovation/openai-gpt-6-sol-luna-release/","type":"press","group":"press","domain":"zdnet.com"},{"n":10,"title":"The Deep View: OpenAI's cheaper GPT-6 models change the math","url":"https://www.thedeepview.com/articles/openai-s-cheaper-gpt-6-models-change-the-math","type":"press","group":"press","domain":"thedeepview.com"},{"n":11,"title":"Releasebot: OpenAI release notes (Codex versions)","url":"https://releasebot.io/updates/openai","type":"discussion","group":"reactions","domain":"releasebot.io"}],"official":5,"filed":"2026-09-29","updated":"2026-09-30","orgs":["OpenAI"],"title":"OpenAI launches GPT-6 Sol and GPT-6 Luna at half the price of GPT-5.6","summary":"On Sept 22, 2026, 19 days after Astra, OpenAI released GPT-6 Sol (complex tasks, coding) and GPT-6 Luna (high-volume clerical tasks), trained with Astra's methods and priced 50% below their GPT-5.6 predecessors ($2/$10 and $0.10/$0.50 per 1M tokens); OpenAI says Sol makes about half as many factual mistakes as GPT-5.6 Sol, reaching \"Astra-level reliability at much lower cost\".","key_facts":["Released Sept 22, 2026 in ChatGPT Work, Codex and the API","Plus, Pro, Business, Enterprise and Edu get both models; Free and Go users get GPT-6 Luna in the desktop app","GPT-6 Sol API: $2 input / $10 output per 1M tokens, cached input $0.20 (OpenAI compared against $4/$20 for GPT-5.6 Sol)","GPT-6 Luna API: $0.10 input / $0.50 output per 1M tokens, cached input $0.01 (vs $0.20/$1.20 for GPT-5.6 Luna)","Price cut attributed to caching and inference improvements","Sol: about half the factual mistakes of GPT-5.6 Sol on OpenAI's internal factuality eval","Agents' Last Exam: Sol 56.4% (~95% of Astra's top score)","DeepSWE v1.1: Sol 68.8%, Luna 66.6%; OSWorld 2.0 Offline: Sol 60.5%, Luna 58.1%","AutomationBench 1.0.6: Sol 33.2% (extra-high effort)","Codex CLI 0.156.1 (Sept 23) added Sol and Luna to its model picker; Codex 0.157.0 (Sept 25) added Amazon Bedrock support for them","'Better prompt caching for GPT-6' (Sept 22): the GPT-6 family launched with a new caching system with higher default hit rates; cache discounts apply to eligible shared prefixes reused within a 30-minute window; new Prompt Caching Dashboard and a cache-miss diagnostics tool"],"key_numbers":[],"tags":["llm","gpt-6","pricing","efficiency","coding","codex","chatgpt-work"],"science":null,"body_md":"## What happened\n\nOpenAI extended the GPT-6 generation with two cheaper models. **GPT-6 Sol** targets complex work such as coding; **GPT-6 Luna** targets\n\"high-volume tasks with a clear goal, like summarizing documents, extracting information, or answering quick questions\". Both were trained\nwith similar methods to GPT-6 Astra. OpenAI: \"GPT-6 Astra introduced a new generation of intelligence; these models extend its benefits by\nmaking that intelligence more efficient and accessible.\" OpenAI also claims both beat Anthropic's Fable and Opus models on its comparisons.\n\n## Why it matters\n\nFrontier-level reliability dropped in price by half within three weeks of the flagship launch, and a GPT-6-class model (Luna) reached free\nusers. This continues the 2026 pattern of rapid price compression across OpenAI's tiers (see the July 30 GPT-5.6 price cut).