diff --git a/apps/client/src/services/llm_chat.ts b/apps/client/src/services/llm_chat.ts
index b2e4efc947..254ff069e1 100644
--- a/apps/client/src/services/llm_chat.ts
+++ b/apps/client/src/services/llm_chat.ts
@@ -22,6 +22,7 @@ export interface Citation {
 
 export interface StreamCallbacks {
     onChunk: (text: string) => void;
+    onThinking?: (text: string) => void;
     onToolUse?: (toolName: string, input: Record<string, unknown>) => void;
     onToolResult?: (toolName: string, result: string) => void;
     onCitation?: (citation: Citation) => void;
@@ -80,6 +81,9 @@ export async function streamChatCompletion(
                             case "text":
                                 callbacks.onChunk(data.content);
                                 break;
+                            case "thinking":
+                                callbacks.onThinking?.(data.content);
+                                break;
                             case "tool_use":
                                 callbacks.onToolUse?.(data.toolName, data.toolInput);
                                 break;
diff --git a/apps/client/src/translations/en/translation.json b/apps/client/src/translations/en/translation.json
index 75be7d3828..5f03de87ab 100644
--- a/apps/client/src/translations/en/translation.json
+++ b/apps/client/src/translations/en/translation.json
@@ -1619,7 +1619,9 @@
     "searching_web": "Searching the web...",
     "web_search": "Web search",
     "sources": "Sources",
-    "extended_thinking": "Extended thinking"
+    "extended_thinking": "Extended thinking",
+    "thinking": "Thinking...",
+    "thought_process": "Thought process"
   },
   "shared_switch": {
     "shared": "Shared",
diff --git a/apps/client/src/widgets/type_widgets/llm_chat/ChatMessage.tsx b/apps/client/src/widgets/type_widgets/llm_chat/ChatMessage.tsx
index b583c4a3b3..ea986532bb 100644
--- a/apps/client/src/widgets/type_widgets/llm_chat/ChatMessage.tsx
+++ b/apps/client/src/widgets/type_widgets/llm_chat/ChatMessage.tsx
@@ -10,7 +10,7 @@ marked.setOptions({
     gfm: true // GitHub Flavored Markdown
 });
 
-type MessageType = "message" | "error";
+type MessageType = "message" | "error" | "thinking";
 
 interface StoredMessage {
     id: string;
@@ -30,21 +30,39 @@ interface Props {
 export default function ChatMessage({ message, isStreaming }: Props) {
     const roleLabel = message.role === "user" ? "You" : "Assistant";
     const isError = message.type === "error";
+    const isThinking = message.type === "thinking";
 
-    // Only render markdown for assistant messages (not errors)
+    // Render markdown for assistant messages (not errors or thinking)
     const renderedContent = useMemo(() => {
-        if (message.role === "assistant" && !isError) {
+        if (message.role === "assistant" && !isError && !isThinking) {
             return marked.parse(message.content) as string;
         }
         return null;
-    }, [message.content, message.role, isError]);
+    }, [message.content, message.role, isError, isThinking]);
 
     const messageClasses = [
         "llm-chat-message",
         `llm-chat-message-${message.role}`,
-        isError && "llm-chat-message-error"
+        isError && "llm-chat-message-error",
+        isThinking && "llm-chat-message-thinking"
     ].filter(Boolean).join(" ");
 
+    // Render thinking messages in a collapsible details element
+    if (isThinking) {
+        return (
+            <details className={messageClasses}>
+                <summary className="llm-chat-thinking-summary">
+                    <span className="bx bx-brain" />
+                    {t("llm_chat.thought_process")}
+                </summary>
+                <div className="llm-chat-message-content llm-chat-thinking-content">
+                    {message.content}
+                    {isStreaming && <span className="llm-chat-cursor" />}
+                </div>
+            </details>
+        );
+    }
+
     return (
         <div className={messageClasses}>
             <div className="llm-chat-message-role">
diff --git a/apps/client/src/widgets/type_widgets/llm_chat/LlmChat.css b/apps/client/src/widgets/type_widgets/llm_chat/LlmChat.css
index a4fcb771ea..51ff8f1382 100644
--- a/apps/client/src/widgets/type_widgets/llm_chat/LlmChat.css
+++ b/apps/client/src/widgets/type_widgets/llm_chat/LlmChat.css
@@ -164,6 +164,51 @@
     color: var(--danger-text-color, #c00);
 }
 
