# Extending StaticPHP

<!-- TODO: Introduce the three extension strategies:
  1. Contributing to core — edit src/Package/ and config/pkg/ directly.
  2. External Registry — point SPC_REGISTRIES at a custom spc.registry.yml.
  3. Vendor Mode — package classes + config as a Composer library (composer require).
  Explain when to use each approach. Show a minimal end-to-end example:
  one Library class, one config YAML, one spc.registry.yml, run spc. -->