Note Graph View API

[ElioNeto]

Note Graph View API

Build an API endpoint that assembles a graph representation of note connections (links and backlinks) for visualization in the frontend graph view.

Graph Data Structure

Return a JSON structure consumable by D3.js force layout or vis.js:

{
  "nodes": [
    { "id": "note-path", "label": "Display Name", "group": "tag-group", "size": 5 }
  ],
  "edges": [
    { "source": "from-path", "target": "to-path", "weight": 1 }
  ]
}

API Endpoint

GET /notes/{path}/graph?depth=1&include_tags=true

• depth: Number of hops to traverse (default: 1, max: 3)
• include_tags: Whether to include tag-based edges
• Returns JSON graph structure

Implementation

Use existing infrastructure:

• NoteIndex::get_backlinks() and NoteIndex::get_forward_links() for edges
• TagIndex::search_by_tag() for tag grouping
• Engine::search_prefix("note:") to check which paths exist

Graph Assembly Algorithm

1. Start with the target note as root node
2. For each depth level:
   • Fetch forward links and backlinks for each node at current frontier
   • Add new nodes and edges to the graph
   • Deduplicate by node ID
3. Apply filters (tag, path prefix, max nodes)
4. Return serialized JSON

Performance Requirements

• Depth-1 graph for 50 connected notes: < 50ms
• Depth-2 graph for 200 connected notes: < 200ms
• Maximum 500 nodes per response

Acceptance Criteria

• Graph endpoint returns valid D3.js-compatible JSON
• Depth parameter controls traversal correctly
• Circular links do not cause infinite loops
• Tag filtering works (only show notes with specific tag)
• Non-existent notes return 404
• Unit tests for graph assembly logic
• Integration test with REST API

Parent Epic

#275

[ElioNeto]

Resolved by commit 48dd088 in branch feat/notes-engine-v2.

Implementation:

• Note Graph View API #280 — Integrated into the notes engine and REST API layer.

To create a PR manually:

gh pr create --base main --head feat/notes-engine-v2

Or via the web: https://github.com/ElioNeto/ApexStore/pull/new/feat/notes-engine-v2