Struct LaunchOptions 

pub struct LaunchOptions {

    pub path: PathBuf,
    pub version: String,
    pub authenticator: Authenticator,
    pub timeout_secs: u64,
    pub download_concurrency: u32,
    pub verify_concurrency: u32,
    pub memory: MemoryConfig,
    pub java: JavaOptions,
    pub loader: LoaderConfig,
    pub screen: ScreenConfig,
    pub verify: bool,
    pub game_args: Vec<String>,
    pub jvm_args: Vec<String>,
    pub instance: Option<String>,
    pub url: Option<String>,
    pub mcp: Option<String>,
    pub intel_enabled_mac: bool,
    pub bypass_offline: bool,
}

Complete configuration for a launcher session.

Pass to Launcher::new(). Every field except path, version, and authenticator has a sensible default so callers only need to set what differs from the defaults.

Fields

path: PathBuf

Absolute base path for all launcher data (libraries/, assets/, versions/, runtime/, …).

version: String

Minecraft version: concrete ("1.20.4") or alias ("latest_release" / "r" / "lr" / "latest_snapshot" / "s" / "ls").

authenticator: Authenticator

Authentication credentials — required.

timeout_secs: u64

HTTP request timeout in seconds (default: 10).

download_concurrency: u32

Concurrent download workers, clamped to 1–30 (default: 5).

verify_concurrency: u32

Concurrent SHA-1 verify workers, clamped to 1–16 (default: 4). Lower than download_concurrency to avoid disk seek thrashing on HDDs.

memory: MemoryConfig

java: JavaOptions

loader: LoaderConfig

screen: ScreenConfig

verify: bool

Re-verify SHA-1 integrity of every file after download (default: false).

game_args: Vec<String>

Extra arguments appended after the vanilla game arg list.

jvm_args: Vec<String>

Extra arguments prepended to the JVM arg list.

instance: Option<String>

Named instance for multi-instance support. When set, data lives under <path>/instances/<instance>/.

url: Option<String>

URL for custom additional assets (optional).

mcp: Option<String>

Path to a custom Minecraft JAR (mod compatibility parameter).

intel_enabled_mac: bool

macOS only: force x64 Java even on Apple Silicon (Rosetta 2).

bypass_offline: bool

Redirect Mojang auth endpoints to an invalid domain so offline multiplayer works without a valid session (default: false).

Implementations

impl LaunchOptions

pub fn save_dir(&self) -> PathBuf

Directory where gameData.json is stored. Returns <path>/instances/<instance> when instanced, otherwise <path>.

pub fn loader_dir(&self, name: &str) -> PathBuf

Root directory for a specific mod loader’s files.

Returns <path>/loader/<name> unless loader.path is set explicitly.

pub fn clamped_concurrency(&self) -> u32

download_concurrency clamped to the valid range 1–30.

pub fn clamped_verify_concurrency(&self) -> u32

verify_concurrency clamped to the valid range 1–16.

Trait Implementations

impl Clone for LaunchOptions

fn clone(&self) -> LaunchOptions

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<'de> Deserialize<'de> for LaunchOptions

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for LaunchOptions

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.