Features

Bundling

• Targets. single gives one .py, pyz a zipapp, tree a pruned directory and lambda a reproducible AWS Lambda zip. See Targets.
• Library entries. --export handler keeps a function called from outside (a Lambda handler or a plugin hook). The entry is then imported as a module, not run as __main__.
• Dependencies. Third-party packages are shipped whole in tree-shaped targets, or bundled and shaken with include. --uv installs the versions pinned in uv.lock for a target platform.

Shaking

• Unused functions, classes, constants and imports are removed across modules, and so are modules that nothing reachable imports.
• Kept from m import a, b statements drop the names nobody uses.
• importlib.import_module("plugins." + name) bundles every module under plugins, like esbuild's glob imports.

Safety and debugging

• Conservative effect analysis, explained in Side effects.
• Exact tracebacks: original file names, line numbers, carets and source text.
• Removed names reached at runtime fail with a note that names the keep setting to add.
• minify keeps line numbers exact. shakeout trace restores the original lines of a traceback.
• A build manifest records the build ID, modules, removals and the Lambda handler.