Obsidian Note Auto-Tagging
Automatically analyze your Obsidian notes and add relevant tags based on content.
You have 500 notes in your Obsidian vault and half of them have no tags. Finding anything means searching by keyword and hoping you used the right word. Your knowledge graph is sparse because without consistent tags, connections between ideas stay invisible.
Who it's for: Obsidian users with large untagged vaults needing retroactive organization, knowledge workers building second-brain systems that rely on tag taxonomies, researchers organizing literature notes by theme and methodology, students tagging course notes for exam review, writers categorizing idea captures for future reference
Example
"Auto-tag my 300 untagged Obsidian notes" → Consistent tag taxonomy applied across all notes based on content analysis, with tag suggestions matching your existing tag conventions, a summary of new tags created, and before/after graph density comparison
New here? 3-minute setup guide → | Already set up? Copy the template below.
# Obsidian Auto-Tagger
## Goal
Analyze markdown notes and add relevant YAML frontmatter tags.
## Tag Categories
- Topics: #project, #idea, #meeting, #daily, #weekly, #reference
- Status: #todo, #in-progress, #done, #archived
- Priority: #urgent, #important, #someday
- Areas: #work, #personal, #health, #finance, #learning
## Rules
1. Read each .md file in the vault
2. Analyze the content for themes and topics
3. Add a YAML frontmatter block if missing
4. Add 2-5 relevant tags based on content
5. Don't remove existing tags
6. Don't modify the note content, only frontmatter
## Frontmatter Format
---
tags:
- tag1
- tag2
---
## Skip
- Files in .obsidian/ folder
- Files that already have 3+ tags
- Template files in Templates/
What This Does
This playbook analyzes your Obsidian markdown notes and automatically adds relevant tags based on their content. It helps you organize your vault without manually tagging every note.
Prerequisites
- Claude Code installed and configured
- An Obsidian vault with markdown (.md) files
- Notes that need tagging
Step-by-Step Setup
Step 1: Navigate to your Obsidian vault
cd ~/Documents/ObsidianVault # or your vault location
Step 2: Create the CLAUDE.md file
Create a new file called CLAUDE.md and paste the template above.
Step 3: Test on a single note first
Run Claude Code and ask it to tag just one note:
claude "Tag the note at notes/my-note.md according to the CLAUDE.md rules"
Step 4: Tag all notes (batch)
Once you're happy with the results:
claude "Tag all untagged notes in this vault according to the CLAUDE.md rules"
Example
Before (notes/meeting-notes.md):
# Team Standup - January 9
Discussed the new feature rollout. John will handle backend,
Sarah takes frontend. Need to finish by Friday.
Action items:
- Review PR #123
- Update documentation
- Schedule demo with stakeholders
After:
---
tags:
- meeting
- work
- project
- todo
---
# Team Standup - January 9
Discussed the new feature rollout. John will handle backend,
Sarah takes frontend. Need to finish by Friday.
Action items:
- Review PR #123
- Update documentation
- Schedule demo with stakeholders
Tips & Variations
- Custom tag vocabulary: Modify the tag categories to match your existing tagging system
- Hierarchical tags: Use nested tags like
#work/meetingsor#project/alpha - Add more metadata: Extend the frontmatter to include
created,modified, or custom fields
Troubleshooting
Problem: Tags don't appear in Obsidian
Solution: Make sure the YAML frontmatter is at the very top of the file with no blank lines above it.
Problem: Getting irrelevant tags
Solution: Refine your tag categories in the CLAUDE.md to be more specific, or add examples of what each tag means.