nab

A PubGrub-based dependency resolver for Python packages.

nab is resolve-only: it produces a pinned set of versions (or a PEP 751 lockfile) but never installs. Hand the lockfile to whatever installer you trust.

Where to start

• New to nab: work through getting started.

• A task in mind: the how-to guides cover installing nab, local checkouts, VCS sources, multiple indexes, and workspaces.

• Looking something up: the reference covers the [tool.nab] keys, the CLI, the lockfile formats, and the build policy.

• Want to know how something works: the explanations cover universal resolution and conflicting extras and groups.

Tutorial

• Getting started

How-to guides

• Install nab
• Use a local checkout as a source
• Add a VCS dependency
• Lock with multiple indexes
• Lock a workspace

Reference

• CLI
• Configuration
• Lockfiles
• Build policy

Explanation

• Universal resolution
• Conflicting extras and groups

Project

• Contributing

Status

• Single-environment resolution against PyPI

• Multiple indexes, per-package routing, and local-checkout sources

• VCS dependency admission with policy controls (Layer 2: clone + static metadata)

• Direct-URL .tar.gz archive sources, hash-verified and pinned as PEP 751 packages.archive

• PEP 751 lockfile emission via the upstream packaging library

• Universal resolution across a user-declared (python, platform, implementation) matrix. Opt-in via [tool.nab].mode = "universal"; the API and output format are still subject to change.

• Mutually-exclusive extras and dependency groups via [tool.nab].conflicts: co-selected members fork the resolve, in specific and universal mode. See conflicts.