Propsec

Schema enforcement for Obsidian frontmatter.

Define schemas based on templates or invariants in your vault, add custom reusable types, and more.

Why

Obsidian properties are freeform. Over time, things can break: you change the structure, use an old field, etc. This plugin validates notes against schemas you define. Your notes are untouched, but your vault's consistency becomes easier to manage.

Setup

1. Open plugin settings
2. Create a schema: click + Add Schema
3. Set a query to target files
4. Add fields: name, type, required/optional
5. Violations appear in the status bar/sidebar

Schema definition

The query field allows schema matching based on file paths and/or tags:

Query	Matches
Journal	Files directly in Journal folder
Journal/*	Files in Journal and all subfolders
#book	Files with #book tag
Projects/* or #active	Files matching either condition

You can also narrow which files a schema applies to with properties:

• fileNamePattern: Filter by file name (regex)
• modifiedAfter / modifiedBefore: Filter by modification date
• createdAfter / createdBefore: Filter by creation date
• hasProperty / notHasProperty: Filter by property existence
• conditions: Filter by property values (property-operator-value list)

Field Types

Primitives: string, number, boolean, date, array, object, null, unknown

Custom Types: Define reusable types in settings. A custom type is a named group of fields. Use them when multiple schemas share the same structure or you need nested validation.

Union Types: Add multiple field entries with the same name but different types. For example, two entries for status with types string and null creates string | null.

Fields can be flagged to be required (key is required) xor warn (soft requirement). There is also a unique constraint that prevents duplicate values on that field.

Finally, there are cross-field constraints (compare this field's value to another field) and conditional validation (only validate this field when another field matches a condition).

Constraints

Each field type supports optional constraints:

Type	Constraints
string	pattern (regex), minLength, maxLength
number	min, max
array	minItems, maxItems, contains (required values)
date	min, max

Installation

Copy to .obsidian/plugins/ or install via BRAT.