diff --git a/node/rpc/src/zgs/api.rs b/node/rpc/src/zgs/api.rs
index abc33ea..a3b0ac1 100644
--- a/node/rpc/src/zgs/api.rs
+++ b/node/rpc/src/zgs/api.rs
@@ -87,4 +87,7 @@ pub trait Rpc {
 
     #[method(name = "getFlowContext")]
     async fn get_flow_context(&self) -> RpcResult<(H256, u64)>;
+
+    #[method(name = "getChunkByIndex")]
+    async fn get_chunk_by_index(&self, chunk_index: u64) -> RpcResult<Option<Vec<u8>>>;
 }
diff --git a/node/rpc/src/zgs/impl.rs b/node/rpc/src/zgs/impl.rs
index cffc7fa..60b5eab 100644
--- a/node/rpc/src/zgs/impl.rs
+++ b/node/rpc/src/zgs/impl.rs
@@ -238,6 +238,25 @@ impl RpcServer for RpcServerImpl {
     async fn get_flow_context(&self) -> RpcResult<(H256, u64)> {
         Ok(self.ctx.log_store.get_context().await?)
     }
+
+    async fn get_chunk_by_index(&self, chunk_index: u64) -> RpcResult<Option<Vec<u8>>> {
+        debug!(%chunk_index, "zgs_getChunkByIndex");
+        match self
+            .ctx
+            .log_store
+            .get_chunk_by_flow_index(chunk_index, 1)
+            .await?
+        {
+            Some(chunk_array) => {
+                if chunk_array.data.len() > 0 {
+                    Ok(Some(chunk_array.data))
+                } else {
+                    Ok(None)
+                }
+            }
+            None => Ok(None),
+        }
+    }
 }
 
 impl RpcServerImpl {
diff --git a/node/storage/src/log_store/flow_store.rs b/node/storage/src/log_store/flow_store.rs
index 94d7863..cb1b248 100644
--- a/node/storage/src/log_store/flow_store.rs
+++ b/node/storage/src/log_store/flow_store.rs
@@ -236,7 +236,7 @@ impl FlowWrite for FlowStore {
 
         debug!(
             "Entry batch data at 12288 before insert: {:?}",
-            batch_data_12288.as_ssz_bytes()
+            batch_data_12288
         );
 
         let mut batch_list = Vec::new();
@@ -293,7 +293,7 @@ impl FlowWrite for FlowStore {
 
         debug!(
             "Entry batch data at 12288 after insert: {:?}",
-            batch_data_12288.as_ssz_bytes()
+            batch_data_12288
         );
 
         res
diff --git a/node/storage/src/log_store/log_manager.rs b/node/storage/src/log_store/log_manager.rs
index c3bdc0f..02058b9 100644
--- a/node/storage/src/log_store/log_manager.rs
+++ b/node/storage/src/log_store/log_manager.rs
@@ -1125,6 +1125,7 @@ impl LogManager {
         let chunk_roots = self.flow_store.append_entries(flow_entry_array)?;
         debug!("fill leaf for pora_chunks_merkle");
         for (chunk_index, chunk_root) in chunk_roots {
+            debug!("fill leaf: chunk_index={}, chunk_root={:?}", chunk_index, chunk_root);
             if chunk_index < merkle.pora_chunks_merkle.leaves() as u64 {
                 merkle
                     .pora_chunks_merkle