From ab9f3c022047f4c41228854dac14ad344796103a Mon Sep 17 00:00:00 2001
From: Glen Maddern <glen@glenmaddern.com>
Date: Tue, 24 Jun 2025 17:53:12 +1000
Subject: [PATCH] fix: Capture reasoning events during streaming instead of
 from result

- Add back reasoning variable to track content during streaming
- Handle reasoning events from extractReasoningMiddleware in stream processing
- Build up reasoning content from individual reasoning textDelta events
- Remove dependency on result.reasoning which wasn't being populated
- Add reasoning to assistant message after stream completes

The logs showed reasoning events were coming through correctly but we
weren't capturing them. This fixes the issue by collecting reasoning
content during streaming as the events arrive.
---
 .../chat-ui/src/hooks/useStreamResponse.ts    | 28 +++++++------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/examples/chat-ui/src/hooks/useStreamResponse.ts b/examples/chat-ui/src/hooks/useStreamResponse.ts
index 7632f7e..60165af 100644
--- a/examples/chat-ui/src/hooks/useStreamResponse.ts
+++ b/examples/chat-ui/src/hooks/useStreamResponse.ts
@@ -133,6 +133,7 @@ export const useStreamResponse = ({
 
     const streamResponse = async (messages: Message[]) => {
         let aiResponse = ''
+        let reasoning = ''
         let assistantMessageIndex = -1 // Track the index of our assistant message
         let assistantMessageCreated = false // Track if we've created the assistant message yet
 
@@ -197,7 +198,10 @@ export const useStreamResponse = ({
                 try {
                     debugLog(`[useStreamResponse] Full stream event:`, event.type, event)
 
-                    if (event.type === 'tool-call') {
+                    if (event.type === 'reasoning') {
+                        debugLog(`[useStreamResponse] Reasoning event:`, event)
+                        reasoning += event.textDelta || ''
+                    } else if (event.type === 'tool-call') {
                         const eventKey = `tool-call-${event.toolCallId}`
                         if (processedEvents.has(eventKey)) {
                             debugLog(`[useStreamResponse] Skipping duplicate tool call:`, eventKey)
@@ -314,29 +318,17 @@ export const useStreamResponse = ({
             debugLog(`[useStreamResponse] Finished processing full stream. Final response length: ${aiResponse.length}`)
             debugLog(`[useStreamResponse] Final aiResponse content:`, JSON.stringify(aiResponse))
             
-            // Extract reasoning from the result after streaming completes
-            const finalReasoning = await result.reasoning
-            const finalText = await result.text
-            debugLog(`[useStreamResponse] Final result.text:`, JSON.stringify(finalText))
-            
-            if (assistantMessageCreated) {
+            // Add reasoning to the final message if we collected any
+            if (reasoning && assistantMessageCreated) {
+                debugLog(`[useStreamResponse] Adding collected reasoning:`, reasoning.substring(0, 100))
                 setConversations((prev) => {
                     const updated = [...prev]
                     const conv = updated.find((c) => c.id === conversationId)
                     if (conv && assistantMessageIndex >= 0) {
                         const assistantMessage = conv.messages[assistantMessageIndex]
                         if (assistantMessage && hasContent(assistantMessage) && assistantMessage.role === 'assistant') {
-                            // Use the final cleaned text from the result instead of our tracked aiResponse
-                            if (finalText && supportsReasoning(selectedModel)) {
-                                assistantMessage.content = finalText
-                                debugLog(`[useStreamResponse] Updated content with cleaned result.text`)
-                            }
-                            
-                            if (finalReasoning) {
-                                assistantMessage.reasoning = finalReasoning
-                                debugLog(`[useStreamResponse] Added reasoning to assistant message at index ${assistantMessageIndex}`)
-                            }
-                            debugLog(`[useStreamResponse] Final message content:`, JSON.stringify(assistantMessage.content))
+                            assistantMessage.reasoning = reasoning
+                            debugLog(`[useStreamResponse] Added reasoning to assistant message at index ${assistantMessageIndex}`)
                         }
                     }
                     return updated