diff --git a/src/data/database.test.ts b/src/data/database.test.ts
new file mode 100644
index 0000000..cdf026e
--- /dev/null
+++ b/src/data/database.test.ts
@@ -0,0 +1,97 @@
+import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { createDatabase, type BotDatabase, type BotInstance } from "./database.js";
+
+describe("database", () => {
+  let botDb: BotDatabase;
+
+  beforeEach(() => {
+    botDb = createDatabase(":memory:");
+  });
+
+  afterEach(() => {
+    botDb.close();
+  });
+
+  it("creates 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("play_history");
+    expect(names).toContain("bot_instances");
+  });
+
+  it("records and retrieves play history", () => {
+    botDb.addPlayHistory({
+      botId: "bot1",
+      songId: "song1",
+      songName: "Test Song",
+      artist: "Test Artist",
+      album: "Test Album",
+      platform: "netease",
+      coverUrl: "https://example.com/cover.jpg",
+      playedAt: new Date().toISOString(),
+    });
+
+    botDb.addPlayHistory({
+      botId: "bot1",
+      songId: "song2",
+      songName: "Another Song",
+      artist: "Another Artist",
+      album: "Another Album",
+      platform: "qq",
+      coverUrl: "https://example.com/cover2.jpg",
+      playedAt: new Date().toISOString(),
+    });
+
+    const history = botDb.getPlayHistory("bot1", 10);
+    expect(history).toHaveLength(2);
+    expect(history[0].songName).toBe("Another Song");
+    expect(history[1].songName).toBe("Test Song");
+  });
+
+  it("saves and loads bot instances", () => {
+    const instance: BotInstance = {
+      id: "bot1",
+      name: "Music Bot",
+      serverAddress: "localhost",
+      serverPort: 9987,
+      nickname: "MusicBot",
+      defaultChannel: "Music",
+      channelPassword: "",
+      autoStart: true,
+    };
+
+    botDb.saveBotInstance(instance);
+    const instances = botDb.getBotInstances();
+    expect(instances).toHaveLength(1);
+    expect(instances[0]).toEqual(instance);
+    expect(instances[0].autoStart).toBe(true);
+
+    // Test upsert
+    botDb.saveBotInstance({ ...instance, nickname: "UpdatedBot", autoStart: false });
+    const updated = botDb.getBotInstances();
+    expect(updated).toHaveLength(1);
+    expect(updated[0].nickname).toBe("UpdatedBot");
+    expect(updated[0].autoStart).toBe(false);
+  });
+
+  it("deletes bot instance", () => {
+    botDb.saveBotInstance({
+      id: "bot1",
+      name: "Music Bot",
+      serverAddress: "localhost",
+      serverPort: 9987,
+      nickname: "MusicBot",
+      defaultChannel: "Music",
+      channelPassword: "",
+      autoStart: false,
+    });
+
+    expect(botDb.deleteBotInstance("bot1")).toBe(true);
+    expect(botDb.getBotInstances()).toHaveLength(0);
+    expect(botDb.deleteBotInstance("nonexistent")).toBe(false);
+  });
+});
diff --git a/src/data/database.ts b/src/data/database.ts
new file mode 100644
index 0000000..1de1356
--- /dev/null
+++ b/src/data/database.ts
@@ -0,0 +1,128 @@
+import Database from "better-sqlite3";
+
+export interface PlayHistoryRecord {
+  id?: number;
+  botId: string;
+  songId: string;
+  songName: string;
+  artist: string;
+  album: string;
+  platform: string;
+  coverUrl: string;
+  playedAt: string;
+}
+
+export interface BotInstance {
+  id: string;
+  name: string;
+  serverAddress: string;
+  serverPort: number;
+  nickname: string;
+  defaultChannel: string;
+  channelPassword: string;
+  autoStart: boolean;
+}
+
+export interface BotDatabase {
+  db: Database.Database;
+  addPlayHistory(record: Omit<PlayHistoryRecord, "id">): void;
+  getPlayHistory(botId: string, limit: number): PlayHistoryRecord[];
+  saveBotInstance(instance: BotInstance): void;
+  getBotInstances(): BotInstance[];
+  deleteBotInstance(id: string): boolean;
+  close(): void;
+}
+
+function initTables(db: Database.Database): void {
+  db.exec(`
+    CREATE TABLE IF NOT EXISTS play_history (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      botId TEXT NOT NULL,
+      songId TEXT NOT NULL,
+      songName TEXT NOT NULL,
+      artist TEXT NOT NULL,
+      album TEXT NOT NULL,
+      platform TEXT NOT NULL,
+      coverUrl TEXT NOT NULL,
+      playedAt TEXT NOT NULL
+    );
+
+    CREATE TABLE IF NOT EXISTS bot_instances (
+      id TEXT PRIMARY KEY,
+      name TEXT NOT NULL,
+      serverAddress TEXT NOT NULL,
+      serverPort INTEGER NOT NULL,
+      nickname TEXT NOT NULL,
+      defaultChannel TEXT NOT NULL,
+      channelPassword TEXT NOT NULL,
+      autoStart INTEGER NOT NULL DEFAULT 0
+    );
+  `);
+}
+
+export function createDatabase(dbPath: string): BotDatabase {
+  const db = new Database(dbPath);
+  db.pragma("journal_mode = WAL");
+  initTables(db);
+
+  const insertHistory = db.prepare(`
+    INSERT INTO play_history (botId, songId, songName, artist, album, platform, coverUrl, playedAt)
+    VALUES (@botId, @songId, @songName, @artist, @album, @platform, @coverUrl, @playedAt)
+  `);
+
+  const selectHistory = db.prepare(`
+    SELECT * FROM play_history WHERE botId = ? ORDER BY id DESC LIMIT ?
+  `);
+
+  const upsertInstance = db.prepare(`
+    INSERT INTO bot_instances (id, name, serverAddress, serverPort, nickname, defaultChannel, channelPassword, autoStart)
+    VALUES (@id, @name, @serverAddress, @serverPort, @nickname, @defaultChannel, @channelPassword, @autoStart)
+    ON CONFLICT(id) DO UPDATE SET
+      name = excluded.name,
+      serverAddress = excluded.serverAddress,
+      serverPort = excluded.serverPort,
+      nickname = excluded.nickname,
+      defaultChannel = excluded.defaultChannel,
+      channelPassword = excluded.channelPassword,
+      autoStart = excluded.autoStart
+  `);
+
+  const selectInstances = db.prepare(`SELECT * FROM bot_instances`);
+
+  const deleteInstance = db.prepare(`DELETE FROM bot_instances WHERE id = ?`);
+
+  return {
+    db,
+
+    addPlayHistory(record) {
+      insertHistory.run(record);
+    },
+
+    getPlayHistory(botId, limit) {
+      return selectHistory.all(botId, limit) as PlayHistoryRecord[];
+    },
+
+    saveBotInstance(instance) {
+      upsertInstance.run({
+        ...instance,
+        autoStart: instance.autoStart ? 1 : 0,
+      });
+    },
+
+    getBotInstances() {
+      const rows = selectInstances.all() as Array<
+        Omit<BotInstance, "autoStart"> & { autoStart: number }
+      >;
+      return rows.map((r) => ({ ...r, autoStart: r.autoStart === 1 }));
+    },
+
+    deleteBotInstance(id) {
+      const result = deleteInstance.run(id);
+      return result.changes > 0;
+    },
+
+    close() {
+      db.close();
+    },
+  };
+}