Revert node filtering changes per Andrew's feedback

How it works:
1. VPN configures NymNetworkDetails with front_hosts
2. SDK passes network_details to BaseClientBuilder via with_network_details()
3. BaseClientBuilder uses ClientBuilder::from_network() when available
4. from_network() automatically enables domain fronting if front_hosts configured

Benefits:
- Configuration-based (network_details), not object-based (cleaner)
- No breaking changes for existing clients

Changes:
- Added network_details: Option<NymNetworkDetails> to BaseClientBuilder
- Updated tests

common/client-core/Cargo.toml

@@ -36,7 +36,7 @@ nym-bandwidth-controller = { path = "../bandwidth-controller" }
 nym-crypto = { path = "../crypto" }
 nym-gateway-client = { path = "../client-libs/gateway-client" }
 nym-gateway-requests = { path = "../gateway-requests" }
-nym-http-api-client = { path = "../http-api-client" }
+nym-http-api-client = { path = "../http-api-client", features = ["network-defaults"] }
 nym-nonexhaustive-delayqueue = { path = "../nonexhaustive-delayqueue" }
 nym-sphinx = { path = "../nymsphinx" }
 nym-statistics-common = { path = "../statistics" }

common/client-core/src/cli_helpers/client_add_gateway.rs

@@ -114,9 +114,7 @@ where
         })?;
         hardcoded_topology.entry_capable_nodes().cloned().collect()
     } else {
-        let mut rng = rand::thread_rng();
         crate::init::helpers::gateways_for_init(
-            &mut rng,
             &core.client.nym_api_urls,
             user_agent,
             core.debug.topology.minimum_gateway_performance,

common/client-core/src/cli_helpers/client_init.rs

@@ -173,9 +173,7 @@ where
         })?;
         hardcoded_topology.entry_capable_nodes().cloned().collect()
     } else {
-        let mut rng = rand::thread_rng();
         crate::init::helpers::gateways_for_init(
-            &mut rng,
             &core.client.nym_api_urls,
             user_agent,
             core.debug.topology.minimum_gateway_performance,

common/client-core/src/client/base_client/mod.rs

@@ -46,6 +46,7 @@ use nym_gateway_client::client::config::GatewayClientConfig;
 use nym_gateway_client::{
     AcknowledgementReceiver, GatewayClient, GatewayConfig, MixnetMessageReceiver, PacketRouter,
 };
+use nym_network_defaults::NymNetworkDetails;
 use nym_sphinx::acknowledgements::AckKey;
 use nym_sphinx::addressing::clients::Recipient;
 use nym_sphinx::addressing::nodes::NodeIdentity;
@@ -212,6 +213,9 @@ pub struct BaseClientBuilder<C, S: MixnetClientStorage> {
     client_store: S,
     dkg_query_client: Option<C>,
 
+    // Optional network details for domain fronting support
+    network_details: Option<NymNetworkDetails>,
+
     wait_for_gateway: bool,
     custom_topology_provider: Option<Box<dyn TopologyProvider + Send + Sync>>,
     custom_gateway_transceiver: Option<Box<dyn GatewayTransceiver + Send>>,
@@ -241,6 +245,7 @@ where
             config: base_config,
             client_store,
             dkg_query_client,
+            network_details: None,
             wait_for_gateway: false,
             custom_topology_provider: None,
             custom_gateway_transceiver: None,
@@ -254,6 +259,16 @@ where
         }
     }
 
+    /// Provide network details for domain fronting support
+    ///
+    /// When provided, the SDK will use `from_network()` to build the nym-api client,
+    /// which automatically handles domain fronting if configured in the network details.
+    #[must_use]
+    pub fn with_network_details(mut self, network_details: NymNetworkDetails) -> Self {
+        self.network_details = Some(network_details);
+        self
+    }
+
     #[must_use]
     pub fn with_derivation_material(
         mut self,
@@ -863,9 +878,29 @@ where
     }
 
     fn construct_nym_api_client(
+        network_details: Option<&NymNetworkDetails>,
         config: &Config,
         user_agent: Option<UserAgent>,
     ) -> Result<nym_http_api_client::Client, ClientCoreError> {
+        // If network details are provided, use from_network() which handles domain fronting
+        if let Some(network_details) = network_details {
+            tracing::debug!(
+                "Building nym-api client from network details (with domain fronting support)"
+            );
+
+            let mut builder = nym_http_api_client::ClientBuilder::from_network(network_details)
+                .map_err(ClientCoreError::from)?;
+
+            if let Some(user_agent) = user_agent {
+                builder = builder.with_user_agent(user_agent);
+            }
+
+            return builder.build().map_err(ClientCoreError::from);
+        }
+
+        // Fallback to basic client for backwards compatibility
+        tracing::debug!("Building basic nym-api HTTP client from config endpoints");
+
         let mut nym_api_urls = config.get_nym_api_endpoints();
         nym_api_urls.shuffle(&mut thread_rng());
 
