Amp's agent modes are now a dial: low
, medium
, high
, ultra
. They replace smart
, deep
, rush
, and large
.
The old modes were models in disguise: each name hid a model, a prompt, a reasoning effort — and to pick one, you had to know what that model was like this month. That world is gone. The models converged, open-weight models got seriously good, and the only question left is capability against cost.
The dial asks one question: how hard is this task?
Missing in either direction costs you. Undershoot and the model churns: wrong fix, re-prompt, wrong fix again. You pay three times for a result you could have had once. Overshoot and you're using Fable to fix a typo. Set it right and you pay for exactly the intelligence the task needs.
ultra
high
medium
gets you — but plan on one round of feedback before merging, and about twice the wait.medium
low
low
builds it.Turn the dial with Ctrl+S
in the CLI, or with the mode picker in the web app.
We want you to know exactly what you're getting, so here's what backs each mode today. This wiring will change as models improve. The dial won't.
ultra
: Claude Fable 5, with a system prompt written for it. GPT-5.5 as the oracle.high
: GPT-5.5 at xhigh
reasoning effort. Claude Fable 5 as the oracle.medium
: GPT-5.5 at medium reasoning effort. GPT-5.5 at high effort as the oracle.low
: GLM-5.2, Z.ai's open-weight model, the strongest open model on agentic coding. GPT-5.5 as the oracle. (Workspace admins can choose to use GPT-5.5 low instead of GLM-5.2 here.)Reasoning effort is part of the tier now. No more cycling Opt+D
through effort levels on top of picking a mode.
Every mode has an oracle for second opinions. On the top tiers, it's the other frontier model: in high
, GPT-5.5 writes and Fable reviews. In ultra
, Fable writes and GPT-5.5 reviews.
smart
, deep
→ medium
(same model and effort as deep
). Turn up for hard problems.rush
→ low
.deep**3
-> frontier
or high
The dial removes knobs from the default experience, not from Amp. Plugins can register their own agent modes with your model, your prompt, and your tools, and they show up right next to the built-in ones.
We used that same plugin API to package up the deprecated modes — exact system prompts, exact tool lists, same models and reasoning efforts. If you want smart
, deep
, rush
, or large
back, install them:
amp plugins add --auto-update @amp/smart-classic
amp plugins add --auto-update @amp/deep-classic
amp plugins add --auto-update @amp/rush-classic
amp plugins add --auto-update @amp/large-classic
Then run plugins: reload
(or restart the CLI) and they appear in the mode picker as Smart (classic), Deep (classic), Rush (classic), and Large (classic) — the original names stay reserved for the built-ins. --auto-update
keeps them current when we update the plugins; drop it if you'd rather pin. The full list of installable modes is on ampcode.com/models.
Start at medium
. Turn it down when the task is clear. Turn it up when a miss costs more than the wait.
We'll follow up with posts on each mode and numbers on what each one can handle.