Windsurf rules

1# Second Brain — Windsurf Rules
2 
3## Project Overview
4 
5Developer knowledge graph — pnpm monorepo with Turborepo. Node.js 22+, TypeScript 5.8+ strict mode, ESM only.
6 
7For full architecture: see docs/architecture.md
8For agent instructions: see AGENTS.md
9 
10## Tech Stack
11 
12- Runtime: Node.js 22+, ESM only ("type": "module")
13- Language: TypeScript 5.8+ strict mode
14- Database: SQLite (better-sqlite3) + Drizzle ORM, WAL mode
15- Search: FTS5 (BM25) + sqlite-vec (cosine KNN), Reciprocal Rank Fusion
16- Validation: Zod v4
17- Testing: Vitest, in-memory SQLite
18- Build: tsdown (ESM), tsc (type-check)
19- Frontend: React 19, Zustand, Cytoscape.js, Tailwind CSS, Radix UI
20- Sync: Yjs CRDTs via Hocuspocus relay
21- IDs: ULIDs (ulidx). Never UUID
22- Timestamps: ISO 8601 strings. Never unix timestamps
23 
24## Monorepo
25 
26packages/types      — Shared TypeScript types
27packages/core       — Knowledge graph engine (Brain class in src/brain.ts)
28packages/collectors — Data collectors + streaming providers
29packages/ingestion  — LLM extraction + embedding pipeline
30packages/sync       — Yjs CRDT sync bridge
31packages/mcp-server — MCP tools (32 tools, stdio + HTTP)
32apps/server         — Express 5 REST API + WebSocket (port 7430)
33apps/ui             — React 19 + Cytoscape.js (port 5173)
34apps/relay          — Hocuspocus CRDT relay (port 7421)
35tools/cli           — brain CLI (Commander.js)
36 
37## Commands
38 
39pnpm install, pnpm build, pnpm test, pnpm check-types, pnpm dev
40 
41## Coding Rules
42 
43### Always
44- ESM only. Named exports. Re-export from index.ts
45- Use workspace imports: @second-brain/core, @second-brain/types
46- Zod schemas for all external input validation
47- ULIDs for IDs (via ulidx)
48- ISO 8601 for timestamps
49- Namespace field on all entities/relations
50- In-memory SQLite for tests
51- Try-catch with descriptive errors
52- batchUpsert for bulk operations
53 
54### Never
55- Use `any` type
56- Use path aliases
57- Use UUIDs
58- Use unix timestamps or Date objects in storage
59- Write to entities_fts directly (auto-maintained via triggers)
60- Mutate stored confidence (decay is read-side only)
61- Sync 'personal' namespace
62- Import from package internals (use public API)
63 
64## Backend Patterns
65 
66- Drizzle ORM for queries (schema in packages/core/src/schema/)
67- Brain class is main facade (packages/core/src/brain.ts)
68- Relations: unique constraint on (sourceId, targetId, type)
69- Use createOrGet for idempotent relations
70- WebSocket broadcast after mutations
71- MCP tools: packages/mcp-server/src/tools/
72 
73## Frontend Patterns
74 
75- React 19 functional components
76- Zustand stores (one per feature in apps/ui/src/store/)
77- Cytoscape.js with diff-based rendering
78- Tailwind dark theme (zinc-950 bg)
79- REST client: apps/ui/src/lib/api.ts
80- WebSocket: apps/ui/src/lib/ws.ts (auto-reconnect)
81- HashRouter (React Router 7)
82 
83## Testing
84 
85- Vitest with globals (no imports for describe/it/expect)
86- In-memory SQLite for all DB tests
87- Co-located: __tests__/*.test.ts
88- Use Brain class directly (not HTTP)
89- Test happy path + error cases
90 
91## Data Model
92 
93Entity types (15): concept, decision, pattern, person, file, symbol, event, tool, fact, conversation, reference, implementation, pull_request, merge_request, branch
94 
95Relation types (20): relates_to, depends_on, implements, supersedes, contradicts, derived_from, authored_by, decided_in, uses, tests, contains, co_changes_with, preceded_by, blocks, reviewed_by, merged_in_mr, merged_in_pr, touches_file, owns, parallel_with
96 
97## Documentation
98 
99- docs/architecture.md — Full technical architecture
100- docs/getting-started.md — Usage guide
101- docs/api-reference.md — REST API + MCP + CLI reference
102- AGENTS.md — Detailed agent instructions
103