Struct reqwest::blocking::ClientBuilder

pub struct ClientBuilder { /* fields omitted */ }

A ClientBuilder can be used to create a Client with custom configuration.

Example

use std::time::Duration;

let client = reqwest::blocking::Client::builder()
    .timeout(Duration::from_secs(10))
    .build()?;

Implementations

impl ClientBuilder

pub fn new() -> ClientBuilder

Constructs a new ClientBuilder.

This is the same as Client::builder().

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

Returns a Client that uses this ClientBuilder configuration.

Errors

This method fails if TLS backend cannot be initialized, or the resolver cannot load the system configuration.

Panics

This method panics if called from within an async runtime. See docs on reqwest::blocking for details.

pub fn user_agent<V>(self, value: V) -> ClientBuilder where
    V: TryInto<HeaderValue>,
    V::Error: Into<Error>, 

Sets the User-Agent header to be used by this client.

Example

// Name your user agent after your app?
static APP_USER_AGENT: &str = concat!(
    env!("CARGO_PKG_NAME"),
    "/",
    env!("CARGO_PKG_VERSION"),
);

let client = reqwest::blocking::Client::builder()
    .user_agent(APP_USER_AGENT)
    .build()?;
let res = client.get("https://www.rust-lang.org").send()?;

pub fn default_headers(self, headers: HeaderMap) -> ClientBuilder

Sets the default headers for every request.

Example

use reqwest::header;
let mut headers = header::HeaderMap::new();
headers.insert("X-MY-HEADER", header::HeaderValue::from_static("value"));
headers.insert(header::AUTHORIZATION, header::HeaderValue::from_static("secret"));

// Consider marking security-sensitive headers with `set_sensitive`.
let mut auth_value = header::HeaderValue::from_static("secret");
auth_value.set_sensitive(true);
headers.insert(header::AUTHORIZATION, auth_value);

// get a client builder
let client = reqwest::blocking::Client::builder()
    .default_headers(headers)
    .build()?;
let res = client.get("https://www.rust-lang.org").send()?;

Override the default headers:

use reqwest::header;
let mut headers = header::HeaderMap::new();
headers.insert("X-MY-HEADER", header::HeaderValue::from_static("value"));

// get a client builder
let client = reqwest::blocking::Client::builder()
    .default_headers(headers)
    .build()?;
let res = client
    .get("https://www.rust-lang.org")
    .header("X-MY-HEADER", "new_value")
    .send()?;

pub fn no_gzip(self) -> ClientBuilder

Disable auto response body gzip decompression.

This method exists even if the optional gzip feature is not enabled. This can be used to ensure a Client doesn’t use gzip decompression even if another dependency were to enable the optional gzip feature.

pub fn no_brotli(self) -> ClientBuilder

Disable auto response body brotli decompression.

This method exists even if the optional brotli feature is not enabled. This can be used to ensure a Client doesn’t use brotli decompression even if another dependency were to enable the optional brotli feature.

pub fn no_deflate(self) -> ClientBuilder

Disable auto response body deflate decompression.

This method exists even if the optional deflate feature is not enabled. This can be used to ensure a Client doesn’t use deflate decompression even if another dependency were to enable the optional deflate feature.

pub fn redirect(self, policy: Policy) -> ClientBuilder

Set a redirect::Policy for this client.

Default will follow redirects up to a maximum of 10.

pub fn referer(self, enable: bool) -> ClientBuilder

Enable or disable automatic setting of the Referer header.

Default is true.

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

Add a Proxy to the list of proxies the Client will use.

Note

Adding a proxy will disable the automatic usage of the “system” proxy.

pub fn no_proxy(self) -> ClientBuilder

Clear all Proxies, so Client will use no proxy anymore.

This also disables the automatic usage of the “system” proxy.

pub fn timeout<T>(self, timeout: T) -> ClientBuilder where
    T: Into<Option<Duration>>, 

Set a timeout for connect, read and write operations of a Client.

Default is 30 seconds.

Pass None to disable timeout.

pub fn connect_timeout<T>(self, timeout: T) -> ClientBuilder where
    T: Into<Option<Duration>>, 

Set a timeout for only the connect phase of a Client.

Default is None.

pub fn connection_verbose(self, verbose: bool) -> ClientBuilder

Set whether connections should emit verbose logs.

Enabling this option will emit log messages at the TRACE level for read and write operations on connections.

pub fn pool_idle_timeout<D>(self, val: D) -> ClientBuilder where
    D: Into<Option<Duration>>, 

Set an optional timeout for idle sockets being kept-alive.

Pass None to disable timeout.

