Struct ClientBuilder 

pub struct ClientBuilder { /* private fields */ }

Configures and bootstraps a GuerrillaMail Client.

Conceptually, ClientBuilder holds request-layer options (proxy, TLS leniency, user agent, endpoints, timeout). Calling build creates a reqwest::Client with cookie storage enabled, fetches the GuerrillaMail homepage once, and captures the ApiToken … header needed for all later AJAX calls.

Invariants/internal behavior:

• The bootstrap fetch happens exactly once during build; the resulting token is baked into the constructed Client.
• Defaults favor easy testing: no proxy, danger_accept_invalid_certs = true, browser-like user agent, 30s timeout, and the public GuerrillaMail endpoints.
• Clone is cheap and copies configuration only; it does not perform additional network I/O.

Typical lifecycle: start with Client::builder, adjust options, call build, then discard the builder. Reuse the built Client (or its cheap clones) across tasks.

Example

let client = Client::builder()
    .proxy("http://127.0.0.1:8080")
    .danger_accept_invalid_certs(false)
    .user_agent("my-app/2.0")
    .build()
    .await?;

Implementations

impl ClientBuilder

pub fn new() -> Self

Create a new builder with default settings.

See ClientBuilder for the list of defaults.

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

Set a proxy URL (e.g. "http://127.0.0.1:8080").

The proxy is applied to all requests performed by the underlying reqwest::Client.

pub fn danger_accept_invalid_certs(self, value: bool) -> Self

Configure whether to accept invalid TLS certificates (default: true).

Set this to false for stricter TLS verification.

Security

Accepting invalid certificates is unsafe on untrusted networks; it is primarily useful for debugging or traffic inspection in controlled environments.

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

Override the default user agent string.

GuerrillaMail may apply different behavior based on the UA; the default is a browser-like value.

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

Override the GuerrillaMail AJAX endpoint URL.

This is primarily useful for testing or if GuerrillaMail changes its endpoint.

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

Override the GuerrillaMail base URL.

This is primarily useful for testing.

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

Override the default request timeout.

The timeout applies to the whole request (connect + read), matching reqwest::ClientBuilder::timeout. Defaults to 30 seconds.

pub async fn build(self) -> Result<Client>

Build the Client by performing the GuerrillaMail bootstrap request.

Constructs a reqwest::Client with cookie storage, applies the configured proxy/TLS/user agent/timeouts, sends one GET to the GuerrillaMail homepage, and extracts the ApiToken … header required for later AJAX calls.

Errors

• Returns Error::Request for HTTP client build issues, bootstrap network failures, or non-2xx responses.
• Returns Error::TokenParse when the API token cannot be found in the bootstrap HTML.
• Returns Error::HeaderValue if the token cannot be encoded into the authorization header. Network-related failures are transient; token/header errors likely indicate a page layout change.

Network

Issues one GET request to the configured base_url.

Examples

let client = Client::builder()
    .user_agent("my-app/1.0")
    .build()
    .await?;

Trait Implementations

impl Clone for ClientBuilder

fn clone(&self) -> ClientBuilder

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClientBuilder

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

Formats the value using the given formatter.

impl Default for ClientBuilder

fn default() -> Self

Returns the “default value” for a type.