diff --git a/service/package.json b/service/package.json
index 9dc486ad..0e83f8ea 100644
--- a/service/package.json
+++ b/service/package.json
@@ -42,7 +42,7 @@
     "mongodb": "^7.0.0",
     "multer": "^2.0.2",
     "nodemailer": "7.0.7",
-    "openai": "^6.9.1",
+    "openai": "^6.25.0",
     "request-ip": "^3.3.0",
     "speakeasy": "^2.0.0",
     "tsx": "^4.21.0",
diff --git a/service/pnpm-lock.yaml b/service/pnpm-lock.yaml
index aaf3c2ed..44e6fde1 100644
--- a/service/pnpm-lock.yaml
+++ b/service/pnpm-lock.yaml
@@ -48,8 +48,8 @@ importers:
         specifier: 7.0.7
         version: 7.0.7
       openai:
-        specifier: ^6.9.1
-        version: 6.9.1
+        specifier: ^6.25.0
+        version: 6.25.0
       request-ip:
         specifier: ^3.3.0
         version: 3.3.0
@@ -2448,8 +2448,8 @@ packages:
   once@1.4.0:
     resolution: {integrity: sha512-lNaJgI+2Q5URQBkccEKHTQOPaXdUxnZZElQTZY0MFUAuaEqe1E+Nyvgdz/aIyNi6Z9MzO5dv1H8n58/GELp3+w==}
 
-  openai@6.9.1:
-    resolution: {integrity: sha512-vQ5Rlt0ZgB3/BNmTa7bIijYFhz3YBceAA3Z4JuoMSBftBF9YqFHIEhZakSs+O/Ad7EaoEimZvHxD5ylRjN11Lg==}
+  openai@6.25.0:
+    resolution: {integrity: sha512-mEh6VZ2ds2AGGokWARo18aPISI1OhlgdEIC1ewhkZr8pSIT31dec0ecr9Nhxx0JlybyOgoAT1sWeKtwPZzJyww==}
     hasBin: true
     peerDependencies:
       ws: ^8.18.0
@@ -6320,7 +6320,7 @@ snapshots:
     dependencies:
       wrappy: 1.0.2
 
-  openai@6.9.1: {}
+  openai@6.25.0: {}
 
   optionator@0.9.3:
     dependencies:
diff --git a/service/src/chatgpt/index.ts b/service/src/chatgpt/index.ts
index 651bad77..11ba9368 100644
--- a/service/src/chatgpt/index.ts
+++ b/service/src/chatgpt/index.ts
@@ -538,6 +538,13 @@ search result: <search_result>${searchResultContent}</search_result>`,
       // @ts-expect-error For deepseek-reasoner model only. The reasoning contents of the assistant message, before the final answer.
       const reasoningContent = chunk.choices[0]?.delta?.reasoning_content || ''
       responseReasoning += reasoningContent
+
+      // https://github.com/vllm-project/vllm/pull/33402 Remove deprecated reasoning_content message field
+      // https://github.com/vllm-project/vllm/issues/27755 [RFC]：reasoning_content->reasoning #27755
+      // @ts-expect-error compilable vllm
+      const reasoning = chunk.choices[0]?.delta?.reasoning || ''
+      responseReasoning += reasoning
+
       const content = chunk.choices[0]?.delta?.content || ''
       responseText += content
       responseId = chunk.id
@@ -553,7 +560,7 @@ search result: <search_result>${searchResultContent}</search_result>`,
         finish_reason,
         // Incremental data
         delta: {
-          reasoning: reasoningContent, // reasoning content in this chunk
+          reasoning: reasoningContent || reasoning, // reasoning content in this chunk
           text: content, // text content in this chunk
         },
       }