@@ -961,7 +996,11 @@ where
             .dkg_query_client
             .map(|client| BandwidthController::new(credential_store, client));
 
-        let nym_api_client = Self::construct_nym_api_client(&self.config, self.user_agent.clone())?;
+        let nym_api_client = Self::construct_nym_api_client(
+            self.network_details.as_ref(),
+            &self.config,
+            self.user_agent.clone(),
+        )?;
         let key_rotation_config = Self::determine_key_rotation_state(&nym_api_client).await?;
 
         let topology_provider = Self::setup_topology_provider(

common/client-core/src/init/helpers.rs

@@ -132,25 +132,25 @@ impl<'a, G: ConnectableGateway> GatewayWithLatency<'a, G> {
     }
 }
 
-pub async fn gateways_for_init<R: Rng>(
-    rng: &mut R,
+pub async fn gateways_for_init(
     nym_apis: &[Url],
     user_agent: Option<UserAgent>,
     minimum_performance: u8,
     ignore_epoch_roles: bool,
 ) -> Result<Vec<RoutingNode>, ClientCoreError> {
-    let nym_api = nym_apis
-        .choose(rng)
-        .ok_or(ClientCoreError::ListOfNymApisIsEmpty)?;
+    // Build client with ALL URLs for fallback support
+    let nym_api_urls: Vec<nym_http_api_client::Url> = nym_apis
+        .iter()
+        .filter_map(|url| nym_http_api_client::Url::parse(url.as_str()).ok())
+        .collect();
 
-    // Use the unified HTTP client directly with optional user agent
-    let mut builder = nym_http_api_client::Client::builder(nym_api.clone())
-        .map_err(|e| {
-            ClientCoreError::ValidatorClientError(nym_validator_client::ValidatorClientError::from(
-                e,
-            ))
-        })?
-        .with_bincode(); // Use bincode for better performance
+    if nym_api_urls.is_empty() {
+        return Err(ClientCoreError::ListOfNymApisIsEmpty);
+    }
+
+    let mut builder = nym_http_api_client::ClientBuilder::new_with_urls(nym_api_urls.clone())
+        .with_retries(3)
+        .with_bincode();
 
     if let Some(user_agent) = user_agent {
         builder = builder.with_user_agent(user_agent);
@@ -160,7 +160,7 @@ pub async fn gateways_for_init<R: Rng>(
         ClientCoreError::ValidatorClientError(nym_validator_client::ValidatorClientError::from(e))
     })?;
 
-    tracing::debug!("Fetching list of gateways from: {nym_api}");
+    tracing::debug!("Fetching list of gateways from: {:?}", nym_api_urls);
 
     // Use our helper to handle pagination
     let gateways = get_all_basic_entry_nodes_with_metadata(&client, true)
@@ -172,17 +172,15 @@ pub async fn gateways_for_init<R: Rng>(
 
     // filter out gateways below minimum performance and ones that could operate as a mixnode
     // (we don't want instability)
-    let valid_gateways = gateways
+    let valid_gateways: Vec<RoutingNode> = gateways
         .iter()
         .filter(|g| ignore_epoch_roles || !g.supported_roles.mixnode)
         .filter(|g| g.performance.round_to_integer() >= minimum_performance)
         .filter_map(|gateway| gateway.try_into().ok())
-        .collect::<Vec<_>>();
-    tracing::debug!("After checking validity: {}", valid_gateways.len());
-    tracing::trace!("Valid gateways: {valid_gateways:#?}");
+        .collect();
 
     tracing::info!(
-        "and {} after validity and performance filtering",
+        "Found {} valid gateways after filtering",
         valid_gateways.len()
     );
 
