diff --git a/src/Plugins/BotSharp.Plugin.DeepSeekAI/Providers/Chat/ChatCompletionProvider.cs b/src/Plugins/BotSharp.Plugin.DeepSeekAI/Providers/Chat/ChatCompletionProvider.cs
index 11a91207..54cdfc51 100644
--- a/src/Plugins/BotSharp.Plugin.DeepSeekAI/Providers/Chat/ChatCompletionProvider.cs
+++ b/src/Plugins/BotSharp.Plugin.DeepSeekAI/Providers/Chat/ChatCompletionProvider.cs
@@ -210,19 +210,23 @@ public class ChatCompletionProvider : IChatCompletion
     {
         var client = ProviderHelper.GetClient(Provider, _model, _services);
         var chatClient = client.GetChatClient(_model);
-        var (prompt, messages, options) = PrepareOptions(agent, conversations);
 
         var hub = _services.GetRequiredService<MessageHub<HubObserveData<RoleDialogModel>>>();
         var conv = _services.GetRequiredService<IConversationService>();
         var messageId = conversations.LastOrDefault()?.MessageId ?? string.Empty;
 
+        // Before chat completion hooks MUST run before the provider builds its message list:
+        // a hook that mutates `conversations` (mid-turn user injection, the request-size budget)
+        // would otherwise only take effect on the NEXT call, so the very request it is meant to
+        // shrink would still be sent oversized.
         var contentHooks = _services.GetHooks<IContentGeneratingHook>(agent.Id);
-        // Before chat completion hook
         foreach (var hook in contentHooks)
         {
             await hook.BeforeGenerating(agent, conversations);
         }
 
+        var (prompt, messages, options) = PrepareOptions(agent, conversations);
+
         hub.Push(new()
         {
             EventName = ChatEvent.BeforeReceiveLlmStreamMessage,
diff --git a/src/Plugins/BotSharp.Plugin.OpenAI/Providers/Chat/ChatCompletionProvider.cs b/src/Plugins/BotSharp.Plugin.OpenAI/Providers/Chat/ChatCompletionProvider.cs
index ab60d87d..111208e9 100644
--- a/src/Plugins/BotSharp.Plugin.OpenAI/Providers/Chat/ChatCompletionProvider.cs
+++ b/src/Plugins/BotSharp.Plugin.OpenAI/Providers/Chat/ChatCompletionProvider.cs
@@ -203,19 +203,23 @@ public class ChatCompletionProvider : IChatCompletion
     {
         var client = ProviderHelper.GetClient(Provider, _model, _services);
         var chatClient = client.GetChatClient(_model);
-        var (prompt, messages, options) = PrepareOptions(agent, conversations);
 
         var hub = _services.GetRequiredService<MessageHub<HubObserveData<RoleDialogModel>>>();
         var conv = _services.GetRequiredService<IConversationService>();
         var messageId = conversations.LastOrDefault()?.MessageId ?? string.Empty;
 
+        // Before chat completion hooks MUST run before the provider builds its message list: a hook
+        // that mutates `conversations` (mid-turn user injection, the request-size budget) would
+        // otherwise only take effect on the NEXT call, so the very request it is meant to shrink
+        // would still be sent oversized.
         var contentHooks = _services.GetHooks<IContentGeneratingHook>(agent.Id);
-        // Before chat completion hook
         foreach (var hook in contentHooks)
         {
             await hook.BeforeGenerating(agent, conversations);
         }
 
+        var (prompt, messages, options) = PrepareOptions(agent, conversations);
+
         hub.Push(new()
         {
             EventName = ChatEvent.BeforeReceiveLlmStreamMessage,