Amp’s ChatGPT-linked subscription does not include every ChatGPT model. It mainly gives Amp access to OpenAI’s GPT-5.6 family through your linked ChatGPT plan, especially for Amp’s lower and mid-tier routes.[1][2]
In practical terms, the linked subscription covers these Amp routes:
Low mode:GPT-5.6 Terra for the main agent and related tasks.[1][2]
High mode:GPT-5.6 Sol for both the agent and oracle/reviewer calls, at least in the current routing described in Amp’s docs.[1][2]
Thread reader / code review: also shifted to GPT-5.6 Terra when the ChatGPT link is active.[1]
What it doesn’t include by default is Amp’s non-OpenAI routes such as Claude Fable 5 in Ultra mode; Ultra remains on Amp’s own credits rather than the linked ChatGPT subscription.[1][2][3]
So the short answer is: mostly GPT-5.6 Terra and GPT-5.6 Sol inside Amp, not the full ChatGPT model catalog, and not Ultra/Claude Fable 5.
How strongly the models agree, per check. Filled points mark checks that changed the answer.
The answer changed
The old consensus stated that High dial and Oracle use GPT-6 Astra. The new consensus reverses this, stating that Low uses GPT-5.6 Terra, Medium uses GPT-5.6 Sol, and High uses GPT-5.6 Sol, while acknowledging GPT-6 Astra as a future or changing documentation name. This is a material shift in specific model assignments.
The routing models have fundamentally shifted. The old consensus stated that ChatGPT linking covers GPT-5.6 Terra and GPT-5.6 Sol, while Ultra and others are excluded. The new consensus updates this to include GPT-6 Astra for High-mode and Oracle roles (depending on the ChatGPT tier), replacing the older GPT-5.6 assignments for those tiers.
The exact model routing breakdown substantially changed: Low main agent shifted from GLM-5.2 to GPT-5.6 Terra, High oracle shifted from Claude Fable 5 to GPT-5.6 Sol, and Code review shifted from GPT-5.5 to GPT-5.6 Terra. Additionally, the new answer specifies that Low/Med/High workflows are covered, while Ultra mode uses Claude Fable and Amp credits.
The breakdown of model assignments per routing mode changed significantly. Low mode changed from GPT-5.6 Terra to GLM-5.2 + GPT-5.6 Sol; High mode oracle changed from GPT-5.6 Sol to Claude Fable 5; Review changed from GPT-5.6 Terra to GPT-5.5; and specific routes for Puck/Search and Librarian were added while general routing details were updated.