Stac Custom Extensions

Overview

Use this skill to add custom widgets/actions that serialize cleanly and register correctly in a Stac app.

Workflow

1. Choose extension type: widget or action.
2. Scaffold model and parser files with scripts.
3. Add generated files to app codebase and run codegen.
4. Verify parser registration in main.dart.
5. Validate runtime wiring with a minimal usage example.

Required Inputs

• PascalCase extension name.
• Runtime type id (type or actionType).
• Output directory for generated files.
• Path to main.dart for registration check.

Output Contract

• Produce model + parser pair with consistent type ids.
• Include registration snippet for Stac.initialize.
• Include build_runner command when json serialization is used.

References

• Read references/custom-widget-checklist.md for widget model/parser flow.
• Read references/custom-action-checklist.md for action model/parser flow.
• Read references/parser-registration.md for initialization wiring.
• Read references/converters-guide.md for converter usage patterns.

Scripts

• scripts/scaffold_custom_widget.py --name <Name> --type <widgetType> --out-dir <path>
• scripts/scaffold_custom_action.py --name <Name> --action-type <actionType> --out-dir <path>
• scripts/check_parser_registration.py --main-dart <path> --parser-class <ClassName>

Templates

• assets/templates/custom_widget.dart.tmpl
• assets/templates/custom_widget_parser.dart.tmpl
• assets/templates/custom_action.dart.tmpl
• assets/templates/custom_action_parser.dart.tmpl