Computer Controls

Control the computer’s mouse, keyboard, and screen

Use OS-level controls to move and click the mouse, type and press keys, scroll, drag, and capture screenshots from a running browser session. Both moveMouse and dragMouse use human-like Bézier curves by default.

Click the mouse

Simulate mouse clicks at specific coordinates. You can select the button, click type (down, up, click), number of clicks, and optional modifier keys to hold.

Typescript/Javascript

import Kernel from '@onkernel/sdk';

const kernel = new Kernel();
const kernelBrowser = await kernel.browsers.create();

// Basic left click at (100, 200)
await kernel.browsers.computer.clickMouse(kernelBrowser.session_id, {
  x: 100,
  y: 200,
});

// Double right-click while holding Shift
await kernel.browsers.computer.clickMouse(kernelBrowser.session_id, {
  x: 100,
  y: 200,
  button: 'right',
  click_type: 'click',
  num_clicks: 2,
  hold_keys: ['Shift'],
});

from kernel import Kernel

kernel = Kernel()
kernel_browser = kernel.browsers.create()

# Basic left click at (100, 200)
kernel.browsers.computer.click_mouse(
    id=kernel_browser.session_id,
    x=100,
    y=200,
)

# Double right-click while holding Shift
kernel.browsers.computer.click_mouse(
    id=kernel_browser.session_id,
    x=100,
    y=200,
    button="right",
    click_type="click",
    num_clicks=2,
    hold_keys=["Shift"],
)

# Click the mouse at coordinates (100, 200)
kernel browsers computer click-mouse <session id> --x 100 --y 200

# Double-click the right mouse button
kernel browsers computer click-mouse <session id> --x 100 --y 200 --num-clicks 2 --button right

Move the mouse

Move the cursor to specific screen coordinates. By default, the cursor follows a human-like Bezier curve path instead of teleporting instantly. You can control this with smooth and duration_ms.

Parameter	Type	Default	Description
x	integer	—	X coordinate to move the cursor to
y	integer	—	Y coordinate to move the cursor to
smooth	boolean	true	Use human-like Bezier curve path instead of instant teleport
duration_ms	integer	auto	Target duration in milliseconds for smooth movement (50–5000). Omit for automatic timing based on distance
hold_keys	array	—	Modifier keys to hold during the move

Typescript/Javascript

import Kernel from '@onkernel/sdk';

const kernel = new Kernel();
const kernelBrowser = await kernel.browsers.create();

// Human-like smooth movement (default)
await kernel.browsers.computer.moveMouse(kernelBrowser.session_id, {
  x: 500,
  y: 300,
});

// Smooth movement with custom duration
await kernel.browsers.computer.moveMouse(kernelBrowser.session_id, {
  x: 800,
  y: 600,
  smooth: true,
  duration_ms: 1500,
});

// Instant teleport (disable smooth)
await kernel.browsers.computer.moveMouse(kernelBrowser.session_id, {
  x: 100,
  y: 200,
  smooth: false,
});

from kernel import Kernel

kernel = Kernel()
kernel_browser = kernel.browsers.create()

# Human-like smooth movement (default)
kernel.browsers.computer.move_mouse(
    id=kernel_browser.session_id,
    x=500,
    y=300,
)

# Smooth movement with custom duration
kernel.browsers.computer.move_mouse(
    id=kernel_browser.session_id,
    x=800,
    y=600,
    smooth=True,
    duration_ms=1500,
)

# Instant teleport (disable smooth)
kernel.browsers.computer.move_mouse(
    id=kernel_browser.session_id,
    x=100,
    y=200,
    smooth=False,
)

# Smooth movement (default)
kernel browsers computer move-mouse <session id> --x 500 --y 300

# Instant teleport
kernel browsers computer move-mouse <session id> --x 500 --y 300 --smooth=false

Smooth vs instant movement

Take screenshots

Capture a full-screen PNG or a specific region.

For WebGL and other animation-heavy pages, captureScreenshot is noticeably faster than CDP’s Page.captureScreenshot. If you’re driving a computer-use loop off screenshots, prefer computer controls. GPU acceleration gives an additional small speedup for computer controls screenshots, but does not speed up CDP screenshots.

