diff --git a/src/data/database.test.ts b/src/data/database.test.ts
index de49541..ad32b43 100644
--- a/src/data/database.test.ts
+++ b/src/data/database.test.ts
@@ -23,6 +23,23 @@ describe("database", () => {
     expect(names).toContain("bot_instances");
   });
 
+  it("creates users and sessions tables on init", () => {
+    const tables = botDb.db
+      .prepare("SELECT name FROM sqlite_master WHERE type='table' ORDER BY name")
+      .all() as Array<{ name: string }>;
+    const names = tables.map((t) => t.name);
+    expect(names).toContain("users");
+    expect(names).toContain("sessions");
+
+    const userCols = botDb.db.prepare("PRAGMA table_info(users)").all() as Array<{ name: string }>;
+    const userColNames = userCols.map((c) => c.name).sort();
+    expect(userColNames).toEqual(["createdAt", "id", "passwordHash", "updatedAt", "username"]);
+
+    const sessionCols = botDb.db.prepare("PRAGMA table_info(sessions)").all() as Array<{ name: string }>;
+    const sessionColNames = sessionCols.map((c) => c.name).sort();
+    expect(sessionColNames).toEqual(["createdAt", "expiresAt", "id", "lastSeenAt", "userId"]);
+  });
+
   it("records and retrieves play history", () => {
     botDb.addPlayHistory({
       botId: "bot1",
diff --git a/src/data/database.ts b/src/data/database.ts
index fdcdb8f..7dd79da 100644
--- a/src/data/database.ts
+++ b/src/data/database.ts
@@ -127,12 +127,33 @@ function initTables(db: Database.Database): void {
       serverPassword TEXT NOT NULL DEFAULT '',
       identity TEXT
     );
+
+    CREATE TABLE IF NOT EXISTS users (
+      id TEXT PRIMARY KEY,
+      username TEXT NOT NULL UNIQUE COLLATE NOCASE,
+      passwordHash TEXT NOT NULL,
+      createdAt INTEGER NOT NULL,
+      updatedAt INTEGER NOT NULL
+    );
+
+    CREATE TABLE IF NOT EXISTS sessions (
+      id TEXT PRIMARY KEY,
+      userId TEXT NOT NULL,
+      createdAt INTEGER NOT NULL,
+      expiresAt INTEGER NOT NULL,
+      lastSeenAt INTEGER NOT NULL,
+      FOREIGN KEY (userId) REFERENCES users(id) ON DELETE CASCADE
+    );
+
+    CREATE INDEX IF NOT EXISTS idx_sessions_userId ON sessions(userId);
+    CREATE INDEX IF NOT EXISTS idx_sessions_expiresAt ON sessions(expiresAt);
   `);
 }
 
 export function createDatabase(dbPath: string): BotDatabase {
   const db = new Database(dbPath);
   db.pragma("journal_mode = WAL");
+  db.pragma("foreign_keys = ON");
   initTables(db);
   migrateSchema(db);