# Propsec > This is a fork of [github.com/ccmdi/propsec](github.com/ccmdi/propsec). > > New changes were written by a human-led AI agent. 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: <p align="center"> <img src="images/example.png"> </p> Once saved, violating notes such as this one... <p align="center"> <img src="images/example2.png"> </p> ...will be caught by the validation: <p align="center"> <img src="images/example3.png"> </p> ## 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 notes 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` | Notes directly in Journal folder | | `Journal/*` | Notes in Journal and all subfolders | | `#book` | Notes with #book tag | | `Projects/* or #active` | Notes matching either condition | You can also narrow which notes a schema applies to with properties: - `File name matches`: Filter by file name (regex) - `Modified after` / `Modified before`: Filter by modification date - `Created after` / `Created before`: Filter by creation date - `Has property` / `Missing property`: Filter by property existence - `Property 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 nes…