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Language modelLimited access

GPT-6 Astra

OpenAI

Released
September 3, 2026
Data date
September 24, 2026
Predecessor
GPT-5.6 Sol
Speed
63.4 tokens/s
Output throughput
Price
$10 · $50
Input · Output / 1M tokens
Input
Text, Image
Output
Text

With GPT-6 Astra, OpenAI introduced an experimental approach to long-term context in Codex. The model can keep notes across context windows and search earlier messages or tool results. During lengthy debugging work, fewer details need to be repeatedly compressed into a single summary.

OpenAI classifies Astra’s cybersecurity capability as Critical under its Preparedness Framework. The release therefore includes additional safeguards and restrictions on certain security tasks. GPT-6.1 Sol approaches Astra on several coding and professional-work evaluations, while OpenAI still reports an advantage for Astra on its hardest scientific tasks.

Specifications and access

SpecificationValue and source
Weights
ProprietarySource
Access
APISource
Context window
1,050,000 tokensSource
Knowledge cutoff
April 30, 2026Source
Notes
New OpenAI flagship with a 1.05 million token context window, 128,000 maximum output tokens, and an April 30, 2026 knowledge cutoff. Access has been rolling out in phases since September 3, 2026. Since September 22, 2026, GPT-6 Sol and GPT-6 Luna complete the family as lower-cost tiers.Source
API model ID
gpt-6-astraSource
Release
2026-09-03Source
Maximum output
128,000 tokensSource
Input
Text, ImageSource
Output
TextSource
Reasoning mode
low, medium, high, xhigh, maxSource
API interfaces
Responses API, Chat Completions APISource
Tool calling
YesSource
Structured output
YesSource