diff --git a/backend/functions/letta_agents.py b/backend/functions/letta_agents.py
index 580c12b51..d63993c7a 100644
--- a/backend/functions/letta_agents.py
+++ b/backend/functions/letta_agents.py
@@ -141,12 +141,17 @@ class Pipe:
         return "".join(content_parts) if content_parts else "No response"
 
     def _stream_response(self, client, agent_id: str, messages: list) -> Generator:
-        """Stream response from Letta agent with tool call support."""
+        """Stream response from Letta agent with tool call and reasoning support."""
         import html
+        import time
 
         # Track tool calls: {tool_call_id: {"name": str, "arguments": str}}
         tool_calls = {}
 
+        # Track reasoning: accumulate content and emit when complete
+        reasoning_content = ""
+        reasoning_start = None
+
         with client.agents.messages.stream(
             agent_id=agent_id,
             messages=messages,
@@ -155,7 +160,23 @@ class Pipe:
             for chunk in stream:
                 msg_type = getattr(chunk, 'message_type', None)
 
-                if msg_type == 'tool_call_message':
+                # Emit accumulated reasoning when transitioning to non-reasoning message
+                if reasoning_content and msg_type != 'reasoning_message':
+                    duration = int(time.time() - reasoning_start) if reasoning_start else 0
+                    yield f'<details type="reasoning" done="true" duration="{duration}">\n'
+                    yield f'{html.escape(reasoning_content)}\n'
+                    yield '</details>\n\n'
+                    reasoning_content = ""
+                    reasoning_start = None
+
+                if msg_type == 'reasoning_message':
+                    reasoning = getattr(chunk, 'reasoning', '')
+                    if reasoning:
+                        if reasoning_start is None:
+                            reasoning_start = time.time()
+                        reasoning_content += reasoning
+
+                elif msg_type == 'tool_call_message':
                     # Handle tool call chunks - accumulate but don't emit yet
                     tool_call = getattr(chunk, 'tool_call', None)
                     if tool_call:
@@ -200,3 +221,10 @@ class Pipe:
                     # Stream assistant content
                     if hasattr(chunk, 'content') and chunk.content:
                         yield chunk.content
+
+        # Handle case where reasoning was the last message
+        if reasoning_content:
+            duration = int(time.time() - reasoning_start) if reasoning_start else 0
+            yield f'<details type="reasoning" done="true" duration="{duration}">\n'
+            yield f'{html.escape(reasoning_content)}\n'
+            yield '</details>\n\n'
diff --git a/src/lib/components/common/Collapsible.svelte b/src/lib/components/common/Collapsible.svelte
index 8f788c6d8..4df06fa33 100644
--- a/src/lib/components/common/Collapsible.svelte
+++ b/src/lib/components/common/Collapsible.svelte
@@ -246,18 +246,18 @@
 						{#if attributes?.type === 'reasoning'}
 							{#if attributes?.done === 'true' && attributes?.duration}
 								{#if attributes.duration < 1}
-									{$i18n.t('Thought for less than a second')}
+									{$i18n.t('Reasoned for less than a second')}
 								{:else if attributes.duration < 60}
-									{$i18n.t('Thought for {{DURATION}} seconds', {
+									{$i18n.t('Reasoned for {{DURATION}} seconds', {
 										DURATION: attributes.duration
 									})}
 								{:else}
-									{$i18n.t('Thought for {{DURATION}}', {
+									{$i18n.t('Reasoned for {{DURATION}}', {
 										DURATION: dayjs.duration(attributes.duration, 'seconds').humanize()
 									})}
 								{/if}
 							{:else}
-								{$i18n.t('Thinking...')}
+								{$i18n.t('Reasoning...')}
 							{/if}
 						{:else if attributes?.type === 'code_interpreter'}
 							{#if attributes?.done === 'true'}