Chat model · OpenAI ·
GPT-6 Luna is a chat model by OpenAI. In Endless it costs 8.1 credits per 1M input tokens and 40.5 per 1M output tokens, on every plan.
GPT-6 Luna is OpenAI's fastest and most cost-effective GPT-6 model, made for everyday questions, simple coding and tasks you repeat often.
GPT-6 Luna launched with GPT-6 Sol on September 22, 2026, as the smallest member of the GPT-6 family and OpenAI's most efficient model for focused, high-volume tasks. It still shares the family's 1.05M-token context window and 128K-token output limit, accepts text and images, and can reason from none up to max effort when a question needs more thought.
Teams use it for the steady stream of everyday requests: pulling fields out of documents, summarizing support tickets, rewriting short copy, answering quick code questions and checking small scripts. Its knowledge runs to May 18, 2026, a few weeks later than the other GPT-6 models.
When a task outgrows Luna, such as a multi-file refactor or a long research question, move up to GPT-6.1 Sol or GPT-6 Astra in the same workspace. Credits come from the shared workspace balance, so sending routine work to Luna leaves more of it for the heavier models.
Start a chat in your workspace and choose GPT-6 Luna in the model picker.
Attach files, mention a project with @, or ask it to search the web and social media.
Generate images and video, write documents and save what matters to a project.
by OpenAI
Near-flagship agentic coding and professional work at lower cost
162 / 810 credits per 1M tokens
by OpenAI
Hard research and coding problems that need the deepest reasoning
1215 / 5062.5 credits per 1M tokens
by OpenAI
Long, complex coding sessions with deep reasoning
324 / 1620 credits per 1M tokens
Start free, create a project, and bring your brand’s references together. Or book a demo to explore Endless with your team.