diff --git a/taxonium_data_handling/importing.js b/taxonium_data_handling/importing.js
index acbf08b2..d01c8dfd 100644
--- a/taxonium_data_handling/importing.js
+++ b/taxonium_data_handling/importing.js
@@ -1,6 +1,40 @@
 import zlib from "zlib";
 import stream from "stream";
 import buffer from "buffer";
+import { send } from "process";
+
+
+class ChunkCounterStream extends stream.PassThrough {
+  constructor(sendStatusMessage, options = {}) {
+    super(options);
+    this.sendStatusMessage = sendStatusMessage;
+    this.chunkCount = 0;
+  }
+
+  _transform(chunk, encoding, callback) {
+    this.chunkCount++;
+    if (this.chunkCount % 100 === 0) {
+    this.sendStatusMessage({
+      message: `Processed ${this.chunkCount} groups of mutations`,
+      count: this.chunkCount
+    });
+  }
+    
+    // Pass the chunk through unchanged
+    this.push(chunk);
+    callback();
+  }
+
+  _flush(callback) {
+    this.sendStatusMessage({
+      message: `Finished processing. Total chunks: ${this.chunkCount}`,
+      count: this.chunkCount,
+      finished: true
+    });
+    callback();
+  }
+}
+
 
 class StreamSplitter extends stream.Transform {
   constructor(headerParser, dataParser, options = {}) {
@@ -153,9 +187,9 @@ export const setUpStream = (
     data.node_to_mut[decoded.node_id] = decoded.mutations;
     data.nodes.push(decoded);
   }
-
-  // Set up the splitter with headerParser and dataParser
-  const splitter = new StreamSplitter(headerParser, dataParser);
+  const chunkCounterStream = new ChunkCounterStream(sendStatusMessage);
+  chunkCounterStream.pipe(headerParser);
+  const splitter = new StreamSplitter(chunkCounterStream, dataParser);
 
   // Pipe the input stream through the splitter
   the_stream.pipe(splitter).on("error", (err) => console.error("Splitter error:", err));