+/* Thinking message (collapsible) */
+.llm-chat-message-thinking {
+    background: var(--accented-background-color);
+    border: 1px dashed var(--main-border-color);
+    cursor: pointer;
+}
+
+.llm-chat-thinking-summary {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    font-size: 0.85rem;
+    font-weight: 500;
+    color: var(--muted-text-color);
+    padding: 0.25rem 0;
+    list-style: none;
+}
+
+.llm-chat-thinking-summary::-webkit-details-marker {
+    display: none;
+}
+
+.llm-chat-thinking-summary::before {
+    content: "▶";
+    font-size: 0.7em;
+    transition: transform 0.2s ease;
+}
+
+.llm-chat-message-thinking[open] .llm-chat-thinking-summary::before {
+    transform: rotate(90deg);
+}
+
+.llm-chat-thinking-summary .bx {
+    font-size: 1rem;
+}
+
+.llm-chat-thinking-content {
+    margin-top: 0.5rem;
+    padding-top: 0.5rem;
+    border-top: 1px solid var(--main-border-color);
+    font-size: 0.9rem;
+    color: var(--muted-text-color);
+    white-space: pre-wrap;
+}
+
 /* Input form */
 .llm-chat-input-form {
     display: flex;
diff --git a/apps/client/src/widgets/type_widgets/llm_chat/LlmChat.tsx b/apps/client/src/widgets/type_widgets/llm_chat/LlmChat.tsx
index 6285d66650..c098499891 100644
--- a/apps/client/src/widgets/type_widgets/llm_chat/LlmChat.tsx
+++ b/apps/client/src/widgets/type_widgets/llm_chat/LlmChat.tsx
@@ -6,7 +6,7 @@ import { TypeWidgetProps } from "../type_widget.js";
 import ChatMessage from "./ChatMessage.js";
 import "./LlmChat.css";
 
-type MessageType = "message" | "error";
+type MessageType = "message" | "error" | "thinking";
 
 interface StoredMessage {
     id: string;
@@ -30,6 +30,7 @@ export default function LlmChat({ note, ntxId, noteContext }: TypeWidgetProps) {
     const [input, setInput] = useState("");
     const [isStreaming, setIsStreaming] = useState(false);
     const [streamingContent, setStreamingContent] = useState("");
+    const [streamingThinking, setStreamingThinking] = useState("");
     const [toolActivity, setToolActivity] = useState<string | null>(null);
     const [pendingCitations, setPendingCitations] = useState<Citation[]>([]);
     const [enableWebSearch, setEnableWebSearch] = useState(true);
@@ -45,7 +46,7 @@ export default function LlmChat({ note, ntxId, noteContext }: TypeWidgetProps) {
 
     useEffect(() => {
         scrollToBottom();
-    }, [messages, streamingContent, toolActivity, scrollToBottom]);
+    }, [messages, streamingContent, streamingThinking, toolActivity, scrollToBottom]);
 
     // Use a ref to store the latest messages for getData
     const messagesRef = useRef(messages);
@@ -120,8 +121,10 @@ export default function LlmChat({ note, ntxId, noteContext }: TypeWidgetProps) {
         setInput("");
         setIsStreaming(true);
         setStreamingContent("");
+        setStreamingThinking("");
 
         let assistantContent = "";
+        let thinkingContent = "";
         const citations: Citation[] = [];
 
