diff --git a/sdk-libs/client/src/indexer/error.rs b/sdk-libs/client/src/indexer/error.rs
index 5e83fe2d08..2a5ca31e94 100644
--- a/sdk-libs/client/src/indexer/error.rs
+++ b/sdk-libs/client/src/indexer/error.rs
@@ -46,7 +46,9 @@ pub enum IndexerError {
 
     #[error("Error: `{0}`")]
     CustomError(String),
-    #[error("Indexer not initialized.")]
+    #[error(
+        "Indexer not initialized. Set photon_url in LightClientConfig to enable indexer API calls."
+    )]
     NotInitialized,
     #[error("Indexer slot has not reached the requested slot.")]
     IndexerNotSyncedToSlot,
@@ -91,7 +93,7 @@ impl<T> From<photon_api::apis::Error<T>> for IndexerError {
                 IndexerError::ApiError(format!("Serialization error: {}", e))
             }
             photon_api::apis::Error::Io(e) => IndexerError::ApiError(format!("IO error: {}", e)),
-            _ => IndexerError::ApiError("Unknown API error".to_string()),
+            _ => IndexerError::ApiError(format!("Unknown API error {}", error)),
         }
     }
 }
diff --git a/sdk-libs/client/src/indexer/photon_indexer.rs b/sdk-libs/client/src/indexer/photon_indexer.rs
index 0370cf392d..c3129aaba5 100644
--- a/sdk-libs/client/src/indexer/photon_indexer.rs
+++ b/sdk-libs/client/src/indexer/photon_indexer.rs
@@ -132,9 +132,7 @@ impl PhotonIndexer {
         result: Option<T>,
     ) -> Result<T, IndexerError> {
         if let Some(error) = error {
-            let error_message = error
-                .message
-                .unwrap_or_else(|| "Unknown API error".to_string());
+            let error_message = error.message.unwrap_or_default();
             return Err(IndexerError::ApiError(format!(
                 "API error in {} (code: {:?}): {}",
                 context, error.code, error_message
diff --git a/sdk-libs/client/src/rpc/client.rs b/sdk-libs/client/src/rpc/client.rs
index 3102de4a72..494ee9a218 100644
--- a/sdk-libs/client/src/rpc/client.rs
+++ b/sdk-libs/client/src/rpc/client.rs
@@ -129,6 +129,24 @@ impl LightClient {
         self.indexer = Some(PhotonIndexer::new(path, api_key));
     }
 
+    /// Detects the network type based on the RPC URL
+    fn detect_network(&self) -> RpcUrl {
+        let url = self.client.url();
+
+        if url.contains("devnet") {
+            RpcUrl::Devnet
+        } else if url.contains("testnet") {
+            RpcUrl::Testnet
+        } else if url.contains("localhost") || url.contains("127.0.0.1") {
+            RpcUrl::Localnet
+        } else if url.contains("zk-testnet") {
+            RpcUrl::ZKTestnet
+        } else {
+            // Default to mainnet for production URLs and custom URLs
+            RpcUrl::Custom(url.to_string())
+        }
+    }
+
     async fn retry<F, Fut, T>(&self, operation: F) -> Result<T, RpcError>
     where
         F: Fn() -> Fut,
@@ -662,11 +680,48 @@ impl Rpc for LightClient {
 
     /// Fetch the latest state tree addresses from the cluster.
     async fn get_latest_active_state_trees(&mut self) -> Result<Vec<TreeInfo>, RpcError> {
-        let res = default_state_tree_lookup_tables().0;
+        let network = self.detect_network();
+
+        // Return default test values for localnet
+        if matches!(network, RpcUrl::Localnet) {
+            use light_compressed_account::TreeType;
+            use solana_pubkey::pubkey;
+
+            use crate::indexer::TreeInfo;
+
+            #[cfg(feature = "v2")]
+            let default_trees = vec![TreeInfo {
+                tree: pubkey!("HLKs5NJ8FXkJg8BrzJt56adFYYuwg5etzDtBbQYTsixu"),
+                queue: pubkey!("6L7SzhYB3anwEQ9cphpJ1U7Scwj57bx2xueReg7R9cKU"),
+                cpi_context: Some(pubkey!("7Hp52chxaew8bW1ApR4fck2bh6Y8qA1pu3qwH6N9zaLj")),
+                next_tree_info: None,
+                tree_type: TreeType::StateV2,
+            }];
+
+            #[cfg(not(feature = "v2"))]
+            let default_trees = vec![TreeInfo {
+                tree: pubkey!("smt1NamzXdq4AMqS2fS2F1i5KTYPZRhoHgWx38d8WsT"),
+                queue: pubkey!("nfq1NvQDJ2GEgnS8zt9prAe8rjjpAW1zFkrvZoBR148"),
+                cpi_context: Some(pubkey!("cpi1uHzrEhBG733DoEJNgHCyRS3XmmyVNZx5fonubE4")),
+                next_tree_info: None,
+                tree_type: TreeType::StateV1,
+            }];
+
+            self.state_merkle_trees = default_trees.clone();
+            return Ok(default_trees);
+        }
+
+        let (mainnet_tables, devnet_tables) = default_state_tree_lookup_tables();
+
+        let lookup_tables = match network {
+            RpcUrl::Devnet | RpcUrl::Testnet | RpcUrl::ZKTestnet => &devnet_tables,
+            _ => &mainnet_tables, // Default to mainnet for production and custom URLs
+        };
+
         let res = get_light_state_tree_infos(
             self,
-            &res[0].state_tree_lookup_table,
-            &res[0].nullify_table,
+            &lookup_tables[0].state_tree_lookup_table,
+            &lookup_tables[0].nullify_table,
         )
         .await?;
         self.state_merkle_trees = res.clone();