Struct LaunchOptions 

pub struct LaunchOptions {

    pub engine: EngineType,
    pub webdriver: WebDriverOptions,
    pub launch: LaunchMode,
    pub user_data_dir: Option<PathBuf>,
    pub default_browser_check: Option<bool>,
    pub first_run: bool,
    pub preferences: Value,
    pub local_state: Value,
    pub storage_state: Option<StorageStateInput>,
    pub headless: bool,
    pub slow_mo: u64,
    pub verbose: bool,
    pub restrictions: Vec<String>,
    pub args: Vec<String>,
    pub extra_args: Vec<String>,
    pub ignore_default_args: Vec<String>,
    pub ignore_all_default_args: bool,
    pub env: Option<HashMap<String, String>>,
    pub channel: Option<String>,
    pub executable_path: Option<PathBuf>,
    pub remote_debugging_port: Option<u16>,
    pub color_scheme: Option<ColorScheme>,
    pub launch_timeout: Option<Duration>,
    pub sandbox: bool,
    pub node_executable: Option<PathBuf>,
    pub node_working_dir: Option<PathBuf>,
    pub automation_parity: bool,
    pub fingerprint: Option<FingerprintProfile>,
    pub downloads: DownloadSetting,
}

Options for launching a browser.

Fields

engine: EngineType

The browser engine to use.

webdriver: WebDriverOptions

Native WebDriver driver selection and W3C capabilities. Common launch settings below override their corresponding WebDriver settings.

launch: LaunchMode

Who starts the browser; LaunchMode::Real by default.

user_data_dir: Option<PathBuf>

Persistent profile directory. When None a fresh temporary profile is created for the launch and deleted by LaunchResult::close.

default_browser_check: Option<bool>

Allow the disposable browser to ask to become the system default.

first_run: bool

Allow first-run UI in a fresh profile.

preferences: Value

Preferences merged into Default/Preferences before launch.

local_state: Value

Preferences merged into Local State before launch.

storage_state: Option<StorageStateInput>

Playwright-compatible cookie and localStorage state to restore.

headless: bool

Run in headless mode.

slow_mo: u64

Slow down operations by this many milliseconds (default 0).

verbose: bool

Enable verbose logging.

restrictions: Vec<String>

Opt-in restrictions from launch-restrictions.json, such as no-extensions or the legacy-defaults preset (issue #103).

args: Vec<String>

Additional Chrome arguments.

extra_args: Vec<String>

Additional Chrome arguments appended after the compatibility args.

ignore_default_args: Vec<String>

Engine default switches to omit (LaunchMode::Engine only).

ignore_all_default_args: bool

Omit every engine default switch (LaunchMode::Engine only).

env: Option<HashMap<String, String>>

Extra environment for the browser process only; the parent’s environment is never modified.

channel: Option<String>

Installed browser channel, such as chrome, chrome-beta, msedge, brave or chromium.

executable_path: Option<PathBuf>

Explicit path to a Chrome or Chromium executable.

remote_debugging_port: Option<u16>

Fixed CDP port for the real launch; a free one is reserved when None.

color_scheme: Option<ColorScheme>

Color scheme to emulate. None uses the system default.

launch_timeout: Option<Duration>

Optional timeout for the browser launch handshake.

sandbox: bool

Whether to run the browser with the Chromium sandbox enabled.

Defaults to true. Disable when running in environments where the sandbox is unavailable (e.g. CI containers without the required capabilities). This adds --no-sandbox.

node_executable: Option<PathBuf>

Node.js executable for Playwright/Puppeteer fallback engines.

node_working_dir: Option<PathBuf>

Working directory used to resolve Playwright/Puppeteer Node packages.

automation_parity: bool

Keep navigator.webdriver false where a launch switch would turn it on (headless or engine launches).

Defaults to true. Set to false to launch with the engine’s own defaults, which is what the parity tests use as a negative control.

fingerprint: Option<FingerprintProfile>

The environment pages should see: user agent, time zone, locale, core count, screen and the rest.

Applied over CDP once the browser is up, so it only works for the chromiumoxide engine; see fingerprint::profile for the field list and presets for ready-made machines.

downloads: DownloadSetting

Manage the browser’s downloads: where they are saved, how they are named, and whether they outlive the browser.

Downloads are redirected over CDP, so this only works for the chromiumoxide engine; the other engines refuse rather than accept a setting they cannot honor. See downloads.

