# ontology-engine

> Convert PARA-structured markdown vault to RDF/TTL knowledge graph. Extract items, meetings, and relationships into semantic triples.

- Author: hwaa
- Repository: DinN0000/knowledge-graph
- Version: 20260209131658
- Stars: 0
- Forks: 0
- Last Updated: 2026-02-09
- Source: https://github.com/DinN0000/knowledge-graph
- Web: https://mule.run/skillshub/@@DinN0000/knowledge-graph~ontology-engine:20260209131658

---

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

# Ontology Engine (PARA)

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

## Usage

### Build Knowledge Graph

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

### With Custom Folders

```bash
source .venv/bin/activate && \
python .claude/skills/ontology-engine/scripts/vault_to_ttl.py ./vault \
  --inbox-dir 0_Inbox \
  --project-dir 1_Project \
  --area-dir 2_Area \
  --resource-dir 3_Resource \
  --archive-dir 4_Archive \
  --output ./knowledge.ttl
```

## Parameters

| Parameter | Default | Description |
|-----------|---------|-------------|
| `vault_path` | Required | Root vault directory |
| `--output` | `knowledge.ttl` | Output TTL file |
| `--inbox-dir` | `0_Inbox` | Inbox folder |
| `--project-dir` | `1_Project` | Project folder |
| `--area-dir` | `2_Area` | Area folder |
| `--resource-dir` | `3_Resource` | Resource folder |
| `--archive-dir` | `4_Archive` | Archive folder |

## PARA Folder Structure

| Folder | Type | Contents |
|--------|------|----------|
| `0_Inbox/` | Flat | `*.md` files |
| `1_Project/` | Nested | `YYMM ProjectName/` subfolders |
| `2_Area/` | Flat | `*.md` files |
| `3_Resource/` | Flat | `*.md` files |
| `4_Archive/` | Nested | `YYMM ProjectName/` subfolders |

## Extraction Rules

### Item Files

**Location**: All PARA folders

**Extracted Fields**:
- Name (from YAML `title` or filename)
- Tags (from YAML `tags`)
- Summary (from YAML `summary`)
- Date (from YAML `date` or folder name)
- Status (from YAML `status`)

### Project/Archive Folders

**Folder Pattern**: `YYMM ProjectName` or `YYMMDD ProjectName`

**Extracted Fields**:
- Project name (from folder name)
- Start date (from folder name)
- Tags (aggregated from files)
- Summary (from first file)
- Status (archived for Archive folder)

### Meetings

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

**Extracted Fields**:
- Date
- Summary (content under heading)
- Topics (hashtags in content)
- Source item

### Relationships

**From [[Wikilinks]]**:
- Item → Item: `:relatedTo`
- Meeting → Item: `:sourceItem`
- Meeting → Topic: `:hasTopic`

## Output Schema

### Classes

| Class | Description |
|-------|-------------|
| `:Item` | Note item from any PARA folder |
| `:PARAFolder` | PARA folder (inbox, project, area, resource, archive) |
| `:Meeting` | Meeting, call, or interaction |
| `:Topic` | Discussion topic |

### Properties

| Property | Domain | Range |
|----------|--------|-------|
| `:name` | Any | string |
| `:date` | Meeting/Item | date |
| `:summary` | Any | string |
| `:filePath` | Item/PARAFolder | string |
| `:tag` | Item | string |
| `:inFolder` | Item | PARAFolder |
| `:paraType` | PARAFolder | string |
| `:relatedTo` | Item | Item |
| `:hasStatus` | Item | string |
| `:sourceItem` | Meeting | Item |
| `:hasTopic` | Meeting | Topic |

## Example Output

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

data:folder_1_Project a :PARAFolder ;
    :name "1_Project" ;
    :paraType "project" .

data:item_AI_Platform a :Item ;
    :name "AI Platform" ;
    :inFolder data:folder_1_Project ;
    :summary "AI automation platform development" ;
    :date "2024-01-15"^^xsd:date ;
    :hasStatus "active" .

data:AI_Platform_meeting_0 a :Meeting ;
    :sourceItem data:item_AI_Platform ;
    :date "2024-01-15"^^xsd:date ;
    :summary "Project kickoff" .
```

## Dependencies

```bash
pip install rdflib pyyaml
```