From 65522c4d4b58fbbe7062e4a6075ccf8abd9ecc96 Mon Sep 17 00:00:00 2001
From: Your Name <jonathan.f.hill@gmail.com>
Date: Mon, 18 May 2026 12:24:10 -0500
Subject: [PATCH] fix: guard LLM response access in 39 cookbook examples
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

response.choices[0].message.content is Optional[str] — returns None when
the provider applies content filtering or the response consists entirely
of tool calls (finish_reason="tool_calls"). Accessing .content without a
guard raises AttributeError or propagates None silently.

Adds a uniform check before every unguarded .content access across all
cookbook utility files:

    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
        raise ValueError("LLM returned empty or filtered response")

Anthropic calls guarded analogously: len(response.content) == 0 or
response.content[0].text is None.
---
 cookbook/pocketflow-a2a/utils.py                         | 2 ++
 cookbook/pocketflow-agent-skills/utils.py                | 3 +++
 cookbook/pocketflow-agent/utils.py                       | 2 ++
 cookbook/pocketflow-agentic-rag/utils.py                 | 4 ++++
 cookbook/pocketflow-chat-guardrail/utils.py              | 6 ++++++
 cookbook/pocketflow-chat-memory/utils/call_llm.py        | 6 ++++++
 cookbook/pocketflow-chat/utils.py                        | 6 ++++++
 cookbook/pocketflow-cli-hitl/utils/call_llm.py           | 3 +++
 cookbook/pocketflow-code-generator/utils/call_llm.py     | 3 +++
 cookbook/pocketflow-coding-agent/utils/call_llm.py       | 4 ++++
 cookbook/pocketflow-debate/utils.py                      | 4 ++++
 cookbook/pocketflow-deep-research/utils.py               | 4 ++++
 cookbook/pocketflow-fastapi-background/utils/call_llm.py | 2 ++
 cookbook/pocketflow-gradio-hitl/utils/call_llm.py        | 3 +++
 cookbook/pocketflow-heartbeat/utils.py                   | 4 ++++
 cookbook/pocketflow-hello-world/utils/call_llm.py        | 2 ++
 cookbook/pocketflow-invoice/utils.py                     | 8 ++++++++
 cookbook/pocketflow-judge/utils.py                       | 4 ++++
 cookbook/pocketflow-lead-generation/utils.py             | 4 ++++
 cookbook/pocketflow-majority-vote/utils.py               | 3 +++
 cookbook/pocketflow-map-reduce/utils.py                  | 2 ++
 cookbook/pocketflow-mcp/utils.py                         | 6 ++++++
 cookbook/pocketflow-multi-agent/utils.py                 | 2 ++
 cookbook/pocketflow-newsletter/utils.py                  | 4 ++++
 cookbook/pocketflow-node/utils/call_llm.py               | 2 ++
 cookbook/pocketflow-notebook-lm/utils.py                 | 4 ++++
 cookbook/pocketflow-rag/utils.py                         | 2 ++
 cookbook/pocketflow-self-healing-mermaid/utils.py        | 4 ++++
 cookbook/pocketflow-structured-output/utils.py           | 2 ++
 cookbook/pocketflow-supervisor/utils.py                  | 2 ++
 cookbook/pocketflow-tao/utils.py                         | 2 ++
 cookbook/pocketflow-text2sql/utils/call_llm.py           | 2 ++
 cookbook/pocketflow-thinking/utils.py                    | 3 +++
 cookbook/pocketflow-tool-crawler/utils/call_llm.py       | 4 ++++
 cookbook/pocketflow-tool-embeddings/utils/call_llm.py    | 2 ++
 cookbook/pocketflow-tool-pdf-vision/tools/vision.py      | 6 ++++++
 cookbook/pocketflow-tool-search/utils/call_llm.py        | 4 ++++
 cookbook/pocketflow-voice-chat/utils/call_llm.py         | 6 ++++++
 cookbook/pocketflow-workflow/utils/call_llm.py           | 2 ++
 39 files changed, 138 insertions(+)

