diff --git a/backend/main.py b/backend/main.py
index 71c7281..410b2e7 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -37,6 +37,25 @@ load_dotenv()
 # Create database tables
 models.Base.metadata.create_all(bind=engine)
 
+# ── Auto-migrate: add new columns if they don't exist yet ────────────────────
+def _run_startup_migrations():
+    """Idempotent column additions — safe to run on every deploy."""
+    statements = [
+        "ALTER TABLE events ADD COLUMN IF NOT EXISTS invitation_image_url TEXT;",
+        "ALTER TABLE events ADD COLUMN IF NOT EXISTS guest_form_fields TEXT;",
+        "ALTER TABLE guests_v2 ADD COLUMN IF NOT EXISTS companion_count INTEGER DEFAULT 0;",
+    ]
+    from sqlalchemy import text
+    with engine.connect() as conn:
+        for stmt in statements:
+            try:
+                conn.execute(text(stmt))
+            except Exception as e:
+                print(f"[startup migration] warning: {e}")
+        conn.commit()
+
+_run_startup_migrations()
+
 app = FastAPI(title="Multi-Event Invitation Management API")
 
 # Ensure uploads directory exists and serve it as static files