Browsers

Browser sessions

Unless otherwise noted, id arguments refer to the browser session ID, not invocation IDs returned by Kernel commands.

kernel browsers list

List all browser sessions.

Flag	Description
--output json, -o json	Output raw JSON array.

kernel browsers create

Create a new browser session.

Flag	Description
--stealth	Enable stealth mode to reduce automation fingerprints.
--headless	Launch without GUI/VNC access.
--kiosk	Launch in Chrome kiosk mode.
--start-url <url>	Initial page to open on launch.
--telemetry <spec>	Configure telemetry (opt-in): all for the default set, off to disable, or a comma-separated category list like console,network.
--output json, -o json	Output raw JSON object.

kernel browsers delete <session-id>

Delete a browser session. Use -y to skip confirmation.

Flag	Description
--yes, -y	Bypass the confirmation prompt.

kernel browsers view <session-id>

Return a live view URL for remote monitoring and control.

Flag	Description
--output json, -o json	Output JSON with liveViewUrl field.

kernel browsers get <session-id>

Get detailed information about a browser session.

Flag	Description
--output json, -o json	Output raw JSON object.

kernel browsers update <session-id>

Update a running browser session — change or remove its proxy, load a profile, resize the viewport, or toggle telemetry.

Flag	Description
--proxy-id <id>	Set the proxy for the session.
--clear-proxy	Remove the proxy from the session.
--profile-id <id>	Load a profile by ID (only into a session without one).
--profile-name <name>	Load a profile by name (mutually exclusive with --profile-id).
--save-changes	Save changes back to the profile when the session ends.
--viewport <WxH@fps>	Set viewport size (e.g. 1920x1080@25).
--force	Force a viewport resize even during an active live view or recording.
--telemetry <spec>	Update telemetry: all resets to the default set, off disables, or a comma-separated list like console,network to merge those categories into the current selection.
--disable-default-proxy	Disable the default stealth proxy so the browser connects directly. Pass --disable-default-proxy=false to re-enable it.
--output json, -o json	Output raw API response as JSON.

kernel browsers curl <session-id> <url>

Make an HTTP request through the browser’s network stack, inheriting its TLS fingerprint, cookies, proxy, and headers. Works like curl, but requests go through the browser session. See Browser curl for examples.

Flag	Description
--request <method>, -X	HTTP method (default: GET).
--header <"Key: Value">, -H	Add a request header (repeatable).
--data <body>, -d	Request body.
--data-file <path>	Read the request body from a file.
--head, -I	Fetch headers only.
--include, -i	Include response headers in the output.
--dump-header <path>, -D	Write received headers to a file (- for stdout).
--output <path>, -o	Write the response body to a file.
--fail, -f	Fail with no body output on HTTP errors.
--silent, -s	Suppress progress output.
--max-time <seconds>	Maximum time allowed for the request (default: 30).
--write-out <format>, -w	Print text after completion (supports %{http_code}, %{time_total}, %{size_download}).

kernel browsers ssh <session-id>

Open an interactive SSH session to a browser VM. Requires websocat to be installed locally.

Flag	Description
-i, --identity <path>	Path to SSH private key (generates ephemeral if not provided).
-L, --local-forward <spec>	Local port forwarding (localport:host:remoteport).
-R, --remote-forward <spec>	Remote port forwarding (remoteport:host:localport).
--setup-only	Setup SSH on VM without connecting.

Browser logs

kernel browsers logs stream <session-id>

Stream browser logs from the supervisor or a file path.

Flag	Description
--source <source>	path or supervisor (required).
--follow	Continue streaming (default: true).
--path <path>	File path when --source=path.
--supervisor-process <name>	Supervisor process when --source=supervisor (e.g. chromium).

Log lines longer than 64 KiB are truncated.

Telemetry

kernel browsers telemetry stream <session-id>

Stream live telemetry events from a browser session. Filters are applied client-side and don’t change what the session captures.

Flag	Description
--categories <list>	Filter by category: console, network, page, interaction, control, connection, system, screenshot, captcha, monitor.
--types <list>	Filter by event type (e.g. network_response,console_error).
--seq <n>	Resume after sequence number N; replays events with seq > N (default: -1, stream from now).
--output json, -o json	Output newline-delimited JSON envelopes.

Replays

kernel browsers replays list <session-id>

List replay recordings for a browser session.

Flag	Description
--output json, -o json	Output raw JSON array.

kernel browsers replays start <session-id>

Start recording a replay.

Flag	Description
--framerate <fps>	Recording framerate in frames per second.
--max-duration <seconds>	Maximum recording duration.
--output json, -o json	Output raw JSON object.

kernel browsers replays stop <session-id> <replay-id>

Stop an active replay recording.

kernel browsers replays download <session-id> <replay-id>

Download a replay video.