diff --git a/cookbook/pocketflow-a2a/utils.py b/cookbook/pocketflow-a2a/utils.py
index c56a1752..208a461c 100644
--- a/cookbook/pocketflow-a2a/utils.py
+++ b/cookbook/pocketflow-a2a/utils.py
@@ -8,6 +8,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 def search_web(query):
diff --git a/cookbook/pocketflow-agent-skills/utils.py b/cookbook/pocketflow-agent-skills/utils.py
index 037a3a8f..00e0987a 100644
--- a/cookbook/pocketflow-agent-skills/utils.py
+++ b/cookbook/pocketflow-agent-skills/utils.py
@@ -19,4 +19,7 @@ def call_llm(prompt: str) -> str:
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}],
     )
+    if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+        raise ValueError("LLM returned empty or filtered response")
     return response.choices[0].message.content
diff --git a/cookbook/pocketflow-agent/utils.py b/cookbook/pocketflow-agent/utils.py
index f8f52bd0..bf10ff8a 100644
--- a/cookbook/pocketflow-agent/utils.py
+++ b/cookbook/pocketflow-agent/utils.py
@@ -9,6 +9,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 def search_web_duckduckgo(query):
diff --git a/cookbook/pocketflow-agentic-rag/utils.py b/cookbook/pocketflow-agentic-rag/utils.py
index 88f5ed78..4393c60e 100644
--- a/cookbook/pocketflow-agentic-rag/utils.py
+++ b/cookbook/pocketflow-agentic-rag/utils.py
@@ -9,6 +9,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-chat-guardrail/utils.py b/cookbook/pocketflow-chat-guardrail/utils.py
index 7009d662..00850abe 100644
--- a/cookbook/pocketflow-chat-guardrail/utils.py
+++ b/cookbook/pocketflow-chat-guardrail/utils.py
@@ -10,6 +10,12 @@ def call_llm(messages):
         temperature=0.7
     )
     
+    if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+    
+        raise ValueError("LLM returned empty or filtered response")
+
+    
     return response.choices[0].message.content
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-chat-memory/utils/call_llm.py b/cookbook/pocketflow-chat-memory/utils/call_llm.py
index dc71d262..497e3ff1 100644
--- a/cookbook/pocketflow-chat-memory/utils/call_llm.py
+++ b/cookbook/pocketflow-chat-memory/utils/call_llm.py
@@ -10,6 +10,12 @@ def call_llm(messages):
         temperature=0.7
     )
     
+    if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+    
+        raise ValueError("LLM returned empty or filtered response")
+
+    
     return response.choices[0].message.content
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-chat/utils.py b/cookbook/pocketflow-chat/utils.py
index ffced048..618b19fc 100644
--- a/cookbook/pocketflow-chat/utils.py
+++ b/cookbook/pocketflow-chat/utils.py
@@ -10,6 +10,12 @@ def call_llm(messages):
         temperature=0.7
     )
     
