diff --git a/frontend/src/features/tasks/components/ChatInput.tsx b/frontend/src/features/tasks/components/ChatInput.tsx
index b7bc4819..bbfbc1c3 100644
--- a/frontend/src/features/tasks/components/ChatInput.tsx
+++ b/frontend/src/features/tasks/components/ChatInput.tsx
@@ -4,7 +4,7 @@
 
 'use client';
 
-import React, { useState } from 'react';
+import React, { useState, useRef, useEffect } from 'react';
 import TextareaAutosize from 'react-textarea-autosize';
 import { useTranslation } from '@/hooks/useTranslation';
 import { useIsMobile } from '@/features/layout/hooks/useMediaQuery';
@@ -29,6 +29,7 @@ export default function ChatInput({
   const placeholderKey = taskType === 'chat' ? 'chat.placeholder_chat' : 'chat.placeholder_code';
   const [isComposing, setIsComposing] = useState(false);
   const isMobile = useIsMobile();
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
 
   const handleCompositionStart = () => {
     setIsComposing(true);
@@ -51,14 +52,164 @@ export default function ChatInput({
     }
   };
 
+  const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    // Handle Tab key - insert \t placeholder instead of default tab behavior
+    if (e.key === 'Tab' && !disabled && !isComposing) {
+      e.preventDefault();
+
+      const textarea = e.target as HTMLTextAreaElement;
+      const start = textarea.selectionStart;
+      const end = textarea.selectionEnd;
+      const value = textarea.value;
+
+      // Insert \t placeholder at cursor position
+      const newValue = value.substring(0, start) + '\t' + value.substring(end);
+
+      setMessage(newValue);
+
+      // Set cursor position after the inserted tab
+      setTimeout(() => {
+        textarea.selectionStart = start + 1;
+        textarea.selectionEnd = start + 1;
+      }, 0);
+      return;
+    }
+
+    // Handle Backspace key - remove auto-indented whitespace
+    if (e.key === 'Backspace' && !disabled && !isComposing) {
+      const textarea = e.target as HTMLTextAreaElement;
+      const start = textarea.selectionStart;
+      const end = textarea.selectionEnd;
+      const value = textarea.value;
+
+      // Only handle when cursor is at a single position (no selection)
+      if (start === end && start > 0) {
+        // Get the current line and previous character
+        const lines = value.substring(0, start).split('\n');
+        const currentLine = lines[lines.length - 1];
+
+        // Check if we're at the beginning of a line and the line contains only whitespace
+        if (currentLine.trim() === '' && currentLine.length > 0) {
+          e.preventDefault();
+
+          // Remove the entire line of whitespace and the newline character
+          const previousLines = lines.slice(0, -1);
+          const remainingText = value.substring(start);
+          const newValue = previousLines.join('\n') + (previousLines.length > 0 ? '\n' : '') + remainingText;
+
+          setMessage(newValue);
+
+          // Set cursor position at the end of the previous line
+          const newCursorPos = previousLines.length > 0 ? previousLines.join('\n').length + 1 : 0;
+          setTimeout(() => {
+            textarea.selectionStart = newCursorPos;
+            textarea.selectionEnd = newCursorPos;
+          }, 0);
+          return;
+        }
+
+        // Check if we're deleting whitespace that was auto-indented
+        const charBeforeCursor = value.substring(start - 1, start);
+        if (charBeforeCursor === ' ' || charBeforeCursor === '\t') {
+          // Get the line start position
+          const lineStart = value.lastIndexOf('\n', start - 1) + 1;
+          const lineContent = value.substring(lineStart, start);
+
+          // If the line contains only whitespace up to cursor, remove all whitespace
+          if (lineContent.trim() === '') {
+            e.preventDefault();
+            const newValue = value.substring(0, lineStart) + value.substring(start);
+            setMessage(newValue);
+
+            setTimeout(() => {
+              textarea.selectionStart = lineStart;
+              textarea.selectionEnd = lineStart;
+            }, 0);
+            return;
+          }
+        }
+      }
+    }
+
+    // Handle Enter key for auto-indentation
+    if (e.key === 'Enter' && !disabled && !isComposing) {
+      // Desktop: Enter sends message, Shift+Enter creates new line
+      if (!isMobile && !e.shiftKey) {
+        e.preventDefault();
+        handleSendMessage();
+        return;
+      }
+
+      // Mobile: Enter creates new line with auto-indentation
+      // Desktop: Shift+Enter creates new line with auto-indentation
+      if (isMobile || e.shiftKey) {
+        e.preventDefault();
+
+        const textarea = e.target as HTMLTextAreaElement;
+        const start = textarea.selectionStart;
+        const end = textarea.selectionEnd;
+        const value = textarea.value;
+
+        // Get the current line and its leading whitespace
+        const lines = value.substring(0, start).split('\n');
+        const currentLine = lines[lines.length - 1];
+        const leadingWhitespace = currentLine.match(/^\s*/)?.[0] || '';
+
+        // Insert new line with preserved indentation
+        const newValue = value.substring(0, start) + '\n' + leadingWhitespace + value.substring(end);
+
+        setMessage(newValue);
+
+        // Set cursor position after the inserted whitespace
+        setTimeout(() => {
+          textarea.selectionStart = start + 1 + leadingWhitespace.length;
+          textarea.selectionEnd = start + 1 + leadingWhitespace.length;
+        }, 0);
+        return;
+      }
+    }
+  };
+
+  const handleInsertTab = () => {
+    if (disabled || isComposing) return;
+
+    const textarea = textareaRef.current;
+    if (!textarea) return;
+
+    const start = textarea.selectionStart;
+    const end = textarea.selectionEnd;
+    const value = textarea.value;
+
+    // Insert \t placeholder at cursor position
+    const newValue = value.substring(0, start) + '\t' + value.substring(end);
+
+    setMessage(newValue);
+
+    // Set cursor position after inserted tab
+    setTimeout(() => {
+      textarea.selectionStart = start + 1;
+      textarea.selectionEnd = start + 1;
+      textarea.focus();
+    }, 0);
+  };
+
+  // Auto-focus on mount
+  useEffect(() => {
+    if (textareaRef.current && !disabled) {
+      textareaRef.current.focus();
+    }
+  }, [disabled]);
+
   return (
     <div className="w-full">
       <TextareaAutosize
+        ref={textareaRef}
         value={message}
         onChange={e => {
           if (!disabled) setMessage(e.target.value);
         }}
-        onKeyDown={handleKeyPress}
+        onKeyDown={handleKeyDown}
+        onKeyPress={handleKeyPress}
         onCompositionStart={handleCompositionStart}
         onCompositionEnd={handleCompositionEnd}
         placeholder={t(placeholderKey)}
@@ -66,8 +217,20 @@ export default function ChatInput({
         disabled={disabled}
         minRows={isMobile ? 2 : 3}
         maxRows={isMobile ? 6 : 8}
-        style={{ resize: 'none', overflow: 'auto' }}
+        style={{ resize: 'none', overflow: 'auto', whiteSpace: 'pre-wrap', wordWrap: 'break-word' }}
       />
+      {/* Mobile toolbar with Tab button */}
+      {isMobile && (
+        <div className="flex justify-end mt-2 px-1">
+          <button
+            onClick={handleInsertTab}
+            disabled={disabled}
+            className="px-3 py-1 text-sm bg-gray-100 hover:bg-gray-200 dark:bg-gray-700 dark:hover:bg-gray-600 rounded-md transition-colors disabled:opacity-50 disabled:cursor-not-allowed text-text-primary"
+          >
+            Tab
+          </button>
+        </div>
+      )}
     </div>
   );
 }