diff --git a/app/client/platforms/deepseek.ts b/app/client/platforms/deepseek.ts
index 244601525..16dd39f1a 100644
--- a/app/client/platforms/deepseek.ts
+++ b/app/client/platforms/deepseek.ts
@@ -22,7 +22,10 @@ import {
   SpeechOptions,
 } from "../api";
 import { getClientConfig } from "@/app/config/client";
-import { getMessageTextContent } from "@/app/utils";
+import {
+  getMessageTextContent,
+  getMessageTextContentWithoutThinking,
+} from "@/app/utils";
 import { RequestPayload } from "./openai";
 import { fetch } from "@/app/utils/stream";
 
@@ -67,8 +70,13 @@ export class DeepSeekApi implements LLMApi {
   async chat(options: ChatOptions) {
     const messages: ChatOptions["messages"] = [];
     for (const v of options.messages) {
-      const content = getMessageTextContent(v);
-      messages.push({ role: v.role, content });
+      if (v.role === "assistant") {
+        const content = getMessageTextContentWithoutThinking(v);
+        messages.push({ role: v.role, content });
+      } else {
+        const content = getMessageTextContent(v);
+        messages.push({ role: v.role, content });
+      }
     }
 
     const modelConfig = {
diff --git a/app/utils.ts b/app/utils.ts
index 4f5b7b0b7..887efd574 100644
--- a/app/utils.ts
+++ b/app/utils.ts
@@ -16,8 +16,8 @@ export function trimTopic(topic: string) {
   return (
     topic
       // fix for gemini
-      .replace(/^["“”*]+|["“”*]+$/g, "")
-      .replace(/[，。！？”“"、,.!?*]*$/, "")
+      .replace(/^["""*]+|[""*]+$/g, "")
+      .replace(/[，。！？""""、,.!?*]*$/, "")
   );
 }
 
@@ -241,6 +241,28 @@ export function getMessageTextContent(message: RequestMessage) {
   return "";
 }
 
+export function getMessageTextContentWithoutThinking(message: RequestMessage) {
+  let content = "";
+
+  if (typeof message.content === "string") {
+    content = message.content;
+  } else {
+    for (const c of message.content) {
+      if (c.type === "text") {
+        content = c.text ?? "";
+        break;
+      }
+    }
+  }
+
+  // Filter out thinking lines (starting with "> ")
+  return content
+    .split("\n")
+    .filter((line) => !line.startsWith("> ") && line.trim() !== "")
+    .join("\n")
+    .trim();
+}
+
 export function getMessageImages(message: RequestMessage): string[] {
   if (typeof message.content === "string") {
     return [];
@@ -256,9 +278,7 @@ export function getMessageImages(message: RequestMessage): string[] {
 
 export function isVisionModel(model: string) {
   const visionModels = useAccessStore.getState().visionModels;
-  const envVisionModels = visionModels
-    ?.split(",")
-    .map((m) => m.trim());
+  const envVisionModels = visionModels?.split(",").map((m) => m.trim());
   if (envVisionModels?.includes(model)) {
     return true;
   }