docs(realtime): JWT claims can be accessed when authorising channels (supabase#38049)

Author: edgurgel

apps/docs/content/guides/realtime/authorization.mdx

@@ -50,13 +50,11 @@ Increased RLS complexity can impact database performance and connection time, le
 
 </Admonition>
 
-## Helper functions
-
-You can use the following helper functions when writing RLS policies:
+## Accessing request information
 
 ### `realtime.topic`
 
-Returns the Channel topic the user is attempting to connect to.
+You can use the `realtime.topic` helper function when writing RLS policies. It returns the Channel topic the user is attempting to connect to.
 
 ```sql
 create policy "authenticated can read all messages on topic"
@@ -68,6 +66,21 @@ using (
 );
 ```
 
+### JWT claims
+
+The user claims can be accessed using the `current_setting` function. The claims are available as a JSON object in the `request.jwt.claims` setting.
+
+```sql
+create policy "authenticated with supabase.io email can read all"
+on "realtime"."messages"
+for select
+to authenticated
+using (
+  -- Only users with the email claim ending with @supabase.io
+  (((current_setting('request.jwt.claims'))::json ->> 'email') ~~ '%@supabase.io')
+);
+```
+
 ## Examples
 
 The following examples use this schema:

apps/docs/content/guides/realtime/broadcast.mdx

@@ -811,7 +811,7 @@ The `realtime.send` function provides the most flexibility by allowing you to br
 
 ```sql
 SELECT realtime.send (
-	to_jsonb ('{}'::text), -- JSONB Payload
+	'{}'::jsonb, -- JSONB Payload
 	'event', -- Event name
 	'topic', -- Topic
 	FALSE -- Public / Private flag