diff --git a/src/logger.ts b/src/logger.ts
new file mode 100644
index 0000000..d857d1a
--- /dev/null
+++ b/src/logger.ts
@@ -0,0 +1,28 @@
+import pino from "pino";
+import { mkdirSync } from "node:fs";
+import { join } from "node:path";
+
+export function createLogger(logDir?: string): pino.Logger {
+  if (!logDir) {
+    return pino({ level: "info" });
+  }
+
+  mkdirSync(logDir, { recursive: true });
+
+  const transport = pino.transport({
+    targets: [
+      {
+        target: "pino/file",
+        options: { destination: 1 }, // stdout
+        level: "info",
+      },
+      {
+        target: "pino/file",
+        options: { destination: join(logDir, "bot.log"), mkdir: true },
+        level: "debug",
+      },
+    ],
+  });
+
+  return pino({ level: "debug" }, transport);
+}