diff --git a/src/lib/migrateData.js b/src/lib/migrateData.js
new file mode 100644
index 0000000..2fd842c
--- /dev/null
+++ b/src/lib/migrateData.js
@@ -0,0 +1,53 @@
+import dotenv from 'dotenv';
+import { createClient } from '@supabase/supabase-js';
+
+dotenv.config();
+
+const cloudUrl = process.env.CLOUD_SUPABASE_URL;
+const cloudKey = process.env.CLOUD_SUPABASE_SERVICE_ROLE_KEY || process.env.CLOUD_SUPABASE_ANON_KEY;
+const onpremUrl = process.env.ONPREM_SUPABASE_URL;
+const onpremKey = process.env.ONPREM_SUPABASE_SERVICE_ROLE_KEY || process.env.ONPREM_SUPABASE_ANON_KEY;
+
+if (!cloudUrl || !cloudKey || !onpremUrl || !onpremKey) {
+  console.error('환경 변수 설정 오류: CLOUD/ONPREM URL 또는 키가 누락되었습니다.');
+  process.exit(1);
+}
+
+const cloud = createClient(cloudUrl, cloudKey);
+const onprem = createClient(onpremUrl, onpremKey);
+const tables = ['users', 'accounts', 'transactions'];
+
+async function migrateTable(table) {
+  console.log(`Migrating table: ${table}`);
+  const { data, error } = await cloud.from(table).select('*');
+  if (error) {
+    if (error.code === '42P01') {
+      console.warn(`Table ${table} not found in Cloud DB, skipping.`);
+      return;
+    }
+    console.error(`Error fetching ${table}:`, error);
+    return;
+  }
+  if (!data.length) {
+    console.log(`${table} has no data to migrate.`);
+    return;
+  }
+  const { error: insertError } = await onprem.from(table).upsert(data);
+  if (insertError) {
+    console.error(`Error inserting into ${table}:`, insertError);
+  } else {
+    console.log(`Migrated ${data.length} rows into ${table}`);
+  }
+}
+
+async function main() {
+  for (const table of tables) {
+    await migrateTable(table);
+  }
+  console.log('Migration complete.');
+}
+
+main().catch(err => {
+  console.error('Migration failed:', err);
+  process.exit(1);
+});