fix: thread creation payload

CHANGELOG.md

@@ -158,6 +158,8 @@ These changes are available on the `master` branch, but have not yet been releas
   `Webhook` class. ([#2156](https://github.com/Pycord-Development/pycord/pull/2156))
 - Fixed `ScheduledEvent.creator_id` returning `str` instead of `int`.
   ([#2162](https://github.com/Pycord-Development/pycord/pull/2162))
+- Fixed initial message inside of the create thread payload sending legacy beta payload.
+  ([#2191](https://github.com/Pycord-Development/pycord/pull/2191))
 
 ## [2.4.1] - 2023-03-20
 

discord/http.py

@@ -1183,37 +1183,42 @@ def start_forum_thread(
             "auto_archive_duration": auto_archive_duration,
             "invitable": invitable,
         }
-        if content:
-            payload["content"] = content
 
         if applied_tags:
             payload["applied_tags"] = applied_tags
 
+        message = {}
+
+        if content:
+            message["content"] = content
+
         if embed:
-            payload["embeds"] = [embed]
+            message["embeds"] = [embed]
 
         if embeds:
-            payload["embeds"] = embeds
+            message["embeds"] = embeds
 
         if nonce:
-            payload["nonce"] = nonce
+            message["nonce"] = nonce
 
         if allowed_mentions:
-            payload["allowed_mentions"] = allowed_mentions
+            message["allowed_mentions"] = allowed_mentions
 
         if components:
-            payload["components"] = components
+            message["components"] = components
 
         if stickers:
-            payload["sticker_ids"] = stickers
+            message["sticker_ids"] = stickers
 
         if rate_limit_per_user:
-            payload["rate_limit_per_user"] = rate_limit_per_user
+            message["rate_limit_per_user"] = rate_limit_per_user
+
+        if message != {}:
+            payload["message"] = message
 
-        # TODO: Once supported by API, remove has_message=true query parameter
         route = Route(
             "POST",
-            "/channels/{channel_id}/threads?has_message=true",
+            "/channels/{channel_id}/threads",
             channel_id=channel_id,
         )