UV Integration¶

Pascal is designed to sit alongside UV, not replace it. The division of responsibility is clean:

How they fit together¶

pascal init        →  writes pascal.toml + UV workspace root pyproject.toml
pascal create      →  adds a new UV workspace member
pascal add         →  edits pyproject.toml, adds [tool.uv.sources] entry
pascal sync        →  regenerates UV workspace root pyproject.toml
pascal test        →  calls: uv run pytest
pascal build       →  calls: uv build
pascal run         →  calls: uv run <entry-point>

You can always drop into raw uv commands — pascal only ever writes standard UV workspace files.

UV workspace model¶

A UV workspace is a monorepo layout where multiple pyproject.toml files share a single uv.lock. Pascal generates and maintains the workspace root:

# <workspace-root>/pyproject.toml
[tool.uv.workspace]
members = ["packages/*", "apps/*"]

Each member is a standard Python package with its own pyproject.toml. UV resolves all members together into a single lockfile.

Path dependencies via [tool.uv.sources]¶

When you run pascal add cart --to storefront, pascal writes:

# apps/storefront/pyproject.toml
[project]
dependencies = ["cart"]

[tool.uv.sources]
cart = { workspace = true }

The workspace = true source tells UV to resolve cart from the local workspace rather than downloading it from PyPI.

Typical workflow¶

# Day 1: set up
pascal init my-ws && cd my-ws
pascal create package cart
pascal create app storefront
pascal add cart --to storefront
uv sync                          # installs everything, creates uv.lock

# Day N: add a dependency
pascal add auth --to storefront
uv sync                          # updates lockfile

# Day N: run things
pascal test
pascal run storefront

# CI: targeted testing
pascal test --changed --since origin/main

Lock file¶

uv.lock is managed entirely by UV. Pascal never touches it. Commit it to git — it ensures reproducible installs across machines and CI.

Virtual environments¶

UV creates a single .venv at the workspace root shared by all members. You don't need to activate it manually — uv run handles it automatically.

# These all work without activating a venv:
uv run python -c "import cart"
uv run pytest packages/cart/tests/
pascal test cart