+    if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+    
+        raise ValueError("LLM returned empty or filtered response")
+
+    
     return response.choices[0].message.content
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-cli-hitl/utils/call_llm.py b/cookbook/pocketflow-cli-hitl/utils/call_llm.py
index 5e3477ce..08171cff 100644
--- a/cookbook/pocketflow-cli-hitl/utils/call_llm.py
+++ b/cookbook/pocketflow-cli-hitl/utils/call_llm.py
@@ -10,6 +10,9 @@ def call_llm(prompt: str) -> str:
             {"role": "user", "content": prompt}
         ]
     )
+    if not response.content or response.content[0].text is None:
+
+        raise ValueError("LLM returned empty or filtered response")
     return response.content[0].text
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-code-generator/utils/call_llm.py b/cookbook/pocketflow-code-generator/utils/call_llm.py
index df57be20..f3898d86 100644
--- a/cookbook/pocketflow-code-generator/utils/call_llm.py
+++ b/cookbook/pocketflow-code-generator/utils/call_llm.py
@@ -10,6 +10,9 @@ def call_llm(prompt):
             {"role": "user", "content": prompt}
         ]
     )
+    if not response.content or response.content[0].text is None:
+
+        raise ValueError("LLM returned empty or filtered response")
     return response.content[0].text
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-coding-agent/utils/call_llm.py b/cookbook/pocketflow-coding-agent/utils/call_llm.py
index 4cefeb84..4bc96168 100644
--- a/cookbook/pocketflow-coding-agent/utils/call_llm.py
+++ b/cookbook/pocketflow-coding-agent/utils/call_llm.py
@@ -9,6 +9,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-debate/utils.py b/cookbook/pocketflow-debate/utils.py
index 2454bbcc..300e878a 100644
--- a/cookbook/pocketflow-debate/utils.py
+++ b/cookbook/pocketflow-debate/utils.py
@@ -9,6 +9,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-deep-research/utils.py b/cookbook/pocketflow-deep-research/utils.py
index ff43e5a7..8a5350a2 100644
--- a/cookbook/pocketflow-deep-research/utils.py
+++ b/cookbook/pocketflow-deep-research/utils.py
@@ -10,6 +10,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-fastapi-background/utils/call_llm.py b/cookbook/pocketflow-fastapi-background/utils/call_llm.py
index 37bf59f5..ae7c9070 100644
--- a/cookbook/pocketflow-fastapi-background/utils/call_llm.py
+++ b/cookbook/pocketflow-fastapi-background/utils/call_llm.py
@@ -7,6 +7,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-gradio-hitl/utils/call_llm.py b/cookbook/pocketflow-gradio-hitl/utils/call_llm.py
index 56996b95..8972ac18 100644
--- a/cookbook/pocketflow-gradio-hitl/utils/call_llm.py
+++ b/cookbook/pocketflow-gradio-hitl/utils/call_llm.py
@@ -14,6 +14,9 @@ def call_llm(message: str):
     response: ChatCompletion = client.chat.completions.create(
         model=model, messages=[{"role": "user", "content": message}]
     )
+    if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+        raise ValueError("LLM returned empty or filtered response")
     return response.choices[0].message.content
 
 
diff --git a/cookbook/pocketflow-heartbeat/utils.py b/cookbook/pocketflow-heartbeat/utils.py
index 65385754..0fb0a4fb 100644
--- a/cookbook/pocketflow-heartbeat/utils.py
+++ b/cookbook/pocketflow-heartbeat/utils.py
@@ -9,6 +9,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-hello-world/utils/call_llm.py b/cookbook/pocketflow-hello-world/utils/call_llm.py
index e6f7b588..7f4087b3 100644
--- a/cookbook/pocketflow-hello-world/utils/call_llm.py
+++ b/cookbook/pocketflow-hello-world/utils/call_llm.py
@@ -6,6 +6,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
     
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-invoice/utils.py b/cookbook/pocketflow-invoice/utils.py
index a24484a1..3fb08a5d 100644
--- a/cookbook/pocketflow-invoice/utils.py
+++ b/cookbook/pocketflow-invoice/utils.py
@@ -10,6 +10,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
@@ -31,6 +35,10 @@ def call_llm_with_image(prompt, image_base64):
                 {"type": "image_url", "image_url": {"url": f"data:image/png;base64,{image_base64}"}}
             ]}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-judge/utils.py b/cookbook/pocketflow-judge/utils.py
index 2454bbcc..300e878a 100644
--- a/cookbook/pocketflow-judge/utils.py
+++ b/cookbook/pocketflow-judge/utils.py
@@ -9,6 +9,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-lead-generation/utils.py b/cookbook/pocketflow-lead-generation/utils.py
index 0763f7e4..267b9598 100644
--- a/cookbook/pocketflow-lead-generation/utils.py
+++ b/cookbook/pocketflow-lead-generation/utils.py
@@ -9,6 +9,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-majority-vote/utils.py b/cookbook/pocketflow-majority-vote/utils.py
index afa1817f..6de50318 100644
--- a/cookbook/pocketflow-majority-vote/utils.py
+++ b/cookbook/pocketflow-majority-vote/utils.py
@@ -10,6 +10,9 @@ def call_llm(prompt):
             {"role": "user", "content": prompt}
         ]
     )
+    if not response.content or response.content[0].text is None:
+
+        raise ValueError("LLM returned empty or filtered response")
     return response.content[0].text
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-map-reduce/utils.py b/cookbook/pocketflow-map-reduce/utils.py
index 3427cbb6..bba0bc6b 100644
--- a/cookbook/pocketflow-map-reduce/utils.py
+++ b/cookbook/pocketflow-map-reduce/utils.py
@@ -7,6 +7,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 # Example usage
diff --git a/cookbook/pocketflow-mcp/utils.py b/cookbook/pocketflow-mcp/utils.py
index 3ee9f97f..40d56af9 100644
--- a/cookbook/pocketflow-mcp/utils.py
+++ b/cookbook/pocketflow-mcp/utils.py
@@ -13,6 +13,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 def get_tools(server_script_path=None):
@@ -126,6 +128,10 @@ async def _call_tool():
             async with ClientSession(read, write) as session:
                 await session.initialize()
                 result = await session.call_tool(tool_name, arguments)
+                if not result.content or result.content[0].text is None:
+
+                    raise ValueError("LLM returned empty or filtered response")
+
                 return result.content[0].text
     
