# Phase 004: Graph Intelligence
**Status**: Completed
**Start Date**: 2025-12-05
**Target Completion**: 2025-12-05
**Actual Completion**: 2025-12-05
**Owner**: Claude
## Objectives
- Build knowledge graph capabilities from wiki-link relationships
- Implement palace_links tool for backlink/outlink traversal
- Implement palace_orphans tool to find disconnected notes
- Implement palace_related tool to discover related content
- Enable graph-based knowledge discovery
## Prerequisites
- [x] Phase 001 completed
- [x] Phase 002 completed
- [x] Phase 003 completed (SQLite index with links table)
- [x] Wiki-link extraction working in index
- [x] Test vault configured via PALACE_VAULT_PATH
## Scope
### In Scope
- Graph service for link relationship management
- Backlink tracking and querying
- Outgoing link tracking
- Orphan note detection (no incoming/outgoing links)
- Related note discovery based on shared links
- Link depth traversal (multi-hop relationships)
- palace_links tool
- palace_orphans tool
- palace_related tool
### Out of Scope
- Auto-linking (Phase 5)
- Content similarity matching (future enhancement)
- Visual graph rendering (client responsibility)
## Tasks
### Setup
- [x] Create services/graph/ directory structure
- [x] Define graph data structures
### Development
- [x] Implement services/graph/links.ts
- [x] Extract outgoing links from note content
- [x] Resolve link targets to note paths
- [x] Handle broken/unresolved links
- [x] Cache link relationships (via SQLite index)
- [x] Implement services/graph/relationships.ts
- [x] Get backlinks (notes linking to target)
- [x] Get outlinks (notes target links to)
- [x] Multi-hop traversal (depth parameter)
- [x] Find common links between notes
- [x] Implement services/graph/index.ts barrel export
- [x] Implement tools/links.ts (palace_links)
- [x] Direction parameter (incoming, outgoing, both)
- [x] Depth parameter for multi-hop
- [x] Include resolved/unresolved status
- [x] Implement tools/orphans.ts (palace_orphans)
- [x] Find notes with no incoming links
- [x] Find notes with no outgoing links
- [x] Find completely isolated notes
- [x] Filter by path/type
- [x] Implement tools/related.ts (palace_related)
- [x] Find related by shared links
- [x] Find related by shared tags
- [x] Configurable relatedness method
- [x] Limit results
### Testing & Validation
- [x] Unit tests for link extraction
- [x] Unit tests for graph traversal
- [x] Integration tests with linked notes
- [x] Test orphan detection accuracy
- [x] Test multi-hop traversal
### Documentation
- [x] Update CLAUDE.md with new tools
- [x] Document graph query patterns
- [x] Add examples for common use cases
## Standards & References
- [CLAUDE.md](../../CLAUDE.md) - Project guidelines
- [Obsidian Palace MCP Spec](../obsidian-palace-mcp-spec.md) - Tool specifications
- [Obsidian Link Format](https://help.obsidian.md/Linking+notes+and+files/Internal+links)
## Technical Details
### Graph Data Structures
```typescript
interface GraphLink {
source: string; // Source note path
target: string; // Target note path (or title)
resolved: boolean; // Does target exist?
}
interface GraphNode {
path: string;
title: string;
incomingCount: number;
outgoingCount: number;
}
interface TraversalResult {
depth: number;
path: string[]; // Path from origin to this node
note: NoteMetadata;
}
```
### Files to Create
```
src/services/graph/
├── links.ts # Link extraction and resolution
├── relationships.ts # Graph traversal algorithms
└── index.ts # Barrel exports
src/tools/
├── links.ts # palace_links
├── orphans.ts # palace_orphans
└── related.ts # palace_related
```
### Tool Specifications
#### palace_links
```typescript
{
path: string; // Note to analyze
direction: 'incoming' | 'outgoing' | 'both'; // Link direction
depth: number; // Traversal depth (default: 1)
}
```
#### palace_orphans
```typescript
{
type: 'no_incoming' | 'no_outgoing' | 'isolated'; // Orphan type
path?: string; // Limit to directory
}
```
#### palace_related
```typescript
{
path: string; // Source note
method: 'links' | 'tags' | 'content'; // Relatedness method
limit: number; // Max results (default: 10)
}
```
## Testing & Quality Assurance
### Test Vault
Located at: `/Users/adamc/Documents/Claude Palace`
Create test notes with known link structures for validation.
### Test Coverage Requirements
- Unit tests: 80% coverage for graph services
- Integration tests: Complex link graphs
- Edge cases: Circular links, broken links, self-links
### Quality Checks
- [x] Code review completed
- [x] All tests passing (39 tests)
- [x] Linting passes
- [x] Documentation updated
- [x] No regressions in existing tools
## Acceptance Criteria
- [x] palace_links returns accurate backlinks and outlinks
- [x] Multi-hop traversal works correctly
- [x] palace_orphans identifies all orphan types
- [x] palace_related finds meaningfully related notes
- [x] Broken links are identified but don't cause errors
- [x] Performance acceptable for large graphs
- [x] Graph data stays in sync with index
## Risks & Mitigation
| Risk | Impact | Probability | Mitigation Strategy |
|------|--------|-------------|---------------------|
| Circular link infinite loops | High | Medium | Visited set tracking, max depth |
| Large graph memory usage | Medium | Low | Lazy loading, pagination |
| Stale graph data | Medium | Medium | Sync with file watcher events |
| Complex traversal performance | Medium | Medium | Index optimization, caching |
## Notes & Decisions
### Link Resolution Strategy
- Context: How to match [[link]] to actual notes
- Options:
1. Exact title match only
2. Case-insensitive match
3. Alias support
4. Fuzzy matching
- Decision: Implemented case-insensitive matching on title, path, and filename. Alias support can be added in future.
### Relatedness Scoring
- Context: How to rank related notes
- Options:
1. Shared link count
2. Jaccard similarity of links
3. Combined link + tag score
- Decision: Implemented Jaccard-like similarity for both links and tags. Combined scoring with configurable method (links, tags, or both).
