ModelClock
Capability change
Capability change announced Sep 29, 2026
OpenAI documents a capability change: “Feature · Model: gpt-6-astra · API: v1/responses Added Ultrafast mode for GPT-6 Astra in the Responses API.”
- Hosting route
- First-party API
- Affected scope
- Not stated in the notice
- Announced
- Sep 29, 2026
- First seen by ModelClock
- Oct 3, 2026
What the provider published
developers.openai.com ↗Feature · Model: gpt-6-astra · API: v1/responses
Added Ultrafast mode for GPT-6 Astra in the Responses API. Use
gpt-6-astrawithservice_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 regional inference residency aren't supported. See Ultrafast pricing.
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