vault_update_frontmatter
Update YAML frontmatter fields in existing Obsidian notes while preserving all other content. Add, change, or remove fields with validation against the note's type.
Instructions
Update YAML frontmatter fields in an existing note. Parses existing frontmatter, updates specified fields, preserves everything else. Set a field to null to remove it. Protected fields (type, created, tags) cannot be removed. Field values are validated against the note's type (e.g. task status must be: pending, active, done, cancelled; task priority must be: low, normal, high, urgent). Paths in this tool's output are formatted as markdown links [vault-relative-path.md](obsidian://...) so users can Cmd/Ctrl-click to open in Obsidian. Preserve the link form when relaying paths to the user; pass only the bracket text (e.g. 01-Projects/Foo/note.md) to other vault tools' path arguments, never the full markdown link.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | Path relative to vault root (exact path required) | |
| fields | Yes | Fields to update. Set value to null to remove a field. Arrays (like tags) are replaced wholesale. |