diff --git a/cmake/sdks.cmake b/cmake/sdks.cmake
index 28c0db501f0..4182fcc0f66 100644
--- a/cmake/sdks.cmake
+++ b/cmake/sdks.cmake
@@ -2,7 +2,7 @@ include(sdksCommon)
 
 set(SDK_DEPENDENCY_BUILD_LIST "")
 
-set(NON_GENERATED_CLIENT_LIST access-management text-to-speech core queues s3-encryption identity-management transfer)  ## Manually generated code with a name mimicking client name
+set(NON_GENERATED_CLIENT_LIST access-management text-to-speech core queues s3-encryption identity-management transfer s3-transfer)  ## Manually generated code with a name mimicking client name
 
 if(REGENERATE_CLIENTS OR REGENERATE_DEFAULTS)
     message(STATUS "Checking for SDK generation requirements")
diff --git a/cmake/sdksCommon.cmake b/cmake/sdksCommon.cmake
index a0220c83188..fc3bcc18023 100644
--- a/cmake/sdksCommon.cmake
+++ b/cmake/sdksCommon.cmake
@@ -80,6 +80,7 @@ list(APPEND HIGH_LEVEL_SDK_LIST "access-management")
 list(APPEND HIGH_LEVEL_SDK_LIST "identity-management")
 list(APPEND HIGH_LEVEL_SDK_LIST "queues")
 list(APPEND HIGH_LEVEL_SDK_LIST "transfer")
+list(APPEND HIGH_LEVEL_SDK_LIST "s3-transfer")
 list(APPEND HIGH_LEVEL_SDK_LIST "s3-encryption")
 list(APPEND HIGH_LEVEL_SDK_LIST "text-to-speech")
 
@@ -141,6 +142,7 @@ list(APPEND SDK_DEPENDENCY_LIST "queues:sqs,core")
 list(APPEND SDK_DEPENDENCY_LIST "s3-encryption:s3,kms,core")
 list(APPEND SDK_DEPENDENCY_LIST "text-to-speech:polly,core")
 list(APPEND SDK_DEPENDENCY_LIST "transfer:s3,core")
+list(APPEND SDK_DEPENDENCY_LIST "s3-transfer:s3,core")
 