Flag	Description
-o, --output <path>	Output path for the downloaded replay.

Process control

kernel browsers process exec <session-id> [--] [command...]

Execute a command synchronously inside the browser VM.

Flag	Description
--command <cmd>	Command to run; defaults to trailing args.
--args <args>	Arguments for the command.
--cwd <path>	Working directory.
--timeout <seconds>	Execution timeout.
--as-user <user>	Run as a specific user.
--as-root	Run as root.
--env <KEY=VALUE>	Set an environment variable for the process (repeatable).
--output json, -o json	Output raw JSON object.

kernel browsers process spawn <session-id> [--] [command...]

Execute a command asynchronously in the browser VM.

Flag	Description
--command <cmd>	Command to run; defaults to trailing args.
--args <args>	Arguments for the command.
--cwd <path>	Working directory.
--timeout <seconds>	Execution timeout.
--as-user <user>	Run as a specific user.
--as-root	Run as root.
--env <KEY=VALUE>	Set an environment variable for the process (repeatable).
--allocate-tty	Allocate a pseudo-terminal (PTY) for interactive shells.
--cols <n>	Set the initial terminal columns. Requires --allocate-tty.
--rows <n>	Set the initial terminal rows. Requires --allocate-tty.
--output json, -o json	Output raw JSON object.

kernel browsers process kill <session-id> <process-id>

Send a signal to a process running in the browser VM.

Flag	Description
--signal <signal>	Signal to send (TERM, KILL, INT, HUP; default: TERM).

kernel browsers process status <session-id> <process-id>

Check process status information.

kernel browsers process stdin <session-id> <process-id>

Write base64-encoded data to a process stdin.

Flag	Description
--data-b64 <data>	Base64 payload to write (required).

kernel browsers process stdout-stream <session-id> <process-id>

Stream stdout and stderr from a process.

Filesystem

kernel browsers fs new-directory <session-id>

Create a directory in the browser VM.

Flag	Description
--path <path>	Absolute directory path to create (required).
--mode <mode>	Directory mode in octal.

kernel browsers fs delete-directory <session-id>

Delete a directory.

Flag	Description
--path <path>	Absolute directory path to delete (required).

kernel browsers fs delete-file <session-id>

Delete a file.

Flag	Description
--path <path>	Absolute file path to delete (required).

kernel browsers fs download-dir-zip <session-id>

Download a directory as a zip archive.

Flag	Description
--path <path>	Absolute directory path to download (required).
-o, --output <path>	Output zip file path.

kernel browsers fs file-info <session-id>

Retrieve metadata for a file or directory.

Flag	Description
--path <path>	Absolute file or directory path (required).
--output json, -o json	Output raw JSON object.

kernel browsers fs list-files <session-id>

List directory contents.

Flag	Description
--path <path>	Absolute directory path (required).
--output json, -o json	Output raw JSON array.

kernel browsers fs move <session-id>

Move or rename a file or directory.

Flag	Description
--src <path>	Absolute source path (required).
--dest <path>	Absolute destination path (required).

kernel browsers fs read-file <session-id>

Read a file from the browser VM.

Flag	Description
--path <path>	Absolute file path (required).
-o, --output <path>	Output path for the downloaded file.

kernel browsers fs set-permissions <session-id>

Update file permissions or ownership.

Flag	Description
--path <path>	Absolute path (required).
--mode <mode>	File mode bits (octal string).
--owner <user>	New owner username or UID.
--group <group>	New group name or GID.

kernel browsers fs upload <session-id>

Upload one or more files.

Flag	Description
--file <local:remote>	Local-to-remote file mapping (repeatable).
--dest-dir <path>	Destination directory for uploads.
--paths <paths>	Local file paths to upload.

kernel browsers fs upload-zip <session-id>

Upload a zip file and extract it.

Flag	Description
--zip <path>	Local zip file path (required).
--dest-dir <path>	Directory to extract into (required).

kernel browsers fs write-file <session-id>

Write a local file to the browser VM.

Flag	Description
--path <path>	Destination absolute file path (required).
--mode <mode>	File mode in octal.
--source <path>	Local source file path (required).

Computer controls

kernel browsers computer click-mouse <session-id>

Click the mouse at specific coordinates.

Flag	Description
--x <coordinate>	X coordinate (required).
--y <coordinate>	Y coordinate (required).
--num-clicks <n>	Number of clicks (default: 1).
--button <button>	Mouse button (left, right, middle, back, forward).
--click-type <type>	down, up, or click (default: click).
--hold-key <key>	Modifier keys to hold (repeatable).

kernel browsers computer move-mouse <session-id>

Move the mouse pointer.