         const apiMessages: ChatMessageData[] = newMessages.map(m => ({
@@ -138,6 +141,11 @@ export default function LlmChat({ note, ntxId, noteContext }: TypeWidgetProps) {
                     setStreamingContent(assistantContent);
                     setToolActivity(null); // Clear tool activity when text starts
                 },
+                onThinking: (text) => {
+                    thinkingContent += text;
+                    setStreamingThinking(thinkingContent);
+                    setToolActivity(t("llm_chat.thinking"));
+                },
                 onToolUse: (toolName, _input) => {
                     const toolLabel = toolName === "web_search"
                         ? t("llm_chat.searching_web")
@@ -160,22 +168,41 @@ export default function LlmChat({ note, ntxId, noteContext }: TypeWidgetProps) {
                     };
                     setMessages(prev => [...prev, errorMessage]);
                     setStreamingContent("");
+                    setStreamingThinking("");
                     setIsStreaming(false);
                     setToolActivity(null);
                     setShouldSave(true);
                 },
                 onDone: () => {
+                    const newMessages: StoredMessage[] = [];
+
+                    // Save thinking as a separate message if present
+                    if (thinkingContent) {
+                        newMessages.push({
+                            id: crypto.randomUUID(),
+                            role: "assistant",
+                            content: thinkingContent,
+                            createdAt: new Date().toISOString(),
+                            type: "thinking"
+                        });
+                    }
+
                     if (assistantContent) {
-                        const assistantMessage: StoredMessage = {
+                        newMessages.push({
                             id: crypto.randomUUID(),
                             role: "assistant",
                             content: assistantContent,
                             createdAt: new Date().toISOString(),
                             citations: citations.length > 0 ? citations : undefined
-                        };
-                        setMessages(prev => [...prev, assistantMessage]);
+                        });
                     }
+
+                    if (newMessages.length > 0) {
+                        setMessages(prev => [...prev, ...newMessages]);
+                    }
+
                     setStreamingContent("");
+                    setStreamingThinking("");
                     setPendingCitations([]);
                     setIsStreaming(false);
                     setToolActivity(null);
@@ -214,12 +241,24 @@ export default function LlmChat({ note, ntxId, noteContext }: TypeWidgetProps) {
                 {messages.map(msg => (
                     <ChatMessage key={msg.id} message={msg} />
                 ))}
-                {toolActivity && (
+                {toolActivity && !streamingThinking && (
                     <div className="llm-chat-tool-activity">
                         <span className="llm-chat-tool-spinner" />
                         {toolActivity}
                     </div>
                 )}
+                {isStreaming && streamingThinking && (
+                    <ChatMessage
+                        message={{
+                            id: "streaming-thinking",
+                            role: "assistant",
+                            content: streamingThinking,
+                            createdAt: new Date().toISOString(),
+                            type: "thinking"
+                        }}
+                        isStreaming
+                    />
+                )}
                 {isStreaming && streamingContent && (
                     <ChatMessage
                         message={{
diff --git a/apps/server/src/services/llm/providers/anthropic.ts b/apps/server/src/services/llm/providers/anthropic.ts
index 545c7b1c9a..50973e37b6 100644
--- a/apps/server/src/services/llm/providers/anthropic.ts
+++ b/apps/server/src/services/llm/providers/anthropic.ts
@@ -59,6 +59,7 @@ export class AnthropicProvider implements LlmProvider {
                     type: "enabled",
                     budget_tokens: thinkingBudget
                 };
+                console.log(`[LLM] Extended thinking enabled with budget: ${thinkingBudget} tokens`);
             }
 
             const stream = this.client.messages.stream(streamParams);
@@ -73,11 +74,15 @@ export class AnthropicProvider implements LlmProvider {
                             toolName: block.name,
                             toolInput: {} // Input comes in deltas
                         };
+                    } else if (block.type === "thinking") {
+                        console.log("[LLM] Thinking block started");
                     }
                 } else if (event.type === "content_block_delta") {
                     const delta = event.delta;
                     if (delta.type === "text_delta") {
                         yield { type: "text", content: delta.text };
+                    } else if (delta.type === "thinking_delta") {
+                        yield { type: "thinking", content: (delta as any).thinking };
                     } else if (delta.type === "input_json_delta") {
                         // Tool input is being streamed - we could accumulate it
                         // For now, we already emitted tool_use at start
diff --git a/apps/server/src/services/llm/types.ts b/apps/server/src/services/llm/types.ts
index d30af7bf90..fdcfa91a83 100644
--- a/apps/server/src/services/llm/types.ts
+++ b/apps/server/src/services/llm/types.ts
@@ -13,6 +13,7 @@ export interface LlmMessage {
  */
 export type LlmStreamChunk =
     | { type: "text"; content: string }
+    | { type: "thinking"; content: string }
     | { type: "tool_use"; toolName: string; toolInput: Record<string, unknown> }
     | { type: "tool_result"; toolName: string; result: string }
     | { type: "citation"; url: string; title?: string }