Default is 90 seconds.

pub fn pool_max_idle_per_host(self, max: usize) -> ClientBuilder

Sets the maximum idle connection per host allowed in the pool.

pub fn http1_title_case_headers(self) -> ClientBuilder

Enable case sensitive headers.

pub fn http2_prior_knowledge(self) -> ClientBuilder

Only use HTTP/2.

pub fn http2_initial_stream_window_size(
    self,
    sz: impl Into<Option<u32>>
) -> ClientBuilder

Sets the SETTINGS_INITIAL_WINDOW_SIZE option for HTTP2 stream-level flow control.

Default is currently 65,535 but may change internally to optimize for common uses.

pub fn http2_initial_connection_window_size(
    self,
    sz: impl Into<Option<u32>>
) -> ClientBuilder

Sets the max connection-level flow control for HTTP2

Default is currently 65,535 but may change internally to optimize for common uses.

pub fn http2_adaptive_window(self, enabled: bool) -> ClientBuilder

Sets whether to use an adaptive flow control.

Enabling this will override the limits set in http2_initial_stream_window_size and http2_initial_connection_window_size.

pub fn http2_max_frame_size(self, sz: impl Into<Option<u32>>) -> ClientBuilder

Sets the maximum frame size to use for HTTP2.

Default is currently 16,384 but may change internally to optimize for common uses.

pub fn tcp_nodelay(self, enabled: bool) -> ClientBuilder

Set whether sockets have SO_NODELAY enabled.

Default is true.

pub fn local_address<T>(self, addr: T) -> ClientBuilder where
    T: Into<Option<IpAddr>>, 

Bind to a local IP Address.

Example

use std::net::IpAddr;
let local_addr = IpAddr::from([12, 4, 1, 8]);
let client = reqwest::blocking::Client::builder()
    .local_address(local_addr)
    .build().unwrap();

pub fn tcp_keepalive<D>(self, val: D) -> ClientBuilder where
    D: Into<Option<Duration>>, 

Set that all sockets have SO_KEEPALIVE set with the supplied duration.

If None, the option will not be set.

pub fn add_root_certificate(self, cert: Certificate) -> ClientBuilder

Add a custom root certificate.

This allows connecting to a server that has a self-signed certificate for example. This does not replace the existing trusted store.

Example

// read a local binary DER encoded certificate
let der = std::fs::read("my-cert.der")?;

// create a certificate
let cert = reqwest::Certificate::from_der(&der)?;

// get a client builder
let client = reqwest::blocking::Client::builder()
    .add_root_certificate(cert)
    .build()?;

Optional

This requires the optional default-tls, native-tls, or rustls-tls(-...) feature to be enabled.

pub fn tls_built_in_root_certs(
    self,
    tls_built_in_root_certs: bool
) -> ClientBuilder

Controls the use of built-in system certificates during certificate validation.

Defaults to true – built-in system certs will be used.

Optional

This requires the optional default-tls, native-tls, or rustls-tls(-...) feature to be enabled.

pub fn identity(self, identity: Identity) -> ClientBuilder

Sets the identity to be used for client certificate authentication.

Optional

This requires the optional native-tls or rustls-tls(-...) feature to be enabled.

pub fn danger_accept_invalid_certs(
    self,
    accept_invalid_certs: bool
) -> ClientBuilder

Controls the use of certificate validation.

Defaults to false.

Warning

You should think very carefully before using this method. If invalid certificates are trusted, any certificate for any site will be trusted for use. This includes expired certificates. This introduces significant vulnerabilities, and should only be used as a last resort.

pub fn use_rustls_tls(self) -> ClientBuilder

Force using the Rustls TLS backend.

Since multiple TLS backends can be optionally enabled, this option will force the rustls backend to be used for this Client.

Optional

This requires the optional rustls-tls(-...) feature to be enabled.

pub fn use_preconfigured_tls(self, tls: impl Any) -> ClientBuilder

Use a preconfigured TLS backend.

If the passed Any argument is not a TLS backend that reqwest understands, the ClientBuilder will error when calling build.

Advanced

This is an advanced option, and can be somewhat brittle. Usage requires keeping the preconfigured TLS argument version in sync with reqwest, since version mismatches will result in an “unknown” TLS backend.

If possible, it’s preferable to use the methods on ClientBuilder to configure reqwest’s TLS.

Optional

This requires one of the optional features native-tls or rustls-tls(-...) to be enabled.

pub fn no_trust_dns(self) -> ClientBuilder

Disables the trust-dns async resolver.

This method exists even if the optional trust-dns feature is not enabled. This can be used to ensure a Client doesn’t use the trust-dns async resolver even if another dependency were to enable the optional trust-dns feature.

pub fn https_only(self, enabled: bool) -> ClientBuilder

Restrict the Client to be used with HTTPS only requests.

Defaults to false.

Trait Implementations

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.

impl From<ClientBuilder> for ClientBuilder

fn from(builder: ClientBuilder) -> Self

Performs the conversion.