diff --git a/CHANGELOG.md b/CHANGELOG.md
index 031f71c..a1f9540 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,13 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
+### [0.0.1-alpha.41](https://github.com/DIG-Network/dig-propagation-server/compare/v0.0.1-alpha.40...v0.0.1-alpha.41) (2024-09-22)
+
+
+### Features
+
+* upload dat file as part up upload session ([4b97d08](https://github.com/DIG-Network/dig-propagation-server/commit/4b97d08296c39d337221b8f73d50149b618ffa2f))
+
 ### [0.0.1-alpha.40](https://github.com/DIG-Network/dig-propagation-server/compare/v0.0.1-alpha.39...v0.0.1-alpha.40) (2024-09-22)
 
 
diff --git a/package-lock.json b/package-lock.json
index dcd0aa9..ef7e409 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "dig-propagation-server",
-  "version": "0.0.1-alpha.40",
+  "version": "0.0.1-alpha.41",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "dig-propagation-server",
-      "version": "0.0.1-alpha.40",
+      "version": "0.0.1-alpha.41",
       "license": "ISC",
       "dependencies": {
         "@dignetwork/dig-sdk": "^0.0.1-alpha.57",
diff --git a/package.json b/package.json
index 513faf6..f96aeff 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "dig-propagation-server",
-  "version": "0.0.1-alpha.40",
+  "version": "0.0.1-alpha.41",
   "description": "",
   "type": "commonjs",
   "main": "./dist/index.js",
diff --git a/src/controllers/merkleTreeController.ts b/src/controllers/merkleTreeController.ts
index 8fd9907..6272077 100644
--- a/src/controllers/merkleTreeController.ts
+++ b/src/controllers/merkleTreeController.ts
@@ -212,24 +212,17 @@ export const startUploadSession = async (
       session.resetTtl(); // Reset TTL on each chunk of data
     });
 
-    // Extract the file and its metadata from the FormData body
-    const contentDisposition = req.headers["content-disposition"] || "";
-    const matches = contentDisposition.match(/filename="(.+?)"/);
-    if (!matches) {
-      throw new HttpError(400, "Missing filename in the upload request.");
-    }
-    
-    const filename = matches[1];
-    if (!/^[a-fA-F0-9]{64}\.dat$/.test(filename)) {
-      throw new HttpError(400, "Invalid rootHash format in the filename.");
+    const rootHash = req.query.roothash as string;
+    if (!rootHash || !/^[a-fA-F0-9]{64}$/.test(rootHash)) {
+      throw new HttpError(400, "Invalid or missing rootHash.");
     }
 
-    const rootHash = filename.split(".")[0]; // Extract rootHash from the file name
-    const tmpDatFilePath = path.join(session.tmpDir, filename);
+    // Create the file path for saving the uploaded .dat file
+    const tmpDatFilePath = path.join(session.tmpDir, `${rootHash}.dat`);
+    const fileStream = fs.createWriteStream(tmpDatFilePath);
 
     // Stream the file from the request body into the temp file
-    const fileWriteStream = fs.createWriteStream(tmpDatFilePath);
-    await streamPipeline(req.pipe(passThrough), fileWriteStream);
+    await streamPipeline(req.pipe(passThrough), fileStream);
 
     // Now validate the file once it's saved
     await validateDataFile(tmpDatFilePath, storeId);
@@ -317,6 +310,7 @@ export const uploadFile = async (
     }
 
     // Validate the key ownership signature using the nonce
+
     const isSignatureValid = await Wallet.verifyKeyOwnershipSignature(
       nonce,
       keyOwnershipSig,