diff --git a/backend/src/services/app-connection/render/render-connection-schema.ts b/backend/src/services/app-connection/render/render-connection-schema.ts
index 6224b471e..77cc46714 100644
--- a/backend/src/services/app-connection/render/render-connection-schema.ts
+++ b/backend/src/services/app-connection/render/render-connection-schema.ts
@@ -11,7 +11,7 @@ import {
 import { RenderConnectionMethod } from "./render-connection-enums";
 
 export const RenderConnectionApiKeyCredentialsSchema = z.object({
-  apiKey: z.string().trim().min(1, "API key required")
+  apiKey: z.string().trim().min(1, "API key required").max(256, "API key cannot exceed 256 characters")
 });
 
 const BaseRenderConnectionSchema = BaseAppConnectionSchema.extend({ app: z.literal(AppConnection.Render) });