Required field • Katalyst Documentation

Check type ID#

kind: object_required_field

Purpose#

Require that a frontmatter field exists.

Configuration keys#

Field	Required	Default	Meaning
`field`	yes	-	Frontmatter key that must be present.

Example#

collections:
  notes:
    path: notes
    checks:
      - kind: object_required_field
        field: year

Worked example#

The books collection binds the book schema (title plus an integer year). dune.md satisfies the schema and reports OK; foundation.md omits year, so check reports the missing required property and exits 1.

Input#

notes/books/dune.md

---
title: Dune
year: 1965
---
# Dune

notes/books/foundation.md

---
title: Foundation
---
# Foundation

.katalyst/storage/my_directory.yaml

type: filesystem
root: .
collections:
  books:
    path: notes/books
    schema: book

.katalyst/schemas/book.yaml

$schema: https://json-schema.org/draft/2020-12/schema
title: book
type: object
required: [title, year]
properties:
  title: { type: string, minLength: 1 }
  year:  { type: integer, minimum: 0 }

Command#

$ katalyst check books
<project>/notes/books/dune.md: OK
<project>/notes/books/foundation.md: /: missing property 'year'
exit status 1