Flag	Description
--x <coordinate>	X coordinate (required).
--y <coordinate>	Y coordinate (required).
--hold-key <key>	Modifier keys to hold (repeatable).

kernel browsers computer screenshot <session-id>

Capture a screenshot.

Flag	Description
--to <path>	Output PNG path (required).
--x <coordinate>	Region capture top-left X coordinate.
--y <coordinate>	Region capture top-left Y coordinate.
--width <pixels>	Region width.
--height <pixels>	Region height.

kernel browsers computer type <session-id>

Type text into the browser VM.

Flag	Description
--text <text>	Text to type (required).
--delay <ms>	Delay between keystrokes in milliseconds.

kernel browsers computer press-key <session-id>

Press one or more keys.

Flag	Description
--key <key>	Key to press (repeatable).
--duration <ms>	Duration to hold keys.
--hold-key <key>	Modifier keys to hold (repeatable).

kernel browsers computer scroll <session-id>

Scroll the mouse wheel.

Flag	Description
--x <coordinate>	X coordinate (required).
--y <coordinate>	Y coordinate (required).
--delta-x <pixels>	Horizontal scroll amount (+right, -left).
--delta-y <pixels>	Vertical scroll amount (+down, -up).
--hold-key <key>	Modifier keys to hold (repeatable).

kernel browsers computer drag-mouse <session-id>

Drag the mouse along a path.

Flag	Description
--point <x,y>	Points to drag through (repeatable).
--delay <ms>	Delay before dragging starts.
--button <button>	Mouse button (left, middle, right; default: left).
--hold-key <key>	Modifier keys to hold (repeatable).

Playwright

kernel browsers playwright execute <session-id> [code]

Execute Playwright/TypeScript code against a running browser session.

Flag	Description
--timeout <seconds>	Maximum execution time for the snippet.

WebMCP

These commands require CLI v0.41.0 or later. See the WebMCP guide and custom WebMCP tools.

kernel browsers webmcp list <session-id>

List native and custom WebMCP tools across every tab and frame in the browser.

Flag	Description
--exclude-custom	List only tools the pages registered.
--output json, -o json	Output the raw API response.

kernel browsers webmcp invoke <session-id>

Invoke one tool by its tool_ref. The CLI doesn’t retry invocations automatically.

Flag	Description
--tool-ref <ref>	Opaque tool_ref from the latest webmcp list output. Required.
--input <json>	Tool input as a JSON object.
--input-file <path>	Read the input object from a file (use - for stdin).
--timeout-sec <seconds>	Maximum invocation time, from 1 to 120. Defaults to 60.

kernel browsers webmcp custom-tools list <session-id>

List registered custom tool definitions, including ones that don’t currently match an open page.

Flag	Description
--output json, -o json	Output the raw API response.

kernel browsers webmcp custom-tools add <session-id>

Register a namespaced batch of custom tools from a JavaScript source file. The CLI doesn’t retry registration automatically.

Flag	Description
--namespace <namespace>	Namespace for the batch: 1–128 letters, digits, dots, underscores, or hyphens. Required.
--source-file <path>	JavaScript source that evaluates to an array of tool definitions (use - for stdin). Required.
--force-overwrite-namespace	Atomically replace every existing tool in the namespace.
--output json, -o json	Output the raw API response.

For example, to register the tools from hn-tools.js:

kernel browsers webmcp custom-tools add hn-reader \
  --namespace news.ycombinator.com \
  --source-file hn-tools.js

kernel browsers webmcp custom-tools remove <session-id> <tool-id>

Remove one custom tool definition by its generated ct_… ID. Invocations already in progress keep running.

Extension management

kernel extensions list

List all uploaded extensions.

Flag	Description
--output json, -o json	Output raw JSON array.

kernel extensions upload <directory>

Upload an unpacked extension directory.

Flag	Description
--name <name>	Optional unique extension name.
--output json, -o json	Output raw JSON object.

kernel extensions download <id-or-name>

Download an extension archive.

Flag	Description
--to <directory>	Output directory (required).

kernel extensions download-web-store <url>

Download an extension from the Chrome Web Store.

Flag	Description
--to <directory>	Output directory (required).
--os <os>	Target OS (mac, win, linux; default: linux).

kernel extensions delete <id-or-name>

Delete an uploaded extension.

Flag	Description
--yes, -y	Skip confirmation.

kernel browsers extensions upload <session-id> <extension-path>...

Upload one or more unpacked Chrome extensions directly into a running browser session.