Initial commit: Cortex — AI project memory & knowledge graph

SQLite-backed knowledge graph with CLI interface. Supports nodes (memory, component, task, decision) connected by typed edges, with hybrid search (BM25 + Ollama embeddings).

src/core/db.ts

@@ -0,0 +1,72 @@
+import Database from 'better-sqlite3';
+import path from 'path';
+import fs from 'fs';
+
+const SCHEMA = `
+CREATE TABLE IF NOT EXISTS nodes (
+  id TEXT PRIMARY KEY,
+  kind TEXT NOT NULL,
+  title TEXT NOT NULL,
+  content TEXT NOT NULL DEFAULT '',
+  status TEXT,
+  tags TEXT DEFAULT '[]',
+  metadata TEXT DEFAULT '{}',
+  embedding BLOB,
+  created_at INTEGER NOT NULL,
+  updated_at INTEGER NOT NULL,
+  is_stale INTEGER DEFAULT 0
+);
+
+CREATE TABLE IF NOT EXISTS edges (
+  id TEXT PRIMARY KEY,
+  from_id TEXT NOT NULL REFERENCES nodes(id) ON DELETE CASCADE,
+  to_id TEXT NOT NULL REFERENCES nodes(id) ON DELETE CASCADE,
+  type TEXT NOT NULL,
+  metadata TEXT DEFAULT '{}',
+  created_at INTEGER NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS node_tags (
+  node_id TEXT NOT NULL REFERENCES nodes(id) ON DELETE CASCADE,
+  tag TEXT NOT NULL,
+  PRIMARY KEY (node_id, tag)
+);
+
+CREATE INDEX IF NOT EXISTS idx_nodes_kind ON nodes(kind);
+CREATE INDEX IF NOT EXISTS idx_nodes_status ON nodes(status);
+CREATE INDEX IF NOT EXISTS idx_nodes_created ON nodes(created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_nodes_stale ON nodes(is_stale);
+CREATE INDEX IF NOT EXISTS idx_edges_from ON edges(from_id);
+CREATE INDEX IF NOT EXISTS idx_edges_to ON edges(to_id);
+CREATE INDEX IF NOT EXISTS idx_edges_type ON edges(type);
+CREATE INDEX IF NOT EXISTS idx_tags_tag ON node_tags(tag);
+`;
+
+let _db: Database.Database | null = null;
+
+export function getMemoryDir(): string {
+  return path.join(process.cwd(), '.memory');
+}
+
+export function getDb(): Database.Database {
+  if (_db) return _db;
+
+  const dir = getMemoryDir();
+  if (!fs.existsSync(dir)) {
+    fs.mkdirSync(dir, { recursive: true });
+  }
+
+  _db = new Database(path.join(dir, 'cortex.db'));
+  _db.pragma('journal_mode = WAL');
+  _db.pragma('foreign_keys = ON');
+  _db.exec(SCHEMA);
+
+  return _db;
+}
+
+export function closeDb(): void {
+  if (_db) {
+    _db.close();
+    _db = null;
+  }
+}