Checked fact 8368 Oct 2026Agents and apps

OpenAI says that for GPT-5.6 and later a cached prefix remains eligible for reuse for 30 minutes after its most recent write or reuse. Quote: "A cached prefix remains eligible for reuse for 30 minutes after its most recent write or reuse, though OpenAI may retain it longer."

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A cached prefix remains eligible for reuse for 30 minutes after its most recent write or reuse, though OpenAI may retain it longer.

What the source said when we opened it, on 8 Oct 2026.

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Prompt caching
OpenAI

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Checked by the notis newsroom on 8 Oct 2026, against the source above.

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How prompt caching bills a repeated prompt start 8 Oct 2026

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“OpenAI says that for GPT-5.6 and later a cached prefix remains eligible for reuse for 30 minutes after its most recent write or reuse. Quote: "A cached prefix remains eligible for reuse for 30 minutes after its most recent write or reuse, though OpenAI may retain it longer.".” ai notis, checked 8 Oct 2026. Source: Prompt caching (OpenAI). https://ainotis.com/c/836

As a reference (APA style)

ai notis. (2026, October 8). OpenAI says that for GPT-5.6 and later a cached prefix remains eligible for reuse for 30 minutes after its most recent write or reuse. Quote: "A cached prefix remains eligible for reuse for 30 minutes after its most recent write or reuse, though OpenAI may retain it longer." [Checked claim 836]. ai notis. https://ainotis.com/c/836

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