From a372c14fc50b0bbaf1fea2f5d3c729adf74e6d59 Mon Sep 17 00:00:00 2001
From: Chen Chia Yang <unayung@gmail.com>
Date: Wed, 8 Apr 2026 20:26:05 +0800
Subject: [PATCH] fix: strip <thought> tags from Gemma 4 responses in
 _strip_think_blocks

Gemma 4 (26B/31B) uses <thought>...</thought> to wrap its reasoning
output. This tag was not included in the existing list of reasoning tag
variants stripped by _strip_think_blocks(), causing raw thinking blocks
to leak into the visible response.

Added a new re.sub() line for <thought> and extended the cleanup regex
to include 'thought' alongside the existing variants.

Fixes #6148
---
 run_agent.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/run_agent.py b/run_agent.py
index 333dda392..2fd73160d 100644
--- a/run_agent.py
+++ b/run_agent.py
@@ -1872,12 +1872,13 @@ class AIAgent:
         if not content:
             return ""
         # Strip all reasoning tag variants: <think>, <thinking>, <THINKING>,
-        # <reasoning>, <REASONING_SCRATCHPAD>
+        # <reasoning>, <REASONING_SCRATCHPAD>, <thought> (Gemma 4)
         content = re.sub(r'<think>.*?</think>', '', content, flags=re.DOTALL)
         content = re.sub(r'<thinking>.*?</thinking>', '', content, flags=re.DOTALL | re.IGNORECASE)
         content = re.sub(r'<reasoning>.*?</reasoning>', '', content, flags=re.DOTALL)
         content = re.sub(r'<REASONING_SCRATCHPAD>.*?</REASONING_SCRATCHPAD>', '', content, flags=re.DOTALL)
-        content = re.sub(r'</?(?:think|thinking|reasoning|REASONING_SCRATCHPAD)>\s*', '', content, flags=re.IGNORECASE)
+        content = re.sub(r'<thought>.*?</thought>', '', content, flags=re.DOTALL | re.IGNORECASE)
+        content = re.sub(r'</?(?:think|thinking|reasoning|thought|REASONING_SCRATCHPAD)>\s*', '', content, flags=re.IGNORECASE)
         return content
 
     def _looks_like_codex_intermediate_ack(