GPT-6 Astra is OpenAI's most capable model, built for the hardest end to end work: complex reasoning, coding, computer use, research and document creation. OpenAI released it in the API on September 3, 2026, as the new top tier above Sol and Luna in the GPT-6 family.
Key facts
| Item | GPT-6 Astra |
|---|---|
| Maker | OpenAI |
| Released | September 3, 2026 |
| API model ID | gpt-6-astra |
| Context window | 1,050,000 tokens (up to 922,000 input) |
| Max output | 128,000 tokens |
| Knowledge cutoff | April 30, 2026 |
| Input / output | Text and image in, text out |
| API price per million tokens | $10 input, $1 cached input, $50 output |
Figures come from OpenAI's GPT-6 Astra model page and the API changelog, checked October 24, 2026.
Pricing details
The standard API price is $10 per million input tokens and $50 per million output tokens. Cache writes cost 1.25 times the input rate ($12.50), and cached reads cost $1. Prompts longer than 272,000 input tokens are billed at twice the input and cache rates and 1.5 times the output rate for the whole request. Batch and Flex processing cost half the standard rate, and Fast mode costs twice the applicable rate. OpenAI added an Ultrafast mode for Astra in the Responses API on September 29, 2026.
Where to use GPT-6 Astra
- API: through the Responses API and Chat Completions on the OpenAI API. Tool calling requires the Responses API, and Astra does not accept the
nonereasoning effort, custom temperature or log probabilities. - ChatGPT: Astra is rolling out on Plus, Pro, Business and Enterprise plans in ChatGPT, with Astra Pro on the higher plans. Enterprise admins switch it on for their workspace.
How it compares
Astra costs five times as much per token as GPT-6.1 Sol, which OpenAI says comes close to Astra on coding and computer use. Its closest rival at the same token price is Claude Fable 5.1. For a full walkthrough, read GPT-6 Sol vs Astra vs Luna and GPT-6 Astra vs Claude Fable 5.1.
Who should use it
Pick Astra when a cheaper model fails your own tests: long computer use tasks, hard scientific workflows, or work where a better first attempt saves expensive human time. For most other work, GPT-6.1 Sol gives similar results for a fifth of the price. See the release timeline for where Astra sits among this year's launches.