Installed capability plugins¶

A distribution registers a Click Command (including Group) directly:

[project.entry-points."livingproof.capability.commands"]
report = "livingproof_capability_report.cli:report"

This maps livingproof capability report to the original command object, preserving its options, nested commands, errors and exit codes. No umbrella import or dependency is needed in the plugin. Python's installed distribution metadata is the discovery mechanism; no separate shared-contracts package is required.

Names must match [a-z][a-z0-9-]*; invalid names are ignored. Names are listed in sorted order. Duplicate providers for a name fail explicitly when selected, even if both point to the same object; installation order never chooses a winner. Group help reads metadata without importing plugin code. A plugin imports only when selected (including its help/completion), and must expose a Click Command. Load failures become concise Click errors; they do not break root/group help. The reserved missing-plugin guidance for report disappears when it is installed. Unknown names retain Click's normal usage error.

Installed plugin code runs with the user's privileges. Install trusted packages explicitly. Discovery performs no network access, installation or arbitrary file loading. Dependencies and upgrades remain the user's package-manager decision. This first contract provides capability commands only; broader command namespaces and provider orchestration should follow demonstrated needs.