Propsec

Schema enforcement for Obsidian properties.

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

Usage

First, define a schema:

Once saved, violating notes such as this one...

...will be caught by the validation:

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. Write a rule for which notes it applies to, e.g. file.inFolder("Books")
4. Add fields: name, type, required/optional, and optional rules
5. Violations appear in the status bar/sidebar

Rules

Everything that picks or checks something is a rule, written in a small expression language. Press Ctrl+Space in a rule box for helpers like "at most N characters" or "in folder". This will insert the rule for you.

Where	Example	Meaning
Schema: applies to	file.inFolder("Books") || file.hasTag("book")	Notes in Books, or tagged #book
Field: value must	size(it) >= 1 && size(it) <= 5	Between 1 and 5 items
Field: value must	it.exists(t, t.matches("^genre/"))	Has a tag starting with genre/
Field: value must	it >= started	On or after the started property
Field: applies when	status == "finished"	Only check this field for finished notes
Settings: excluded notes	file.hasTag("archived")	No schema checks archived notes

A rule reads properties by name (rating, or note["date created"] when the name has spaces), the field's own value as it, and the file through file: file.path, file.name, file.folder, file.tags, file.mtime, file.ctime, file.inFolder(...), file.hasTag(...).

The syntax follows CEL, adjusted for frontmatter.

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.

Field flags

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