Installation

Warning

Pre-release whatif is not yet on PyPI. The instructions below assume v0.1 has shipped. Until then, install from source.

From PyPI (after v0.1)

uv pip install whatif
pip install whatif
pipx install whatif

From source

git clone https://github.com/victoralfred/whatif
cd whatif
uv sync
uv run whatif --help

Optional extras

Some adapters and scorers are gated behind extras to keep the base install small:

Extra

What it adds

When you need it

langfuse

Langfuse Python SDK

--source langfuse

inspect

Inspect AI

--score inspect_ai:... (default scorer)

anthropic

Anthropic Python SDK

reference adapter for raw-SDK runner

Install with uv pip install "whatif[langfuse,inspect,anthropic]", or install all at once with whatif[all] (once published).

Verify the install

whatif --version
whatif --help

You should see something like:

whatif 0.1.0

Supported Python versions

Python

Support

3.11

3.12

3.13

3.10

❌ (use 3.11+)

CI runs the test suite against all three supported versions on every PR.

Next

Run your first experiment.