diff --git a/Cargo.lock b/Cargo.lock
index 3d2dc7ac..17142816 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -640,6 +640,7 @@ dependencies = [
  "http",
  "lazy_static",
  "os_type",
+ "parking_lot",
  "percent-encoding",
  "regex",
  "reqwest",
@@ -1332,6 +1333,16 @@ version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "23fb14cb19457329c82206317a5663005a4d404783dc74f4252769b0d5f42856"
 
+[[package]]
+name = "lock_api"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "07af8b9cdd281b7915f413fa73f29ebd5d55d0d3f0155584dade1ff18cea1b17"
+dependencies = [
+ "autocfg",
+ "scopeguard",
+]
+
 [[package]]
 name = "log"
 version = "0.4.27"
@@ -1512,6 +1523,29 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "parking_lot"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bf18183cf54e8d6059647fc3063646a1801cf30896933ec2311622cc4b9a27"
+dependencies = [
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.9.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e401f977ab385c9e4e3ab30627d6f26d00e2c73eef317493c4ec6d468726cf8"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "windows-targets 0.52.6",
+]
+
 [[package]]
 name = "path-slash"
 version = "0.2.1"
@@ -1894,6 +1928,12 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "scopeguard"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+
 [[package]]
 name = "security-framework"
 version = "2.11.1"
diff --git a/api_generator/Cargo.toml b/api_generator/Cargo.toml
index c7eecacd..5f7e1604 100644
--- a/api_generator/Cargo.toml
+++ b/api_generator/Cargo.toml
@@ -38,3 +38,6 @@ void = "1"
 
 [dev-dependencies]
 tempfile = "3.12"
+
+[lints.clippy]
+uninlined_format_args = "allow" # too pedantic
diff --git a/api_generator/src/generator/code_gen/request/request_builder.rs b/api_generator/src/generator/code_gen/request/request_builder.rs
index 56ae132d..3f8a1985 100644
--- a/api_generator/src/generator/code_gen/request/request_builder.rs
+++ b/api_generator/src/generator/code_gen/request/request_builder.rs
@@ -154,7 +154,7 @@ impl<'a> RequestBuilder<'a> {
                 }
             });
 
-            let query_ctor = endpoint_params.iter().map(|(param_name, _)| {
+            let query_ctor = endpoint_params.keys().map(|param_name| {
                 let field_name = ident(valid_name(param_name).to_lowercase());
                 quote! {
                     #field_name: self.#field_name
diff --git a/elasticsearch/Cargo.toml b/elasticsearch/Cargo.toml
index 73b8ba82..2d2ac706 100644
--- a/elasticsearch/Cargo.toml
+++ b/elasticsearch/Cargo.toml
@@ -26,6 +26,7 @@ native-tls = ["reqwest/native-tls"]
 rustls-tls = ["reqwest/rustls-tls"]
 
 [dependencies]
+parking_lot = "0.12"
 base64 = "0.22"
 bytes = "1"
 dyn-clone = "1"
@@ -61,3 +62,7 @@ xml-rs = "0.8"
 
 [build-dependencies]
 rustc_version = "0.4"
+
+[lints.clippy]
+needless_lifetimes = "allow" # generated lifetimes
+uninlined_format_args = "allow" # too pedantic
diff --git a/elasticsearch/src/http/transport.rs b/elasticsearch/src/http/transport.rs
index d44b9b71..74666657 100644
--- a/elasticsearch/src/http/transport.rs
+++ b/elasticsearch/src/http/transport.rs
@@ -54,10 +54,11 @@ use std::{
     io::{self, Write},
     sync::{
         atomic::{AtomicBool, AtomicUsize, Ordering},
-        Arc, RwLock,
+        Arc,
     },
     time::{Duration, Instant},
 };
+use parking_lot::RwLock;
 use url::Url;
 
 /// Error that can occur when building a [Transport]
@@ -68,6 +69,9 @@ pub enum BuildError {
 
     /// Certificate error
     Cert(reqwest::Error),
+
+    /// Configuration error
+    Config(String),
 }
 
 impl From<io::Error> for BuildError {
@@ -88,6 +92,7 @@ impl error::Error for BuildError {
         match *self {
             BuildError::Io(ref err) => err.description(),
             BuildError::Cert(ref err) => err.description(),
+            BuildError::Config(ref err) => err.as_str(),
         }
     }
 
