Implemented three new API endpoints for knowledge graph visualization:
1. GET /api/knowledge/graph - Full knowledge graph
- Returns all entries and links with optional filtering
- Supports filtering by tags, status, and node count limit
- Includes orphan detection (entries with no links)
2. GET /api/knowledge/graph/stats - Graph statistics
- Total entries and links counts
- Orphan entries detection
- Average links per entry
- Top 10 most connected entries
- Tag distribution across entries
3. GET /api/knowledge/graph/:slug - Entry-centered subgraph
- Returns graph centered on specific entry
- Supports depth parameter (1-5) for traversal distance
- Includes all connected nodes up to specified depth
New Files:
- apps/api/src/knowledge/graph.controller.ts
- apps/api/src/knowledge/graph.controller.spec.ts
Modified Files:
- apps/api/src/knowledge/dto/graph-query.dto.ts (added GraphFilterDto)
- apps/api/src/knowledge/entities/graph.entity.ts (extended with new types)
- apps/api/src/knowledge/services/graph.service.ts (added new methods)
- apps/api/src/knowledge/services/graph.service.spec.ts (added tests)
- apps/api/src/knowledge/knowledge.module.ts (registered controller)
- apps/api/src/knowledge/dto/index.ts (exported new DTOs)
- docs/scratchpads/71-graph-data-api.md (implementation notes)
Test Coverage: 21 tests (all passing)
- 14 service tests including orphan detection, filtering, statistics
- 7 controller tests for all three endpoints
Follows TDD principles with tests written before implementation.
All code quality gates passed (lint, typecheck, tests).
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Issues resolved:
- #68: pgvector Setup
* Added pgvector vector index migration for knowledge_embeddings
* Vector index uses HNSW algorithm with cosine distance
* Optimized for 1536-dimension OpenAI embeddings
- #69: Embedding Generation Pipeline
* Created EmbeddingService with OpenAI integration
* Automatic embedding generation on entry create/update
* Batch processing endpoint for existing entries
* Async generation to avoid blocking API responses
* Content preparation with title weighting
- #70: Semantic Search API
* POST /api/knowledge/search/semantic - pure vector search
* POST /api/knowledge/search/hybrid - RRF combined search
* POST /api/knowledge/embeddings/batch - batch generation
* Comprehensive test coverage
* Full documentation in docs/SEMANTIC_SEARCH.md
Technical details:
- Uses OpenAI text-embedding-3-small model (1536 dims)
- HNSW index for O(log n) similarity search
- Reciprocal Rank Fusion for hybrid search
- Graceful degradation when OpenAI not configured
- Async embedding generation for performance
Configuration:
- Added OPENAI_API_KEY to .env.example
- Optional feature - disabled if API key not set
- Falls back to keyword search in hybrid mode
Issue #73 - Entry-Centered Graph View:
- Added GET /api/knowledge/entries/:id/graph endpoint with depth parameter
- Returns entry + connected nodes with link relationships
- Created GraphService for graph traversal using BFS
- Added EntryGraphViewer component for frontend
- Integrated graph view tab into entry detail page
Issue #74 - Graph Statistics Dashboard:
- Added GET /api/knowledge/stats endpoint
- Returns overview stats (entries, tags, links by status)
- Includes most connected entries, recent activity, tag distribution
- Created StatsDashboard component with visual stats
- Added route at /knowledge/stats
Backend:
- GraphService: BFS-based graph traversal with configurable depth
- StatsService: Parallel queries for comprehensive statistics
- GraphQueryDto: Validation for depth parameter (1-5)
- Entity types for graph nodes/edges and statistics
- Unit tests for both services
Frontend:
- EntryGraphViewer: Entry-centered graph visualization
- StatsDashboard: Statistics overview with charts
- Graph view tab on entry detail page
- API client functions for new endpoints
- TypeScript strict typing throughout
- Create LinkResolutionService with workspace-scoped link resolution
- Resolve links by: exact title match, slug match, fuzzy title match
- Handle ambiguous matches (return null if multiple matches)
- Support batch link resolution with deduplication
- Comprehensive test suite with 19 tests, all passing
- 100% coverage of public methods
- Integrate service with KnowledgeModule
Closes#60 (KNOW-008)
- Add Tag DTOs (CreateTagDto, UpdateTagDto) with validation
- Implement TagsService with CRUD operations
- Add TagsController with authenticated endpoints
- Support automatic slug generation from tag names
- Add workspace isolation for tags
- Include entry count in tag responses
- Add findOrCreateTags method for entry creation/update
- Implement comprehensive test coverage (29 tests passing)
Endpoints:
- GET /api/knowledge/tags - List workspace tags
- POST /api/knowledge/tags - Create tag
- GET /api/knowledge/tags/:slug - Get tag by slug
- PUT /api/knowledge/tags/:slug - Update tag
- DELETE /api/knowledge/tags/:slug - Delete tag
- GET /api/knowledge/tags/:slug/entries - List entries with tag
Related: KNOW-003