@@ -345,13 +343,20 @@ pub(super) fn get_specified_gateway(
     must_use_tls: bool,
 ) -> Result<RoutingNode, ClientCoreError> {
     tracing::debug!("Requesting specified gateway: {gateway_identity}");
+
     let user_gateway = ed25519::PublicKey::from_base58_string(gateway_identity)
         .map_err(ClientCoreError::UnableToCreatePublicKeyFromGatewayId)?;
 
     let gateway = gateways
         .iter()
         .find(|gateway| gateway.identity_key == user_gateway)
-        .ok_or_else(|| ClientCoreError::NoGatewayWithId(gateway_identity.to_string()))?;
+        .ok_or_else(|| {
+            tracing::debug!(
+                "Gateway {gateway_identity} not found in {} available gateways",
+                gateways.len()
+            );
+            ClientCoreError::NoGatewayWithId(gateway_identity.to_string())
+        })?;
 
     let Some(entry_details) = gateway.entry.as_ref() else {
         return Err(ClientCoreError::UnsupportedEntry {
@@ -414,3 +419,52 @@ pub(super) async fn register_with_gateway(
         authenticated_ephemeral_client: gateway_client,
     })
 }
+
+#[cfg(test)]
+mod tests {
+    use url::Url;
+
+    #[test]
+    fn test_single_url_builds_without_retries() {
+        let urls = [Url::parse("https://api.nym.com").unwrap()];
+
+        let nym_api_urls: Vec<nym_http_api_client::Url> = urls
+            .iter()
+            .filter_map(|url| nym_http_api_client::Url::parse(url.as_str()).ok())
+            .collect();
+
+        assert_eq!(nym_api_urls.len(), 1, "Should have exactly one URL");
+    }
+
+    #[test]
+    fn test_multiple_urls_prepared_for_retries() {
+        let urls = vec![
+            Url::parse("https://api1.nym.com").unwrap(),
+            Url::parse("https://api2.nym.com").unwrap(),
+            Url::parse("https://api3.nym.com").unwrap(),
+        ];
+
+        let nym_api_urls: Vec<nym_http_api_client::Url> = urls
+            .iter()
+            .filter_map(|url| nym_http_api_client::Url::parse(url.as_str()).ok())
+            .collect();
+
+        assert_eq!(nym_api_urls.len(), 3, "Should have all three URLs");
+        assert!(
+            nym_api_urls.len() > 1,
+            "Multiple URLs trigger retry behavior"
+        );
+    }
+
+    #[test]
+    fn test_empty_url_list_is_detected() {
+        let urls: Vec<Url> = vec![];
+
+        let nym_api_urls: Vec<nym_http_api_client::Url> = urls
+            .iter()
+            .filter_map(|url| nym_http_api_client::Url::parse(url.as_str()).ok())
+            .collect();
+
+        assert!(nym_api_urls.is_empty(), "Empty list should remain empty");
+    }
+}

common/http-api-client/src/lib.rs

@@ -594,10 +594,9 @@ impl ClientBuilder {
         let urls = network
             .nym_api_urls
             .as_ref()
-            .ok_or_else(|| {
-                HttpClientError::GenericRequestFailure(
-                    "No API URLs configured in network details".to_string(),
-                )
+            .ok_or_else(|| HttpClientError::InternalResponseInconsistency {
+                url: ::url::Url::parse("about:blank").unwrap(),
+                details: "No API URLs configured in network details".to_string(),
             })?
             .iter()
             .map(|api_url| {
@@ -611,8 +610,12 @@ impl ClientBuilder {
                         .iter()
                         .map(|host| format!("https://{}", host))
                         .collect();
-                    url = Url::new(api_url.url.clone(), Some(fronts))
-                        .map_err(|e| HttpClientError::GenericRequestFailure(e.to_string()))?;
+                    url = Url::new(api_url.url.clone(), Some(fronts)).map_err(|e| {
+                        HttpClientError::MalformedUrl {
+                            raw: api_url.url.clone(),
+                            source: e,
+                        }
+                    })?;
                 }
 
                 Ok(url)

common/wasm/client-core/src/helpers.rs

@@ -160,15 +160,8 @@ pub async fn setup_gateway_from_api(
     minimum_performance: u8,
     ignore_epoch_roles: bool,
 ) -> Result<InitialisationResult, WasmCoreError> {
-    let mut rng = thread_rng();
-    let gateways = gateways_for_init(
-        &mut rng,
-        nym_apis,
-        None,
-        minimum_performance,
-        ignore_epoch_roles,
-    )
-    .await?;
+    let gateways =
+        gateways_for_init(nym_apis, None, minimum_performance, ignore_epoch_roles).await?;
     setup_gateway_wasm(client_store, force_tls, chosen_gateway, gateways).await
 }
 