     return asyncio.run(_call_tool())
diff --git a/cookbook/pocketflow-multi-agent/utils.py b/cookbook/pocketflow-multi-agent/utils.py
index 5104b84d..09c25373 100644
--- a/cookbook/pocketflow-multi-agent/utils.py
+++ b/cookbook/pocketflow-multi-agent/utils.py
@@ -7,6 +7,8 @@ def call_llm(prompt):
         model="gpt-4o-mini",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 # Example usage
diff --git a/cookbook/pocketflow-newsletter/utils.py b/cookbook/pocketflow-newsletter/utils.py
index ce3c0d55..13eea4aa 100644
--- a/cookbook/pocketflow-newsletter/utils.py
+++ b/cookbook/pocketflow-newsletter/utils.py
@@ -10,6 +10,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-node/utils/call_llm.py b/cookbook/pocketflow-node/utils/call_llm.py
index e6f7b588..7f4087b3 100644
--- a/cookbook/pocketflow-node/utils/call_llm.py
+++ b/cookbook/pocketflow-node/utils/call_llm.py
@@ -6,6 +6,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
     
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-notebook-lm/utils.py b/cookbook/pocketflow-notebook-lm/utils.py
index 4638ad9f..e34985c9 100644
--- a/cookbook/pocketflow-notebook-lm/utils.py
+++ b/cookbook/pocketflow-notebook-lm/utils.py
@@ -9,6 +9,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-rag/utils.py b/cookbook/pocketflow-rag/utils.py
index 0aae230b..41d557d4 100644
--- a/cookbook/pocketflow-rag/utils.py
+++ b/cookbook/pocketflow-rag/utils.py
@@ -8,6 +8,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 def get_embedding(text):
diff --git a/cookbook/pocketflow-self-healing-mermaid/utils.py b/cookbook/pocketflow-self-healing-mermaid/utils.py
index 2454bbcc..300e878a 100644
--- a/cookbook/pocketflow-self-healing-mermaid/utils.py
+++ b/cookbook/pocketflow-self-healing-mermaid/utils.py
@@ -9,6 +9,10 @@ def call_llm(prompt):
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return r.choices[0].message.content
     elif os.environ.get("GEMINI_API_KEY"):
         from google import genai
diff --git a/cookbook/pocketflow-structured-output/utils.py b/cookbook/pocketflow-structured-output/utils.py
index 3427cbb6..bba0bc6b 100644
--- a/cookbook/pocketflow-structured-output/utils.py
+++ b/cookbook/pocketflow-structured-output/utils.py
@@ -7,6 +7,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 # Example usage
diff --git a/cookbook/pocketflow-supervisor/utils.py b/cookbook/pocketflow-supervisor/utils.py
index c56a1752..208a461c 100644
--- a/cookbook/pocketflow-supervisor/utils.py
+++ b/cookbook/pocketflow-supervisor/utils.py
@@ -8,6 +8,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 def search_web(query):
diff --git a/cookbook/pocketflow-tao/utils.py b/cookbook/pocketflow-tao/utils.py
index 1402664a..d5760b4b 100644
--- a/cookbook/pocketflow-tao/utils.py
+++ b/cookbook/pocketflow-tao/utils.py
@@ -9,6 +9,8 @@ def call_llm(prompt):
         model=os.environ.get("OPENAI_MODEL", "openai/gpt-4.1-nano"),
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-text2sql/utils/call_llm.py b/cookbook/pocketflow-text2sql/utils/call_llm.py
index 3427cbb6..bba0bc6b 100644
--- a/cookbook/pocketflow-text2sql/utils/call_llm.py
+++ b/cookbook/pocketflow-text2sql/utils/call_llm.py
@@ -7,6 +7,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 # Example usage
diff --git a/cookbook/pocketflow-thinking/utils.py b/cookbook/pocketflow-thinking/utils.py
index 468798c8..404d5fe1 100644
--- a/cookbook/pocketflow-thinking/utils.py
+++ b/cookbook/pocketflow-thinking/utils.py
@@ -10,6 +10,9 @@ def call_llm(prompt):
             {"role": "user", "content": prompt}
         ]
     )
+    if not response.content or response.content[0].text is None:
+
+        raise ValueError("LLM returned empty or filtered response")
     return response.content[0].text
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-tool-crawler/utils/call_llm.py b/cookbook/pocketflow-tool-crawler/utils/call_llm.py
index 8c72c82e..526d9787 100644
--- a/cookbook/pocketflow-tool-crawler/utils/call_llm.py
+++ b/cookbook/pocketflow-tool-crawler/utils/call_llm.py
@@ -18,6 +18,10 @@ def call_llm(prompt: str) -> str:
             model="gpt-4",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return response.choices[0].message.content
         
