Typewriter Mode

Typewriter mode makes AI-generated text appear to be typed naturally by simulating human typing patterns, including realistic delays, typos, and corrections. This mode is essential for coding interviews and platforms with paste detection.

Why Typewriter Mode?

Many coding interview platforms and proctored environments detect clipboard operations and automated pasting. Typewriter mode bypasses these restrictions by:

Typing each character individually with human-like timing
Introducing realistic typos and corrections
Varying keystroke delays based on context (punctuation, spaces, etc.)
Handling newlines and indentation like a real developer

While typewriter mode produces human-like typing patterns, you are responsible for following the rules and policies of any platform or interview you use it with. Tabby is a productivity tool, not a cheating tool.

Typing Modes

Tabby offers two typewriter implementations optimized for different scenarios:

Simple Typewriter

For basic text editors like Notepad, chat applications, and forms:

// frontend/electron/src/services/text-handler.ts:153
export async function typeSimpleToLastWindow(
  text: string,
  config: Partial<HumanTypingConfig> = {}
): Promise<void>

Best for:

Plain text editors
Email and messaging
Web forms
Documentation

LeetCode Typewriter

For code editors with auto-indent (LeetCode, CodeSignal, HackerRank, etc.):

// frontend/electron/src/services/text-handler.ts:219
export async function typeLeetCodeToLastWindow(
  text: string,
  config: Partial<HumanTypingConfig> = {}
): Promise<void>

Best for:

LeetCode interviews
Online coding platforms
IDEs with auto-formatting
Smart code editors

LeetCode mode includes special handling to reset auto-indentation and preserve exact spacing from your source code.

Human Typing Simulation

Realistic Typos

Typewriter mode uses a QWERTY keyboard proximity map to generate believable typos:

// frontend/electron/src/services/text-handler.ts:90
const QWERTY_NEIGHBORS: { [key: string]: string } = {
  'a': 'qwsz',  // Keys adjacent to 'a'
  'b': 'vghn',  // Keys adjacent to 'b'
  'e': 'wrsdf', // Keys adjacent to 'e'
  // ... full keyboard mapping
};

When a typo occurs:

Wrong Key Press

Types a neighboring character (e.g., ‘r’ instead of ‘t’)

Thinking Pause

Waits 100-400ms (human reaction time)

Correction

Presses Backspace to delete the typo

Retry

Types the correct character after 50-200ms

Variable Timing

Typewriter mode adds human-like variation to keystroke timing:

interface HumanTypingConfig {
  errorRate: number;           // 0.03 = 3% typo rate
  minDelay: number;            // 20ms minimum between keys
  maxDelay: number;            // 100ms maximum between keys
  punctuationPauseMin: number; // 150ms extra after punctuation
  punctuationPauseMax: number; // 400ms extra after punctuation
  spacePauseMin: number;       // 30ms extra after spaces
  spacePauseMax: number;       // 100ms extra after spaces
  correctionPauseMin: number;  // 100ms before fixing typo
  correctionPauseMax: number;  // 400ms before fixing typo
  postCorrectionPauseMin: number; // 50ms after backspace
  postCorrectionPauseMax: number; // 200ms after backspace
}

Default Configuration

const DEFAULT_HUMAN_CONFIG: HumanTypingConfig = {
  errorRate: 0.03,              // 3% of characters
  minDelay: 20,
  maxDelay: 100,
  punctuationPauseMin: 150,
  punctuationPauseMax: 400,
  spacePauseMin: 30,
  spacePauseMax: 100,
  correctionPauseMin: 100,
  correctionPauseMax: 400,
  postCorrectionPauseMin: 50,
  postCorrectionPauseMax: 200
};

LeetCode Mode: Auto-Indent Handling

The LeetCode typewriter includes sophisticated indentation control:

// For each new line:
if (i > 0) {
  // 1. Press Enter (triggers auto-indent)
  await keyboard.pressKey(Key.Enter);
  await keyboard.releaseKey(Key.Enter);
  
  // 2. Go to start of line
  await keyboard.pressKey(Key.Home);
  await keyboard.releaseKey(Key.Home);
  
  // 3. Select auto-indented content
  await keyboard.pressKey(Key.LeftShift, Key.End);
  await keyboard.releaseKey(Key.LeftShift, Key.End);
  
  // 4. Delete it
  await keyboard.pressKey(Key.Backspace);
  await keyboard.releaseKey(Key.Backspace);
  
  // 5. Type the CORRECT indentation
  // (including original leading spaces)
}

This ensures your code maintains exact indentation even in smart editors.

Timing Examples

Typing the word “hello” with typewriter mode:

Action                    Delay (ms)
──────────────────────────────────
h                         67
e                         43
l                         89
l → k (typo)             52
(pause)                   287
Backspace                 112
l                         81
o                         56

Total time: ~787ms vs. instant paste

Cancellation

Stop typewriter mode at any time: Keyboard: Press Shift+Escape Programmatic:

import { cancelTyping } from './services/text-handler';

cancelTyping(); // Immediately stops typing

The typing loop checks isTypingCancelled after each character:

for (const char of text) {
  await keyboard.type(char);
  await sleep(delay);
  
  if (isTypingCancelled) return; // Exit immediately
}

Usage in Tabby

Typewriter mode is automatically used based on your Text Output Mode setting:

Open Settings (Ctrl+, or system tray → Settings)
Navigate to Automation section
Select your preferred mode:
- Paste - Standard clipboard paste (fast)
- Typewriter - Character-by-character (basic editors)
- Typewriter (LeetCode) - Character-by-character with indent control

The selected mode applies globally to all text insertion operations including action menu results, AI suggestions, and interview copilot code.

Performance

Typing speed varies based on content:

Content Type	Avg. Speed	Example Time
Short text (50 chars)	60-80 WPM	~5 seconds
Code snippet (200 chars)	50-70 WPM	~25 seconds
Full solution (500 chars)	45-65 WPM	~60 seconds

Typewriter mode is significantly slower than paste mode. Only use it when paste detection is a concern.

Implementation Reference

Full source code: frontend/electron/src/services/text-handler.ts Key functions:

typeSimpleToLastWindow() - Lines 153-216
typeLeetCodeToLastWindow() - Lines 219-302
shouldMakeTypo() - Line 143
getRandomNeighborChar() - Line 133
randomInRange() - Line 129

Desktop Control - Window management and keyboard automation
Interview Copilot - Real-time coding interview assistance
Action Menu - Quick AI transformations

Interview Copilot

AI Assistance

Memory & Brain

Voice Features

Automation

Why Typewriter Mode?

Typing Modes

Simple Typewriter

LeetCode Typewriter

Human Typing Simulation

Realistic Typos

Variable Timing

Default Configuration

LeetCode Mode: Auto-Indent Handling

Timing Examples

Cancellation

Usage in Tabby

Performance

Implementation Reference

​Why Typewriter Mode?

​Typing Modes

​Simple Typewriter

​LeetCode Typewriter

​Human Typing Simulation

​Realistic Typos

​Variable Timing

​Default Configuration

​LeetCode Mode: Auto-Indent Handling

​Timing Examples

​Cancellation

​Usage in Tabby

​Performance

​Implementation Reference

​Related Features

Why Typewriter Mode?

Typing Modes

Simple Typewriter

LeetCode Typewriter

Human Typing Simulation

Realistic Typos

Variable Timing

Default Configuration

LeetCode Mode: Auto-Indent Handling

Timing Examples

Cancellation

Usage in Tabby

Performance

Implementation Reference

Related Features