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GPT-6 Astra
OpenAI · GPT-6
OpenAI released GPT-6 Astra on September 3, 2026.
GPT-6 Astra is the OpenAI model released on September 3, 2026 as its most capable model, built for the hardest end-to-end work. OpenAI positions it for reasoning, coding, computer use, research and document creation, carrying complex tasks from an initial request to a finished result using the context and tools provided. It is available in the Responses and Chat Completions APIs. New Responses API controls launched alongside it: async tool calling, mid-turn steering over WebSockets, and changing reasoning effort mid-conversation while preserving the cached prompt. Ultrafast mode for Astra followed on September 29.
GPT-6 Astra at a glance
- Released
- API model id
gpt-6-astra- Available on
- OpenAI API
- Previous model
- GPT-5.6 (July 9, 2026)
- Announcement
- developers.openai.com
What changed from GPT-5.6
Key changes when migrating: GPT-6 Astra does not support the none reasoning effort level, custom temperature or top_p, or logprobs, and tool calling requires the Responses API.
Misalignment monitoring asynchronously checks agent work in supported Responses API requests and can raise safety alerts or stop a conversation for review.
New to model names and version numbers? Read how AI labs version their models.
GPT-6 Astra release timeline
The launch and every later OpenAI release that mentions GPT-6 Astra, oldest first.
- Released GPT-6 Astra
Released GPT-6 Astra , our most capable model, built for the hardest end-to-end work. Use GPT-6 Astra for reasoning, coding, computer use, research, and document creation. It combines these capabilities to carry complex tasks from an initial request to a finished result, using t…
Source: OpenAI API Changelog - Async tool calling and mid-turn steering for GPT-6 Astra
Added new controls for long-running work with GPT-6 Astra in the Responses API: Async tool calling : Let the model continue working while your application runs function or custom tools, then return results as they become available. Mid-turn steering : Send additional instruction…
Source: OpenAI API Changelog - Released GPT-6.1 Sol (gpt-6.1-sol)
Released GPT-6.1 Sol (gpt-6.1-sol) for complex coding and professional work at a lower cost than GPT-6 Astra. Standard pricing per 1M tokens for prompts with up to 272K input tokens is $2 input, $0.10 cached input, $2.50 cache write, and $10 output. GPT-6.1 Sol also supports Mul…
Source: OpenAI API Changelog - Ultrafast mode for GPT-6 Astra
Added Ultrafast mode for GPT-6 Astra in the Responses API. Use gpt-6-astra with service_tier: "ultrafast" to reduce the time between generated output tokens. It is available to API customers, subject to rate limits, with global processing and US data residency. EU and other regi…
Source: OpenAI API Changelog
GPT-6 Astra FAQ
When was GPT-6 Astra released?
OpenAI released GPT-6 Astra on September 3, 2026. The launch entry below links to the official announcement.
Where is GPT-6 Astra available?
GPT-6 Astra is available on OpenAI API. Later availability changes are listed under follow-up releases on this page.
What is the GPT-6 Astra API model id?
Use gpt-6-astra in OpenAI's API.
What came before GPT-6 Astra?
GPT-6 Astra follows GPT-5.6, released on July 9, 2026.
Other OpenAI models
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