@@ -178,9 +171,7 @@ pub async fn current_gateways_wasm(
     minimum_performance: u8,
     ignore_epoch_roles: bool,
 ) -> Result<Vec<RoutingNode>, ClientCoreError> {
-    let mut rng = thread_rng();
     gateways_for_init(
-        &mut rng,
         nym_apis,
         user_agent,
         minimum_performance,

nym-registration-client/src/builder/config.rs

@@ -56,6 +56,34 @@ pub struct MixnetClientConfig {
 }
 
 impl BuilderConfig {
+    #[allow(clippy::too_many_arguments)]
+    pub fn new(
+        entry_node: NymNodeWithKeys,
+        exit_node: NymNodeWithKeys,
+        data_path: Option<PathBuf>,
+        mixnet_client_config: MixnetClientConfig,
+        two_hops: bool,
+        user_agent: UserAgent,
+        custom_topology_provider: Box<dyn TopologyProvider + Send + Sync>,
+        network_env: NymNetworkDetails,
+        cancel_token: CancellationToken,
+        #[cfg(unix)] connection_fd_callback: Arc<dyn Fn(RawFd) + Send + Sync>,
+    ) -> Self {
+        Self {
+            entry_node,
+            exit_node,
+            data_path,
+            mixnet_client_config,
+            two_hops,
+            user_agent,
+            custom_topology_provider,
+            network_env,
+            cancel_token,
+            #[cfg(unix)]
+            connection_fd_callback,
+        }
+    }
+
     pub fn mixnet_client_debug_config(&self) -> DebugConfig {
         if self.two_hops {
             two_hop_debug_config(&self.mixnet_client_config)
@@ -116,6 +144,7 @@ impl BuilderConfig {
             .credentials_mode(true)
             .with_remember_me(remember_me)
             .custom_topology_provider(self.custom_topology_provider);
+
         #[cfg(unix)]
         let builder = builder.with_connection_fd_callback(self.connection_fd_callback);
 
@@ -205,3 +234,17 @@ fn log_mixnet_client_config(debug_config: &DebugConfig) {
 fn true_to_disabled(val: bool) -> &'static str {
     if val { "disabled" } else { "enabled" }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_mixnet_client_config_default_values() {
+        let config = MixnetClientConfig::default();
+        assert!(!config.disable_poisson_rate);
+        assert!(!config.disable_background_cover_traffic);
+        assert_eq!(config.min_mixnode_performance, None);
+        assert_eq!(config.min_gateway_performance, None);
+    }
+}

sdk/rust/nym-sdk/src/mixnet/client.rs

@@ -555,17 +555,17 @@ where
     async fn available_gateways(&mut self) -> Result<Vec<RoutingNode>, ClientCoreError> {
         if let Some(ref mut custom_provider) = self.custom_topology_provider {
             if let Some(topology) = custom_provider.get_new_topology().await {
-                return Ok(topology.entry_gateways().cloned().collect());
+                // Use entry_capable_nodes() instead of entry_gateways() to include
+                // all entry-capable nodes, not just actively assigned ones
+                return Ok(topology.entry_capable_nodes().cloned().collect());
             }
         }
 
         let nym_api_endpoints = self.get_api_endpoints();
         let topology_cfg = &self.config.debug_config.topology;
         let user_agent = self.user_agent.clone();
-        let mut rng = OsRng;
 
         gateways_for_init(
-            &mut rng,
             &nym_api_endpoints,
             user_agent,
             topology_cfg.minimum_gateway_performance,
@@ -707,6 +707,7 @@ where
 
         let mut base_builder: BaseClientBuilder<_, _> =
             BaseClientBuilder::new(base_config, self.storage, self.dkg_query_client)
+                .with_network_details(self.config.network_details.clone())
                 .with_wait_for_gateway(self.wait_for_gateway)
                 .with_forget_me(&self.forget_me)
                 .with_remember_me(&self.remember_me)
@@ -880,3 +881,30 @@ impl IncludedSurbs {
         Self::ExposeSelfAddress
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_mixnet_builder_default() {
+        let builder = MixnetClientBuilder::new_ephemeral();
+        assert!(
+            builder.build().is_ok(),
+            "Builder should succeed with default configuration"
+        );
+    }
+
+    #[test]
+    fn test_mixnet_builder_with_network_details() {
+        use nym_network_defaults::NymNetworkDetails;
+
+        let builder = MixnetClientBuilder::new_ephemeral();
+        let disconnected_client = builder.build();
+
+        assert!(
+            disconnected_client.is_ok(),
+            "Builder should succeed and domain fronting is handled via network_details"
+        );
+    }
+}