---

name: ontology-engine description: Convert markdown vault to RDF/TTL knowledge graph. Extract persons, projects, meetings, and relationships into semantic triples.

Ontology Engine

Convert markdown vault to RDF/TTL ontology for semantic querying.

Usage

Build Knowledge Graph

Copysource .venv/bin/activate && \
python .claude/skills/ontology-engine/scripts/vault_to_ttl.py ./vault --output ./knowledge.ttl

With Custom Folders

Copysource .venv/bin/activate && \
python .claude/skills/ontology-engine/scripts/vault_to_ttl.py ./vault \
  --persons-dir contacts \
  --projects-dir work \
  --output ./knowledge.ttl

Parameters

Extraction Rules

Person Files

Location: {vault}/{persons-dir}/*.md

Filename Pattern: Name_Organization.md

Extracted Fields:

• Name (from YAML title or filename)
• Organization (from filename suffix)
• Tags (from YAML tags)
• Summary (from YAML summary)
• Contact info (from YAML contact)
• Last contact date (from YAML last_contact)

Project Files

Location: {vault}/{projects-dir}/*/, {vault}/{archives-dir}/*/

Folder Pattern: YYMM ProjectName or YYMMDD ProjectName

Extracted Fields:

• Project name
• Start date (from folder name)
• Tags
• Summary
• Status (active/archived)

Meetings

Pattern: ## YYYY.MM.DD or ## YYYY-MM-DD headings

Extracted Fields:

• Date
• Summary (content under heading)
• Topics (hashtags in content)
• Participants (from [[wikilinks]])

Relationships

From [[Wikilinks]]:

• Person → Person: :knows
• Person → Project: :involvedIn
• Meeting → Person: :participant
• Meeting → Project: :relatedTo

Output Schema

Classes

Properties

Example Output

Copy@prefix : <http://obsidian.local/ontology#> .
@prefix data: <http://obsidian.local/data#> .

data:John_Doe a :Person ;
    :name "John Doe"@en ;
    :affiliatedWith data:Acme_Corp ;
    :summary "Senior developer specializing in AI" ;
    :filePath "persons/John_Doe_Acme.md" .

data:Acme_Corp a :Organization ;
    :name "Acme Corp"@en .

data:John_Doe_meeting_0 a :Meeting ;
    :participant data:John_Doe ;
    :date "2024-01-15"^^xsd:date ;
    :summary "Project kickoff discussion" .

Dependencies

Copypip install rdflib pyyaml