Typescript/Javascript

import fs from 'fs';
import { Buffer } from 'buffer';
import Kernel from '@onkernel/sdk';

const kernel = new Kernel();
const kernelBrowser = await kernel.browsers.create();

// Full screenshot
{
  const response = await kernel.browsers.computer.captureScreenshot(kernelBrowser.session_id);
  const blob = await response.blob();
  const buffer = Buffer.from(await blob.arrayBuffer());
  fs.writeFileSync('screenshot.png', buffer);
}

// Region screenshot
{
  const response = await kernel.browsers.computer.captureScreenshot(kernelBrowser.session_id, {
    region: { x: 0, y: 0, width: 800, height: 600 },
  });
  const blob = await response.blob();
  const buffer = Buffer.from(await blob.arrayBuffer());
  fs.writeFileSync('region.png', buffer);
}

from kernel import Kernel

kernel = Kernel()
kernel_browser = kernel.browsers.create()

# Full screenshot
with open('screenshot.png', 'wb') as f:
    image_data = kernel.browsers.computer.capture_screenshot(id=kernel_browser.session_id)
    f.write(image_data.read())

# Region screenshot
with open('region.png', 'wb') as f:
    image_data = kernel.browsers.computer.capture_screenshot(
        id=kernel_browser.session_id,
        region={"x": 0, "y": 0, "width": 800, "height": 600},
    )
    f.write(image_data.read())

# Take a full screenshot
kernel browsers computer screenshot <session id> --to screenshot.png

# Take a screenshot of a specific region
kernel browsers computer screenshot <session id> --to region.png --x 0 --y 0 --width 800 --height 600

Type text

Type literal text on the host. By default, typing uses human-like variable timing: word-sized chunks, natural pauses at word and sentence boundaries, and optional realistic typos corrected with backspace. Set smooth: false for xdotool typing with a fixed per-keystroke delay (delay, in ms) or instant input when delay is 0.

Parameter	Type	Default	Description
text	string	—	Text to type
delay	integer	0	Fixed delay in milliseconds between keystrokes. Only used when smooth is false; ignored when smooth is true
smooth	boolean	true	Human-like variable keystroke timing with word-boundary pauses (default, same idea as moveMouse / dragMouse)
typo_chance	number	0	Per-character typo rate from 0–0.10 (capped; 0.10 ≈ 10% per character on average), corrected with backspace. Only applies when smooth is true (silently ignored when smooth is false). Typical values are 0.02–0.05

Typescript/Javascript

import Kernel from '@onkernel/sdk';

const kernel = new Kernel();
const kernelBrowser = await kernel.browsers.create();

// Human-like smooth typing (default — omit smooth or pass true)
await kernel.browsers.computer.typeText(kernelBrowser.session_id, {
  text: 'The quick brown fox jumps over the lazy dog.',
});

// Human-like with occasional typos (3% chance per character)
await kernel.browsers.computer.typeText(kernelBrowser.session_id, {
  text: 'The quick brown fox jumps over the lazy dog.',
  typo_chance: 0.03,
});

// Instant typing (all at once, no per-key delay)
await kernel.browsers.computer.typeText(kernelBrowser.session_id, {
  text: 'Hello, World!',
  smooth: false,
});

// Fixed delay between keystrokes (smooth off)
await kernel.browsers.computer.typeText(kernelBrowser.session_id, {
  text: 'Slow typing...',
  smooth: false,
  delay: 100,
});

from kernel import Kernel

kernel = Kernel()
kernel_browser = kernel.browsers.create()

# Human-like smooth typing (default — omit smooth or pass True)
kernel.browsers.computer.type_text(
    id=kernel_browser.session_id,
    text="The quick brown fox jumps over the lazy dog.",
)

# Human-like with occasional typos (3% chance per character)
kernel.browsers.computer.type_text(
    id=kernel_browser.session_id,
    text="The quick brown fox jumps over the lazy dog.",
    typo_chance=0.03,
)

# Instant typing (all at once, no per-key delay)
kernel.browsers.computer.type_text(
    id=kernel_browser.session_id,
    text="Hello, World!",
    smooth=False,
)

# Fixed delay between keystrokes (smooth off)
kernel.browsers.computer.type_text(
    id=kernel_browser.session_id,
    text="Slow typing...",
    smooth=False,
    delay=100,
)

# Human-like smooth typing (default)
kernel browsers computer type <session id> --text "The quick brown fox"

# Human-like with occasional typos
kernel browsers computer type <session id> --text "The quick brown fox" --typo-chance 0.03

# Instant typing (all at once)
kernel browsers computer type <session id> --text "Hello, World!" --smooth=false

# Fixed delay between keystrokes (smooth off)
kernel browsers computer type <session id> --text "Slow typing..." --smooth=false --delay 100

Smooth vs instant typing

Press keys

Press one or more key symbols (including combinations like “Ctrl+t” or “Ctrl+Shift+Tab”). Optionally hold modifiers and/or set a duration to hold keys down.