@@ -95,6 +100,7 @@ impl error::Error for BuildError {
         match *self {
             BuildError::Io(ref err) => Some(err as &dyn error::Error),
             BuildError::Cert(ref err) => Some(err as &dyn error::Error),
+            BuildError::Config(_) => None,
         }
     }
 }
@@ -104,6 +110,7 @@ impl fmt::Display for BuildError {
         match *self {
             BuildError::Io(ref err) => fmt::Display::fmt(err, f),
             BuildError::Cert(ref err) => fmt::Display::fmt(err, f),
+            BuildError::Config(ref err) => fmt::Display::fmt(err, f),
         }
     }
 }
@@ -337,7 +344,7 @@ impl TransportBuilder {
             if let Some(c) = self.proxy_credentials {
                 proxy = match c {
                     Credentials::Basic(u, p) => proxy.basic_auth(&u, &p),
-                    _ => proxy,
+                    _ => return Err(BuildError::Config("Only Basic Authentication is supported for proxies".into())),
                 };
             }
             client_builder = client_builder.proxy(proxy);
@@ -348,7 +355,7 @@ impl TransportBuilder {
             client,
             conn_pool: self.conn_pool,
             request_body_compression: self.request_body_compression,
-            credentials: self.credentials,
+            credentials: Arc::new(RwLock::new(self.credentials)),
             send_meta: self.meta_header,
         })
     }
@@ -393,7 +400,7 @@ impl Connection {
 #[derive(Debug, Clone)]
 pub struct Transport {
     client: reqwest::Client,
-    credentials: Option<Credentials>,
+    credentials: Arc<RwLock<Option<Credentials>>>,
     request_body_compression: bool,
     conn_pool: Arc<dyn ConnectionPool>,
     send_meta: bool,
@@ -478,7 +485,7 @@ impl Transport {
     /// [Elasticsearch service in Elastic Cloud](https://www.elastic.co/cloud/).
     ///
     /// * `cloud_id`: The Elastic Cloud Id retrieved from the cloud web console, that uniquely
-    ///               identifies the deployment instance.
+    ///   identifies the deployment instance.
     /// * `credentials`: A set of credentials the client should use to authenticate to Elasticsearch service.
     pub fn cloud(cloud_id: &str, credentials: Credentials) -> Result<Transport, Error> {
         let conn_pool = CloudConnectionPool::new(cloud_id)?;
@@ -513,7 +520,8 @@ impl Transport {
         // set credentials before any headers, as credentials append to existing headers in reqwest,
         // whilst setting headers() overwrites, so if an Authorization header has been specified
         // on a specific request, we want it to overwrite.
-        if let Some(c) = &self.credentials {
+        let creds_guard = self.credentials.read();
+        if let Some(c) = creds_guard.as_ref() {
             request_builder = match c {
                 Credentials::Basic(u, p) => request_builder.basic_auth(u, Some(p)),
                 Credentials::Bearer(t) => request_builder.bearer_auth(t),
@@ -537,6 +545,7 @@ impl Transport {
                 }
             }
         }
+        drop(creds_guard);
 
         // default headers first, overwrite with any provided
         let mut request_headers = HeaderMap::with_capacity(4 + headers.len());
@@ -696,6 +705,12 @@ impl Transport {
             Err(e) => Err(e.into()),
         }
     }
+
+    /// Update the auth credentials for this transport and all its clones, and all clients
+    /// using them. Typically used to refresh a bearer token.
+    pub fn set_auth(&self, credentials: Credentials) {
+        *self.credentials.write() = Some(credentials);
+    }
 }
 
 impl Default for Transport {
@@ -895,14 +910,14 @@ where
     ConnSelector: ConnectionSelector + Clone,
 {
     fn next(&self) -> Connection {
-        let inner = self.inner.read().expect("lock poisoned");
+        let inner = self.inner.read();
         self.connection_selector
             .try_next(&inner.connections)
             .unwrap()
     }
 
     fn reseedable(&self) -> bool {
-        let inner = self.inner.read().expect("lock poisoned");
+        let inner = self.inner.read();
         let reseed_frequency = match self.reseed_frequency {
             Some(wait) => wait,
             None => return false,
@@ -928,10 +943,11 @@ where
     }
 
     fn reseed(&self, mut connection: Vec<Connection>) {
-        let mut inner = self.inner.write().expect("lock poisoned");
+        let mut inner = self.inner.write();
         inner.last_update = Some(Instant::now());
         inner.connections.clear();
         inner.connections.append(&mut connection);
+        drop(inner);
         self.reseeding.store(false, Ordering::Relaxed);
     }
 }
@@ -1210,7 +1226,7 @@ pub mod tests {
         );
 
