Types and Inheritance

Bowerbird uses strict type inheritance to reduce duplication and ensure consistency.

Type Hierarchy

Types form a single-inheritance tree. Every type extends exactly one parent, and all types ultimately inherit from meta:

meta (global fields)
├── reflection
│   ├── daily-note
│   └── idea
├── objective
│   ├── task
│   └── milestone
└── entity
    ├── person
    └── place

Defining Types

Types are defined with the extends property linking to their parent:

{
  "types": {
    "meta": {
      "fields": {
        "status": { "prompt": "select", "options": ["raw", "active", "done"] },
        "created": { "value": "$NOW" }
      }
    },
    "objective": {
      "fields": {
        "deadline": { "prompt": "date" }
      }
    },
    "task": {
      "extends": "objective",
      "fields": {
        "priority": { "prompt": "select", "options": ["low", "medium", "high"] }
      }
    }
  }
}

A task note gets:

• status and created from meta
• deadline from objective
• priority from itself

Inheritance Rules

1. Single inheritance — Each type has exactly one parent
2. Unique names — Type names must be unique across the entire schema
3. No cycles — A type cannot extend its own descendant
4. Override defaults only — Child types can override default values, but not field structure

Field Types

Fields define what data each note type collects:

• Static — Fixed value: { "value": "$NOW" }
• Text — Free input: { "prompt": "text" }
• Select — Choose from options: { "prompt": "select", "options": [...] }
• Relation — Link to other notes: { "prompt": "relation", "source": "milestone" }
• Number, Boolean, Date, List — Other prompt types

Next Steps

• Schema Reference — Complete property reference
• Migrations — Evolving your type system