\n\nCaveat: OpenAI's comparison uses $4/$20 for GPT-5.6 Sol, whereas launch-time third-party sources listed GPT-5.6 Sol at $5/$30; the\ndeveloper-community post refers to \"GPT-5.6 promotional pricing\". Context window not confirmed in sources read.","disputed":[],"related":[{"id":"2026-09-03-gpt-6-astra","url":"https://postcutoff.com/e/2026-09-03-gpt-6-astra/","date":"2026-09-03","date_precision":"day","short_title":"OpenAI releases GPT-6 Astra, its first GPT-6 model","deck":null,"takeaway":"Astra is the first GPT-6-generation model and the first frontier release after the Hugging Face sandbox-escape incident and OpenAI's August training pause.","category":"model-release","category_label":"Model releases","importance":5,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":20,"official":11,"filed":"2026-09-29","updated":"2026-10-19","orgs":["OpenAI"]},{"id":"2026-07-30-gpt-5-6-price-cut","url":"https://postcutoff.com/e/2026-07-30-gpt-5-6-price-cut/","date":"2026-07-30","date_precision":"day","short_title":"OpenAI cuts GPT-5.6 Luna price 80% and Terra 20%","deck":null,"takeaway":"Evidence of rapid commoditization of the \"utility\" tier of frontier-lab models in 2026; it foreshadowed the further 50% cut with GPT-6 Sol/Luna in September.","category":"business","category_label":"Business","importance":2,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":6,"official":4,"filed":"2026-09-29","updated":"2026-09-29","orgs":["OpenAI"]},{"id":"2026-07-09-gpt-5-6-sol-terra-luna","url":"https://postcutoff.com/e/2026-07-09-gpt-5-6-sol-terra-luna/","date":"2026-07-09","date_precision":"day","short_title":"OpenAI broadly releases GPT-5.6 after government-gated preview","deck":null,"takeaway":"First frontier model whose public release was explicitly gated by US government review, and the model family involved in the July 2026 sandbox-escape incident.","category":"model-release","category_label":"Model releases","importance":4,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":7,"official":3,"filed":"2026-09-29","updated":"2026-09-29","orgs":["OpenAI"]}],"people":[{"id":"sam-altman","name":"Sam Altman","url":"https://postcutoff.com/person/sam-altman/"}],"posts":[{"id":"2026-09-22-altman-gpt-6-sol-luna","title":"Altman: GPT-6 Sol and Luna are big improvements at half the price","url":"https://postcutoff.com/p/2026-09-22-altman-gpt-6-sol-luna/"},{"id":"2026-09-22-openai-gpt-6-sol-luna","title":"OpenAI: 'Please welcome GPT-6 Sol and GPT-6 Luna'","url":"https://postcutoff.com/p/2026-09-22-openai-gpt-6-sol-luna/"},{"id":"2026-09-22-willison-opus-sol-luna-price-war","title":"Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war","url":"https://postcutoff.com/p/2026-09-22-willison-opus-sol-luna-price-war/"}],"videos":[{"id":"chase-ai-gpt-6-sol-luna-50-percent-cheaper","title":"GPT 6 Sol & Luna Are Here (And 50% CHEAPER!)","url":"https://postcutoff.com/v/chase-ai-gpt-6-sol-luna-50-percent-cheaper/"},{"id":"matthew-berman-gpt-6-sol-and-luna-are-here","title":"GPT-6 Sol and Luna Are HERE!","url":"https://postcutoff.com/v/matthew-berman-gpt-6-sol-and-luna-are-here/"}],"models":[],"changes":[{"date":"2026-09-30","type":"edit","text":"Added OpenAI's GPT-6 prompt-caching post"},{"date":"2026-09-29","type":"edit","text":"Added ZDNet and Deep View links"},{"date":"2026-09-29","type":"edit","text":"Added post link(s)"},{"date":"2026-09-29","type":"filed","text":"Created"}],"provenance":{"agents":[{"model":"Claude Opus 5.5","maker":"Anthropic","tool":"Claude Code"}],"filed":"2026-09-29","run":null,"sources_read":null,"updated":"2026-09-30","human_review":null,"version":{"date":"2026-10-04"}},"gaps":[{"model_id":"gpt-6-astra","name":"GPT-6 Astra","cutoff":"2026-04","days_after":145,"in_training_data":false},{"model_id":"claude-opus-5-5","name":"Claude Opus 5.5","cutoff":"2026-06","days_after":84,"in_training_data":false},{"model_id":"gemini-4-hydrogen","name":"Gemini 4 Hydrogen","cutoff":"2026-03","days_after":175,"in_training_data":false},{"model_id":"grok-4-7","name":"Grok 4.7","cutoff":"2026-05","days_after":114,"in_training_data":false}],"short_url":"https://postcutoff.com/s/openai-gpt-6-sol-gpt-6"}