Implementations

impl LaunchOptions

pub fn engine(self, engine: EngineType) -> Self

Set the browser automation engine.

pub fn storage_state(self, state: impl Into<StorageStateInput>) -> Self

Restore portable session state before the first caller navigation.

pub fn chromiumoxide() -> Self

Create options for chromiumoxide engine.

pub fn fantoccini() -> Self

Create options for fantoccini (WebDriver) engine.

pub fn playwright() -> Self

Create options for Playwright through the Node.js CLI bridge.

pub fn puppeteer() -> Self

Create options for Puppeteer through the Node.js CLI bridge.

pub fn launch(self, launch: LaunchMode) -> Self

Choose who starts the browser.

pub fn headless(self, headless: bool) -> Self

Set headless mode.

pub fn user_data_dir(self, dir: impl Into<PathBuf>) -> Self

Use a persistent profile directory instead of a temporary one.

pub fn slow_mo(self, ms: u64) -> Self

Set slow motion delay.

pub fn verbose(self, verbose: bool) -> Self

Enable verbose logging.

pub fn restrictions<I, S>(self, restrictions: I) -> Self

where I: IntoIterator<Item = S>, S: Into<String>,

Opt in to restrictions or presets from launch-restrictions.json.

pub fn with_args(self, args: Vec<String>) -> Self

Add additional Chrome arguments.

pub fn with_extra_args(self, args: Vec<String>) -> Self

Add Chrome arguments after the compatibility args field.

pub fn ignore_default_args(self, args: Vec<String>) -> Self

Omit selected engine default switches (LaunchMode::Engine only).

pub fn ignore_all_default_args(self) -> Self

Omit every engine default switch (LaunchMode::Engine only).

pub fn env(self, env: HashMap<String, String>) -> Self

Extra environment for the browser process only.

pub fn channel(self, channel: impl Into<String>) -> Self

Select an installed browser channel.

pub fn executable_path(self, executable_path: impl Into<PathBuf>) -> Self

Select an explicit Chrome or Chromium executable.

pub fn remote_debugging_port(self, port: u16) -> Self

Use a fixed CDP port for the real launch.

pub fn color_scheme(self, color_scheme: ColorScheme) -> Self

Set the color scheme for media emulation.

pub fn launch_timeout(self, timeout: Duration) -> Self

Override the browser launch timeout.

pub fn sandbox(self, sandbox: bool) -> Self

Enable or disable the Chromium sandbox for the launched browser.

pub fn node_executable(self, executable: impl Into<PathBuf>) -> Self

Override the Node.js executable used by Playwright/Puppeteer engines.

pub fn node_working_dir(self, dir: impl Into<PathBuf>) -> Self

Set the directory where Node resolves playwright or puppeteer.

pub fn automation_parity(self, automation_parity: bool) -> Self

Turn fingerprint parity with a hand-started Chrome on or off.

pub fn fingerprint(self, fingerprint: FingerprintProfile) -> Self

Set the environment pages should see.

pub fn downloads(self, downloads: impl Into<DownloadSetting>) -> Self

Manage this browser’s downloads.

Arguments

• downloads - true for the defaults, false for none, or DownloadOptions

pub fn all_chrome_args(&self) -> Result<Vec<String>>

The Chrome arguments an engine launch passes: the opt-in restrictions, then args and extra_args, with repeated feature-list switches merged and, with automation parity, the AutomationControlled off switch the engine’s own switches need.

Browser Commander adds nothing else since issue #103; the old defaults are the legacy-defaults restriction preset.

Errors

Returns an error for an unknown restriction.

pub fn all_ignored_default_args(&self) -> Vec<String>

Engine default switches to suppress so the command line matches a hand-started Chrome (LaunchMode::Engine only).

Merged with the caller’s ignore_default_args, because a switch the engine appends after the caller’s arguments cannot be countered by passing a different value for it.

pub fn get_user_data_dir(&self) -> PathBuf

👎Deprecated since 0.13.0:

launch_browser uses a fresh temporary profile unless user_data_dir is set; read LaunchResult::browser.user_data_dir

Get the user data directory, using a default if not specified.

Trait Implementations

impl Clone for LaunchOptions

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LaunchOptions

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LaunchOptions

fn default() -> Self

Returns the “default value” for a type.