         // Set internal last_update to a minute ago
-        let mut inner = connection_pool.inner.write().expect("lock poisoned");
+        let mut inner = connection_pool.inner.write();
         inner.last_update = Some(Instant::now() - Duration::from_secs(60));
         drop(inner);
 
@@ -1249,4 +1265,37 @@ pub mod tests {
         let connections = MultiNodeConnectionPool::round_robin(vec![], None);
         connections.next();
     }
+
+    #[test]
+    fn set_credentials() -> anyhow::Result<()> {
+        let t1: Transport = TransportBuilder::new(SingleNodeConnectionPool::default())
+            .auth(Credentials::Basic("foo".to_string(), "bar".to_string()))
+            .build()?;
+
+        if let Some(Credentials::Basic(login, password)) = t1.credentials.read().as_ref() {
+            assert_eq!(login, "foo");
+            assert_eq!(password, "bar");
+        } else {
+            panic!("Expected Basic credentials");
+        }
+
+        let t2 = t1.clone();
+
+        t1.set_auth(Credentials::Bearer("The bear".to_string()));
+
+        if let Some(Credentials::Bearer(token)) = t1.credentials.read().as_ref() {
+            assert_eq!(token, "The bear");
+        } else {
+            panic!("Expected Bearer credentials");
+        }
+
+        // Verify that cloned transport also has the same credentials
+        if let Some(Credentials::Bearer(token)) = t2.credentials.read().as_ref() {
+            assert_eq!(token, "The bear");
+        } else {
+            panic!("Expected Bearer credentials");
+        }
+
+        Ok(())
+    }
 }
diff --git a/elasticsearch/src/lib.rs b/elasticsearch/src/lib.rs
index 641e412c..b668b8c9 100644
--- a/elasticsearch/src/lib.rs
+++ b/elasticsearch/src/lib.rs
@@ -50,7 +50,7 @@
 //! - **native-tls** *(enabled by default)*: Enables TLS functionality provided by `native-tls`.
 //! - **rustls-tls**: Enables TLS functionality provided by `rustls`.
 //! - **beta-apis**: Enables beta APIs. Beta APIs are on track to become stable and permanent features. Use them with
-//!    caution because it is possible that breaking changes are made to these APIs in a minor version.
+//!   caution because it is possible that breaking changes are made to these APIs in a minor version.
 //! - **experimental-apis**: Enables experimental APIs. Experimental APIs are just that - an experiment. An experimental
 //!   API might have breaking changes in any future version, or it might even be removed entirely. This feature also
 //!   enables `beta-apis`.
diff --git a/xtask/Cargo.toml b/xtask/Cargo.toml
index d2efa7fc..b2658c39 100644
--- a/xtask/Cargo.toml
+++ b/xtask/Cargo.toml
@@ -15,3 +15,6 @@ chrono = { version = "0.4", features = ["serde"] }
 zip = "2"
 regex = "1"
 xshell = "0.2"
+
+[lints.clippy]
+uninlined_format_args = "allow" # too pedantic
diff --git a/yaml_test_runner/Cargo.toml b/yaml_test_runner/Cargo.toml
index a88b9567..a9635c67 100644
--- a/yaml_test_runner/Cargo.toml
+++ b/yaml_test_runner/Cargo.toml
@@ -42,3 +42,4 @@ tokio = { version = "1", default-features = false, features = ["macros", "net",
 [lints.clippy]
 # yaml tests contain approximate values of PI
 approx_constant = "allow"
+uninlined_format_args = "allow" # too pedantic
diff --git a/yaml_test_runner/src/generator.rs b/yaml_test_runner/src/generator.rs
index f09d469e..3369c808 100644
--- a/yaml_test_runner/src/generator.rs
+++ b/yaml_test_runner/src/generator.rs
@@ -425,7 +425,7 @@ pub fn generate_tests_from_yaml(
                     error!(
                         "skipping {}. cannot read as Yaml struct: {}",
                         relative_path.to_slash_lossy(),
-                        result.err().unwrap().to_string()
+                        result.err().unwrap()
                     );
                     continue;
                 }