0.13.8 shipped bu-2-0-mini-preview as the ChatBrowserUse default, which
means Agent(task=...) with no llm - and every bare ChatBrowserUse() -
silently moved onto a preview model on upgrade, with no code change on
the caller's side.
Two problems with that. A preview id can change behaviour or be renamed,
so it is the wrong thing to reach by omission. And per-token price is the
wrong yardstick for an agent: total cost is tokens-per-step times steps,
and steps is a function of model quality, so a cheaper-per-token model
that needs more steps to finish can cost more and take longer. We do not
yet have a per-task benchmark number for mini to say which way that goes.
bu-2-0-mini-preview stays a first-class option: still accepted, still
priced, still what the examples demonstrate. It is just opted into by
name now rather than landed on by default. Revisit once the benchmark
number exists.
Adds bu-2-0-mini-preview as an accepted model id and makes it the
constructor default, so a bare ChatBrowserUse() now routes there.
bu-2-0 is unchanged: still accepted, still documented as the premium
option, and bu-latest still resolves to it. Keeping 'latest' on the
stable line means existing callers pinned to that alias do not silently
move onto a preview model; only the bare-constructor default moves.
Pricing is registered alongside the model so cost tracking does not
silently report $0 for what is now the default. This model has no cache
discount, so cached reads bill at the input rate.
Examples, README and the model reference are updated to the new default.
The model reference also claimed bu-latest resolved to bu-1-0, which has
not been true since bu-2-0 shipped; corrected here.
Drop the bu-3 and bu-3-max model ids everywhere they were surfaced:
- ChatBrowserUse no longer lists them as valid bu-* aliases (provider-prefixed
ids like openai/gpt-5.5 are still accepted by the gateway).
- Remove their custom pricing entries and the README pricing blocks.
- Update docstrings, README quickstart, and the beta_agent example to use
openai/gpt-5.5 as the default, with bu-2-0 shown as a commented alternative.
- Drop the tests that asserted bu-3/bu-3-max acceptance and pricing.
Saurav Panda