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description: "Core project conventions for Second Brain monorepo"
mode: always
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# Second Brain — Cursor Rules

Developer knowledge graph. pnpm monorepo, Turborepo, Node.js 22+, TypeScript 5.8+ strict, ESM only.

For full context, see @docs/architecture.md and @AGENTS.md.

## Stack
- SQLite (better-sqlite3) + Drizzle ORM + FTS5 + sqlite-vec
- Zod v4 for validation, ULIDs for IDs, ISO 8601 timestamps
- Vitest with in-memory SQLite for tests
- tsdown for builds, tsc for type-checking

## Rules
- ESM only. Named exports. Re-export from index.ts
- Use workspace imports: `@second-brain/core`, `@second-brain/types`
- No `any`. No path aliases. No UUIDs. No unix timestamps
- Namespace field on all entities/relations: 'personal' or project ID
- FTS5 triggers auto-maintain search index — never write to entities_fts
- Confidence decay is read-side only — never mutate stored confidence
- batchUpsert for bulk operations (merges observations/tags)