Typescript/Javascript

import Kernel from '@onkernel/sdk';

const kernel = new Kernel();
const kernelBrowser = await kernel.browsers.create();

// Tap a key combination
await kernel.browsers.computer.pressKey(kernelBrowser.session_id, {
  keys: ['Ctrl+t'],
});

// Hold keys for 250ms while also holding Alt
await kernel.browsers.computer.pressKey(kernelBrowser.session_id, {
  keys: ['Ctrl+Shift+Tab'],
  duration: 250,
  hold_keys: ['Alt'],
});

from kernel import Kernel

kernel = Kernel()
kernel_browser = kernel.browsers.create()

# Tap a key combination
kernel.browsers.computer.press_key(
    id=kernel_browser.session_id,
    keys=["Ctrl+t"],
)

# Hold keys for 250ms while also holding Alt
kernel.browsers.computer.press_key(
    id=kernel_browser.session_id,
    keys=["Ctrl+Shift+Tab"],
    duration=250,
    hold_keys=["Alt"],
)

# Press one or more keys (repeatable --key)
kernel browsers computer press-key <session id> --key Ctrl+t

# Hold for a duration and add optional modifiers
kernel browsers computer press-key <session id> --key Ctrl+Shift+Tab --duration 250 --hold-key Alt

Scroll

Scroll the mouse wheel at a specific position. Positive delta_y scrolls down; negative scrolls up. Positive delta_x scrolls right; negative scrolls left. Scroll amounts refer to “wheel units.”

Typescript/Javascript

import Kernel from '@onkernel/sdk';

const kernel = new Kernel();
const kernelBrowser = await kernel.browsers.create();

await kernel.browsers.computer.scroll(kernelBrowser.session_id, {
  x: 300,
  y: 400,
  delta_x: 0,
  delta_y: 120,
});

from kernel import Kernel

kernel = Kernel()
kernel_browser = kernel.browsers.create()

kernel.browsers.computer.scroll(
    id=kernel_browser.session_id,
    x=300,
    y=400,
    delta_x=0,
    delta_y=120,
)

# Scroll at a position
kernel browsers computer scroll <session id> --x 300 --y 400 --delta-y 120

Drag the mouse

Drag by pressing a button, moving along a path of points, then releasing. By default, drag movement uses human-like Bezier curves between waypoints. Set smooth: false to use linear interpolation with steps_per_segment and step_delay_ms instead.

Parameter	Type	Default	Description
path	array	—	Ordered list of [x, y] coordinate pairs to move through (minimum 2 points)
button	string	left	Mouse button: left, middle, or right
smooth	boolean	true	Use human-like Bezier curves between waypoints. When true, steps_per_segment and step_delay_ms are ignored
duration_ms	integer	auto	Target duration in milliseconds for the entire drag when smooth=true (50–10000). Omit for automatic timing based on total path length
delay	integer	0	Delay in milliseconds between button down and starting to move
steps_per_segment	integer	10	Number of interpolation steps per path segment (only when smooth=false)
step_delay_ms	integer	50	Delay in milliseconds between steps (only when smooth=false)
hold_keys	array	—	Modifier keys to hold during the drag

Smooth vs linear drag

Typescript/Javascript

import Kernel from '@onkernel/sdk';

const kernel = new Kernel();
const kernelBrowser = await kernel.browsers.create();

// Human-like smooth drag (default)
await kernel.browsers.computer.dragMouse(kernelBrowser.session_id, {
  path: [
    [100, 200],
    [400, 350],
    [700, 200],
  ],
});

// Smooth drag with custom duration
await kernel.browsers.computer.dragMouse(kernelBrowser.session_id, {
  path: [
    [100, 200],
    [400, 350],
    [700, 200],
  ],
  smooth: true,
  duration_ms: 2000,
});

// Linear interpolation drag (legacy behavior)
await kernel.browsers.computer.dragMouse(kernelBrowser.session_id, {
  path: [
    [100, 200],
    [400, 350],
    [700, 200],
  ],
  smooth: false,
  steps_per_segment: 10,
  step_delay_ms: 50,
});

from kernel import Kernel

kernel = Kernel()
kernel_browser = kernel.browsers.create()

# Human-like smooth drag (default)
kernel.browsers.computer.drag_mouse(
    id=kernel_browser.session_id,
    path=[[100, 200], [400, 350], [700, 200]],
)

# Smooth drag with custom duration
kernel.browsers.computer.drag_mouse(
    id=kernel_browser.session_id,
    path=[[100, 200], [400, 350], [700, 200]],
    smooth=True,
    duration_ms=2000,
)

# Linear interpolation drag (legacy behavior)
kernel.browsers.computer.drag_mouse(
    id=kernel_browser.session_id,
    path=[[100, 200], [400, 350], [700, 200]],
    smooth=False,
    steps_per_segment=10,
    step_delay_ms=50,
)

# Smooth drag (default)
kernel browsers computer drag-mouse <session id> \
  --point 100,200 \
  --point 400,350 \
  --point 700,200

# Linear interpolation drag
kernel browsers computer drag-mouse <session id> \
  --point 100,200 \
  --point 400,350 \
  --point 700,200 \
  --smooth=false \
  --steps-per-segment 10 \
  --step-delay-ms 50