Preferred Stack — uv over pip, and other defaults

Short, sharp guidance to keep agents from defaulting to the wrong tool when the user has a clear preference. Update as preferences harden.

Python: use uv, not pip

Rule. When installing Python packages, default to uv over pip. Use uv pip install <pkg> for one-off installs, uv pip install -r requirements.txt for project deps, and uv add <pkg> when working in a project that already uses a uv-managed pyproject.toml.

Why: the user prefers uv for its speed, deterministic resolution, and modern dependency-management ergonomics. Repeated pip invocations from agents create friction; the user has explicitly flagged this as a guidance point worth memorializing.

How to apply:

• In documentation and READMEs: lead with uv pip install ... examples; note the plain pip form as a fallback for users who don’t have uv installed.
• In scripts that bootstrap dependencies: assume uv available; fall back to pip only with a clear message.
• Don’t retroactively reinstall packages that were already installed with plain pip in a session — the user has confirmed that’s wasted effort. Just switch going forward.
• Don’t install pip packages into the user’s global / pyenv environment without surfacing the install. Prefer adding to a project’s requirements.txt or pyproject.toml and letting the user run the install command, OR run uv pip install and explicitly note what landed where.

Other defaults (extend as they emerge)

This file is the home for stack-preference reminders that span multiple projects in ai-labs/. As new preferences come up — preferred testing framework, preferred logging library, preferred HTTP client, etc. — append a new section here rather than scattering them across project READMEs.

When a preference is project-specific (e.g., “this kit uses chromadb for vectors”), document it in the project’s own README.md or context-v/blueprints/. This file is for cross-project defaults only.

Related

• [[context-vigilance]] skill — for what a reminder is and how it should be shaped
• [[Collate-Context-Files-into-Context-Vigilance-as-Repo-&-Project]] — exploration where the kit’s requirements.txt lives
• [[ChromaDB-as-Context-Improvement-Across-Everything-Everyone]] — adjacent exploration; Python deps install pattern from this preference applies