[do not merge] json validation

website/docs/main-concepts.mdx

@@ -28,6 +28,12 @@ A _Feature Flag_ is a _Setting_ of type Bool.
 | Whole Number   | Integer      | Any whole number within the range of `Int32`.                                      |
 | Decimal Number | Double       | Any decimal number within the range of `double`.                                   |
 
+#### JSON validation for text settings
+
+For text settings, there is an additional option to require setting values to be valid JSON. When turned on, ConfigCat will only allow valid JSON values to be entered.
+
+However, please note that this means validation only. Your application will still get a string value, and you will need to parse it into JSON manually if necessary.
+
 ### Free-form values vs predefined variations
 
 ConfigCat supports two value-modes for feature flags:

website/docs/news.mdx

@@ -11,6 +11,18 @@ Here, you'll find all the latest updates, enhancements, and new features we've a
 
 {/* This page must be in sync with the news page on the Dashboard: https://github.com/configcat/app/blob/master/src/app/home-module/news/news.component.html */}
 
+## JSON validation for text settings
+
+#### Jul 15, 2026
+
+We implemented a new option for text settings that allows you to **require valid JSON values**.  
+
+This can be turned on for newly created text settings, and for existing ones as well, in the **Edit feature flag** dialog.
+
+When enabled, ConfigCat validates setting values before saving, ensuring that no invalid JSON is published.
+
+---
+
 ## Feature Flags for Startups: Meet the ConfigCat Startup Program
 
 #### Jun 17, 2026