We changed the Dial. Link a ChatGPT subscription and low, medium, and high only use OpenAI models: as the main agent, as the oracle, as the thread reader, as code review. Every model behind those modes is an OpenAI model, billed to your subscription.
Before this change, you'd still pay for tokens with a subscription linked, because parts of the work ran on other models: low and the thread reader on GLM-5.2, the high oracle on Claude Fable, code review on Haiku — all billed to Amp credits. That confused people, and we get why.
With a subscription connected:
lowruns GPT-5.6 Terra instead of GLM-5.2.mediumruns GPT-5.6 Sol, as before.highruns GPT-5.6 Sol as both agent and oracle. The oracle used to be Fable.- The thread reader and code review move to GPT-5.6 Terra.
Doesn't this make the modes worse? Barely, and less every month. The frontier models have converged: any of them gets you to a good result with a good harness. We swapped the default model for most users overnight and nobody complained. So the modes stay at the frontier, and the tokens come out of a subscription you already pay for.
high also drops its credit minimum when your subscription is active. There's no Fable call left to pay for.
ultra doesn't change. It runs Claude Fable on credits, because ultra is for the tasks where you want the strongest model, whatever it costs.
If you don't have a subscription, nothing changes. The modes run as before, on Amp credits.
Link your subscription and turn the dial.