diff --git a/main.py b/main.py
index f7aea04..3fd22d8 100644
--- a/main.py
+++ b/main.py
@@ -232,6 +232,12 @@ class InstanceCreate(BaseModel):
     port: int = 4646
     secret: str
 
+class InstanceUpdate(BaseModel):
+    name: str
+    ip: str
+    port: int = 4646
+    secret: Optional[str] = None
+
 def clean_secret(secret_input):
     secret_clean = secret_input.strip()
     if secret_clean.lower().startswith('otpauth://'):