     except Exception as e:
diff --git a/cookbook/pocketflow-tool-embeddings/utils/call_llm.py b/cookbook/pocketflow-tool-embeddings/utils/call_llm.py
index fe5d04c1..03b5a929 100644
--- a/cookbook/pocketflow-tool-embeddings/utils/call_llm.py
+++ b/cookbook/pocketflow-tool-embeddings/utils/call_llm.py
@@ -9,6 +9,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
     
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-tool-pdf-vision/tools/vision.py b/cookbook/pocketflow-tool-pdf-vision/tools/vision.py
index c5042bba..68ba9dee 100644
--- a/cookbook/pocketflow-tool-pdf-vision/tools/vision.py
+++ b/cookbook/pocketflow-tool-pdf-vision/tools/vision.py
@@ -31,6 +31,12 @@ def extract_text_from_image(image: Image.Image, prompt: str = None) -> str:
         }]
     )
     
+    if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+    
+        raise ValueError("LLM returned empty or filtered response")
+
+    
     return response.choices[0].message.content
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-tool-search/utils/call_llm.py b/cookbook/pocketflow-tool-search/utils/call_llm.py
index ddacef6c..9af0c07d 100644
--- a/cookbook/pocketflow-tool-search/utils/call_llm.py
+++ b/cookbook/pocketflow-tool-search/utils/call_llm.py
@@ -22,6 +22,10 @@ def call_llm(prompt: str) -> str:
             model="gpt-4o",
             messages=[{"role": "user", "content": prompt}]
         )
+        if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+            raise ValueError("LLM returned empty or filtered response")
+
         return response.choices[0].message.content
         
     except Exception as e:
diff --git a/cookbook/pocketflow-voice-chat/utils/call_llm.py b/cookbook/pocketflow-voice-chat/utils/call_llm.py
index 1b70b63b..c1e6c708 100644
--- a/cookbook/pocketflow-voice-chat/utils/call_llm.py
+++ b/cookbook/pocketflow-voice-chat/utils/call_llm.py
@@ -10,6 +10,12 @@ def call_llm(messages):
         temperature=0.7
     )
     
+    if not response.choices or response.choices[0].message is None or response.choices[0].message.content is None:
+
+    
+        raise ValueError("LLM returned empty or filtered response")
+
+    
     return response.choices[0].message.content
 
 if __name__ == "__main__":
diff --git a/cookbook/pocketflow-workflow/utils/call_llm.py b/cookbook/pocketflow-workflow/utils/call_llm.py
index 3427cbb6..bba0bc6b 100644
--- a/cookbook/pocketflow-workflow/utils/call_llm.py
+++ b/cookbook/pocketflow-workflow/utils/call_llm.py
@@ -7,6 +7,8 @@ def call_llm(prompt):
         model="gpt-4o",
         messages=[{"role": "user", "content": prompt}]
     )
+    if not r.choices or r.choices[0].message is None or r.choices[0].message.content is None:
+        raise ValueError("LLM returned empty or filtered response")
     return r.choices[0].message.content
 
 # Example usage