Struct FetcherConfigBuilder 

pub struct FetcherConfigBuilder { /* private fields */ }

Builder for constructing a FetcherConfig with validation.

The builder provides a fluent API for setting configuration options and catches invalid combinations at build time (e.g., setting both a static proxy and a proxy rotator). Call build() to get the validated config.

let (config, rotator) = FetcherConfigBuilder::new()
    .timeout_secs(10)
    .retries(5)
    .follow_redirects(FollowRedirects::All)
    .build()
    .unwrap();

Implementations

impl FetcherConfigBuilder

pub fn new() -> Self

Creates a new builder pre-populated with the same defaults as FetcherConfig::default() – 30s timeout, 3 retries, Chrome impersonation, etc.

pub fn impersonate(self, imp: Impersonate) -> Self

Sets the browser impersonation profile. See Impersonate for the available strategies (none, single browser, or random rotation).

pub fn stealthy_headers(self, enabled: bool) -> Self

Enables or disables stealth header injection. When enabled, the fetcher adds browser-like headers (Referer, Sec-Fetch-*, etc.) to help bypass bot detection.

pub fn proxy(self, proxy: Proxy) -> Self

Sets a static proxy for all requests. Cannot be combined with proxy_rotator() – the builder will return an error on build() if both are set.

pub fn timeout_secs(self, secs: u64) -> Self

Sets the request timeout in seconds. This covers the entire request lifecycle including DNS, TLS handshake, and body download.

pub fn header(self, name: impl Into<String>, value: impl Into<String>) -> Self

Adds a single default header that will be sent with every request. Call multiple times to add several headers. Per-request headers in RequestConfig take precedence over these.

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

Replaces all default headers with the given map. Any headers previously added with header() are discarded.

pub fn retries(self, retries: u32) -> Self

Sets the maximum number of retry attempts. A value of 1 means the request is tried once with no retries. The default is 3.

pub fn retry_delay_secs(self, secs: u64) -> Self

Sets the fixed delay in seconds between retries. There is no exponential backoff – each retry waits exactly this long.

pub fn follow_redirects(self, policy: FollowRedirects) -> Self

Sets the redirect-following policy. See FollowRedirects for the options.

pub fn max_redirects(self, max: usize) -> Self

Sets the maximum number of redirects to follow. If this limit is exceeded, the request fails with an error rather than looping indefinitely.

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

Enables or disables TLS certificate verification. Disabling this is a security risk and should only be used for testing with self-signed certs.

pub fn proxy_rotator(self, rotator: ProxyRotator) -> Self

Sets a proxy rotator for distributing requests across multiple proxies. Cannot be combined with proxy() – the builder will return an error on build() if both are set.

pub fn build(self) -> Result<(FetcherConfig, Option<ProxyRotator>)>

Validates and builds the configuration, returning a tuple of the config and an optional proxy rotator. Returns an error if both a static proxy and a proxy rotator were configured, since those options are mutually exclusive.

Trait Implementations

impl Default for FetcherConfigBuilder

fn default() -> Self

Returns the “default value” for a type.