diff --git a/Notesnook.API/Controllers/S3Controller.cs b/Notesnook.API/Controllers/S3Controller.cs
index 9db9762..6ba6c50 100644
--- a/Notesnook.API/Controllers/S3Controller.cs
+++ b/Notesnook.API/Controllers/S3Controller.cs
@@ -1,127 +1,128 @@
-/*
-This file is part of the Notesnook Sync Server project (https://notesnook.com/)
-
-Copyright (C) 2023 Streetwriters (Private) Limited
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the Affero GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-Affero GNU General Public License for more details.
-
-You should have received a copy of the Affero GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-using Microsoft.AspNetCore.Authorization;
-using Microsoft.AspNetCore.Mvc;
-using Amazon.S3.Model;
-using System.Threading.Tasks;
-using System.Security.Claims;
-using Notesnook.API.Interfaces;
-using System;
-
-namespace Notesnook.API.Controllers
-{
-    [ApiController]
-    [Route("s3")]
-    [ResponseCache(NoStore = true, Location = ResponseCacheLocation.None)]
-    public class S3Controller : ControllerBase
-    {
-        private IS3Service S3Service { get; set; }
-        public S3Controller(IS3Service s3Service)
-        {
-            S3Service = s3Service;
-        }
-
-        [HttpPut]
-        [Authorize("Pro")]
-        public IActionResult Upload([FromQuery] string name)
-        {
-            var userId = this.User.FindFirstValue("sub");
-            var url = S3Service.GetUploadObjectUrl(userId, name);
-            if (url == null) return BadRequest("Could not create signed url.");
-            return Ok(url);
-        }
-
-
-        [HttpGet("multipart")]
-        [Authorize("Pro")]
-        public async Task<IActionResult> MultipartUpload([FromQuery] string name, [FromQuery] int parts, [FromQuery] string uploadId)
-        {
-            var userId = this.User.FindFirstValue("sub");
-            try
-            {
-                var meta = await S3Service.StartMultipartUploadAsync(userId, name, parts, uploadId);
-                return Ok(meta);
-            }
-            catch (Exception ex) { return BadRequest(ex.Message); }
-        }
-
-        [HttpDelete("multipart")]
-        [Authorize("Pro")]
-        public async Task<IActionResult> AbortMultipartUpload([FromQuery] string name, [FromQuery] string uploadId)
-        {
-            var userId = this.User.FindFirstValue("sub");
-            try
-            {
-                await S3Service.AbortMultipartUploadAsync(userId, name, uploadId);
-                return Ok();
-            }
-            catch (Exception ex) { return BadRequest(ex.Message); }
-        }
-
-        [HttpPost("multipart")]
-        [Authorize("Pro")]
-        public async Task<IActionResult> CompleteMultipartUpload([FromBody] CompleteMultipartUploadRequest uploadRequest)
-        {
-            var userId = this.User.FindFirstValue("sub");
-            try
-            {
-                await S3Service.CompleteMultipartUploadAsync(userId, uploadRequest);
-                return Ok();
-            }
-            catch (Exception ex) { return BadRequest(ex.Message); }
-        }
-
-        [HttpGet]
-        [Authorize("Sync")]
-        public IActionResult Download([FromQuery] string name)
-        {
-            var userId = this.User.FindFirstValue("sub");
-            var url = S3Service.GetDownloadObjectUrl(userId, name);
-            if (url == null) return BadRequest("Could not create signed url.");
-            return Ok(url);
-        }
-
-        [HttpHead]
-        [Authorize("Sync")]
-        public async Task<IActionResult> Info([FromQuery] string name)
-        {
-            var userId = this.User.FindFirstValue("sub");
-            var size = await S3Service.GetObjectSizeAsync(userId, name);
-            HttpContext.Response.Headers.ContentLength = size;
-            return Ok();
-        }
-
-        [HttpDelete]
-        [Authorize("Sync")]
-        public async Task<IActionResult> DeleteAsync([FromQuery] string name)
-        {
-            try
-            {
-                var userId = this.User.FindFirstValue("sub");
-                await S3Service.DeleteObjectAsync(userId, name);
-                return Ok();
-            }
-            catch (Exception ex)
-            {
-                return BadRequest(ex.Message);
-            }
-        }
-    }
-}
+/*
+This file is part of the Notesnook Sync Server project (https://notesnook.com/)
+
+Copyright (C) 2023 Streetwriters (Private) Limited
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the Affero GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+Affero GNU General Public License for more details.
+
+You should have received a copy of the Affero GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Amazon.S3.Model;
+using System.Threading.Tasks;
+using System.Security.Claims;
+using Notesnook.API.Interfaces;
+using System;
+using Notesnook.API.Models;
+
+namespace Notesnook.API.Controllers
+{
+    [ApiController]
+    [Route("s3")]
+    [ResponseCache(NoStore = true, Location = ResponseCacheLocation.None)]
+    public class S3Controller : ControllerBase
+    {
+        private IS3Service S3Service { get; set; }
+        public S3Controller(IS3Service s3Service)
+        {
+            S3Service = s3Service;
+        }
+
+        [HttpPut]
+        [Authorize("Pro")]
+        public IActionResult Upload([FromQuery] string name)
+        {
+            var userId = this.User.FindFirstValue("sub");
+            var url = S3Service.GetUploadObjectUrl(userId, name);
+            if (url == null) return BadRequest("Could not create signed url.");
+            return Ok(url);
+        }
+
+
+        [HttpGet("multipart")]
+        [Authorize("Pro")]
+        public async Task<IActionResult> MultipartUpload([FromQuery] string name, [FromQuery] int parts, [FromQuery] string uploadId)
+        {
+            var userId = this.User.FindFirstValue("sub");
+            try
+            {
+                var meta = await S3Service.StartMultipartUploadAsync(userId, name, parts, uploadId);
+                return Ok(meta);
+            }
+            catch (Exception ex) { return BadRequest(ex.Message); }
+        }
+
+        [HttpDelete("multipart")]
+        [Authorize("Pro")]
+        public async Task<IActionResult> AbortMultipartUpload([FromQuery] string name, [FromQuery] string uploadId)
+        {
+            var userId = this.User.FindFirstValue("sub");
+            try
+            {
+                await S3Service.AbortMultipartUploadAsync(userId, name, uploadId);
+                return Ok();
+            }
+            catch (Exception ex) { return BadRequest(ex.Message); }
+        }
+
+        [HttpPost("multipart")]
+        [Authorize("Pro")]
+        public async Task<IActionResult> CompleteMultipartUpload([FromBody] CompleteMultipartUploadRequestWrapper uploadRequestWrapper)
+        {
+            var userId = this.User.FindFirstValue("sub");
+            try
+            {
+                await S3Service.CompleteMultipartUploadAsync(userId, uploadRequestWrapper.ToRequest());
+                return Ok();
+            }
+            catch (Exception ex) { return BadRequest(ex.Message); }
+        }
+
+        [HttpGet]
+        [Authorize("Sync")]
+        public IActionResult Download([FromQuery] string name)
+        {
+            var userId = this.User.FindFirstValue("sub");
+            var url = S3Service.GetDownloadObjectUrl(userId, name);
+            if (url == null) return BadRequest("Could not create signed url.");
+            return Ok(url);
+        }
+
+        [HttpHead]
+        [Authorize("Sync")]
+        public async Task<IActionResult> Info([FromQuery] string name)
+        {
+            var userId = this.User.FindFirstValue("sub");
+            var size = await S3Service.GetObjectSizeAsync(userId, name);
+            HttpContext.Response.Headers.ContentLength = size;
+            return Ok();
+        }
+
+        [HttpDelete]
+        [Authorize("Sync")]
+        public async Task<IActionResult> DeleteAsync([FromQuery] string name)
+        {
+            try
+            {
+                var userId = this.User.FindFirstValue("sub");
+                await S3Service.DeleteObjectAsync(userId, name);
+                return Ok();
+            }
+            catch (Exception ex)
+            {
+                return BadRequest(ex.Message);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/Notesnook.API/Models/CompleteMultipartUploadRequestWrapper.cs b/Notesnook.API/Models/CompleteMultipartUploadRequestWrapper.cs
new file mode 100644
index 0000000..2fc9fd3
--- /dev/null
+++ b/Notesnook.API/Models/CompleteMultipartUploadRequestWrapper.cs
@@ -0,0 +1,30 @@
+using System.Collections.Generic;
+using Amazon.S3.Model;
+
+namespace Notesnook.API.Models;
+
+public class CompleteMultipartUploadRequestWrapper
+{
+    public string Key { get; set; }
+    public List<PartETagWrapper> PartETags { get; set; }
+    public string UploadId { get; set; }
+
+    public CompleteMultipartUploadRequest ToRequest()
+    {
+        CompleteMultipartUploadRequest completeMultipartUploadRequest = new CompleteMultipartUploadRequest();
+        completeMultipartUploadRequest.Key = Key;
+        completeMultipartUploadRequest.UploadId = UploadId;
+        completeMultipartUploadRequest.PartETags = [];
+        foreach (var partETagWrapper in PartETags)
+        {
+            var partETag = new PartETag
+            {
+                PartNumber = partETagWrapper.PartNumber,
+                ETag = partETagWrapper.ETag
+            };
+            completeMultipartUploadRequest.PartETags.Add(partETag);
+        }
+
+        return completeMultipartUploadRequest;
+    }
+}
\ No newline at end of file
diff --git a/Notesnook.API/Models/PartETagWrapper.cs b/Notesnook.API/Models/PartETagWrapper.cs
new file mode 100644
index 0000000..46b4c9f
--- /dev/null
+++ b/Notesnook.API/Models/PartETagWrapper.cs
@@ -0,0 +1,7 @@
+namespace Notesnook.API.Models;
+
+public class PartETagWrapper
+{
+    public int PartNumber { get; set; }
+    public string ETag { get; set; }
+}
\ No newline at end of file