 set(TEST_DEPENDENCY_LIST "")
 list(APPEND TEST_DEPENDENCY_LIST "cognito-identity:access-management,iam,core")
diff --git a/src/aws-cpp-sdk-s3-transfer/CMakeLists.txt b/src/aws-cpp-sdk-s3-transfer/CMakeLists.txt
new file mode 100644
index 00000000000..1dc3248f857
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/CMakeLists.txt
@@ -0,0 +1,61 @@
+add_project(aws-cpp-sdk-s3-transfer
+        "High-level CRT-backed C++ SDK for file transfer to/from AWS S3"
+        aws-cpp-sdk-s3
+        aws-cpp-sdk-core)
+
+file( GLOB S3_TRANSFER_HEADERS "include/aws/s3-transfer/*.h" )
+
+file( GLOB S3_TRANSFER_SOURCE "source/s3-transfer/*.cpp" )
+
+file( GLOB S3_TRANSFER_INTERNAL_HEADERS "include/aws/s3-transfer/internal/*.h" )
+file( GLOB S3_TRANSFER_INTERNAL_SOURCE "source/s3-transfer/internal/*.cpp" )
+
+if(MSVC)
+    source_group("Header Files\\aws\\s3-transfer" FILES ${S3_TRANSFER_HEADERS})
+    source_group("Source Files\\s3-transfer" FILES ${S3_TRANSFER_SOURCE})
+    source_group("Header Files\\aws\\s3-transfer\\internal" FILES ${S3_TRANSFER_INTERNAL_HEADERS})
+    source_group("Source Files\\s3-transfer\\internal" FILES ${S3_TRANSFER_INTERNAL_SOURCE})
+endif()
+
+file(GLOB ALL_S3_TRANSFER_HEADERS
+        ${S3_TRANSFER_HEADERS}
+        ${S3_TRANSFER_INTERNAL_HEADERS}
+)
+
+file(GLOB ALL_S3_TRANSFER_SOURCE
+        ${S3_TRANSFER_SOURCE}
+        ${S3_TRANSFER_INTERNAL_SOURCE}
+)
+
+file(GLOB ALL_S3_TRANSFER
+        ${ALL_S3_TRANSFER_HEADERS}
+        ${ALL_S3_TRANSFER_SOURCE}
+)
+
+set(S3_TRANSFER_INCLUDES
+        "${CMAKE_CURRENT_SOURCE_DIR}/include/"
+)
+
+include_directories(${S3_TRANSFER_INCLUDES})
+
+if(USE_WINDOWS_DLL_SEMANTICS AND BUILD_SHARED_LIBS)
+    add_definitions("-DAWS_S3_TRANSFER_EXPORTS")
+endif()
+
+add_library(${PROJECT_NAME} ${ALL_S3_TRANSFER})
+add_library(AWS::${PROJECT_NAME} ALIAS ${PROJECT_NAME})
+
+target_include_directories(${PROJECT_NAME} PUBLIC
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+        $<INSTALL_INTERFACE:include>)
+target_link_libraries(${PROJECT_NAME} PRIVATE ${PLATFORM_DEP_LIBS} ${PROJECT_LIBS})
+
+set_compiler_flags(${PROJECT_NAME})
+set_compiler_warnings(${PROJECT_NAME})
+
+setup_install()
+
+install (FILES ${S3_TRANSFER_HEADERS}          DESTINATION ${INCLUDE_DIRECTORY}/aws/s3-transfer)
+install (FILES ${S3_TRANSFER_INTERNAL_HEADERS} DESTINATION ${INCLUDE_DIRECTORY}/aws/s3-transfer/internal)
+
+do_packaging()
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadHandle.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadHandle.h
new file mode 100644
index 00000000000..895f813cb0e
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadHandle.h
@@ -0,0 +1,47 @@
+/**
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <future>
+#include <memory>
+#include <aws/s3-transfer/DownloadResponse.h>
+
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+class DownloadHandleImpl;
+
+/**
+ * Returned from S3TransferManager::Download to represent a single in-flight download. The
+ * handle is freely copyable; all copies share the same underlying transfer state.
+ */
+class AWS_S3_TRANSFER_API DownloadHandle final {
+public:
+  DownloadHandle();
+  ~DownloadHandle();
+  DownloadHandle(DownloadHandle&&) noexcept;
+  DownloadHandle& operator=(DownloadHandle&&) noexcept;
+
+  /**
+   * Returns a future that resolves once the transfer finishes, succeeds, or fails.
+   */
+  std::future<DownloadOutcome> CompletionFuture();
+
+  /**
+   * Requests cancellation of the in-flight download. Returns immediately; the future
+   * returned by CompletionFuture will resolve with a failure once the cancel takes effect.
+   */
+  void Cancel();
+
+private:
+  Aws::UniquePtr<DownloadHandleImpl> m_impl;
+};
+
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadProgressListener.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadProgressListener.h
new file mode 100644
index 00000000000..6e5f2a9a378
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadProgressListener.h
@@ -0,0 +1,26 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/s3-transfer/ProgressListener.h>
+#include <aws/s3-transfer/DownloadProgressSnapshot.h>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+class DownloadRequest;
+
+/**
+ * Callback interface for receiving event-driven updates throughout the lifecycle of a download.
+ * Subclass and override the events of interest; default implementations are empty so unused
+ * callbacks can be ignored. Listeners may be registered on the request or on the manager.
+ */
+class AWS_S3_TRANSFER_API DownloadProgressListener
+    : public ProgressListener<DownloadRequest, DownloadProgressSnapshot> {};
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadProgressSnapshot.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadProgressSnapshot.h
new file mode 100644
index 00000000000..2e0791a9e0a
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadProgressSnapshot.h
@@ -0,0 +1,26 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/s3-transfer/ProgressSnapshot.h>
+#include <aws/s3-transfer/DownloadResponse.h>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+/**
+ * Immutable snapshot of download progress passed to DownloadProgressListener callbacks.
+ * Captures bytes transferred, total bytes (known after the GetObject response is received),
+ * and the response once available.
+ */
+class AWS_S3_TRANSFER_API DownloadProgressSnapshot final : public ProgressSnapshot<DownloadResponse> {
+ public:
+  using ProgressSnapshot<DownloadResponse>::ProgressSnapshot;
+};
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadRequest.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadRequest.h
new file mode 100644
index 00000000000..69eb938e2d5
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadRequest.h
@@ -0,0 +1,53 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/s3-transfer/DownloadProgressListener.h>
+#include <aws/core/utils/memory/stl/AWSString.h>
+#include <aws/core/utils/memory/stl/AWSVector.h>
+#include <aws/core/utils/stream/ResponseStream.h>
+#include <aws/s3/model/GetObjectRequest.h>
+#include <memory>
+#include <utility>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+/**
+ * Request type for S3TransferManager::Download. Carries the inner S3 GetObjectRequest along
+ * with the local destination (file path or stream factory) and any request-level progress
+ * listeners. The transfer manager parallelizes large objects via ranged GETs internally.
+ */
+class AWS_S3_TRANSFER_API DownloadRequest final {
+ public:
+  explicit DownloadRequest(
+    Aws::S3::Model::GetObjectRequest s3Request,
+    Aws::String destinationFilePath,
+    Aws::IOStreamFactory responseStreamFactory,
+    Aws::Vector<std::shared_ptr<DownloadProgressListener>> transferListeners = {})
+  : m_s3Request(std::move(s3Request)),
+    m_destinationFilePath(std::move(destinationFilePath)),
+    m_responseStreamFactory(std::move(responseStreamFactory)),
+    m_transferListeners(std::move(transferListeners)) {}
+
+  inline const Aws::S3::Model::GetObjectRequest& GetS3Request() const { return m_s3Request; }
+  inline const Aws::String& GetDestinationFilePath() const { return m_destinationFilePath; }
+  inline const Aws::IOStreamFactory& GetResponseStreamFactory() const { return m_responseStreamFactory; }
+  inline const Aws::Vector<std::shared_ptr<DownloadProgressListener>>& GetTransferListeners() const {
+    return m_transferListeners;
+  }
+
+
+ private:
+  Aws::S3::Model::GetObjectRequest m_s3Request;
+  Aws::String m_destinationFilePath;
+  Aws::IOStreamFactory m_responseStreamFactory;
+  Aws::Vector<std::shared_ptr<DownloadProgressListener>> m_transferListeners;
+};
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadResponse.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadResponse.h
new file mode 100644
index 00000000000..8aa84699b28
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/DownloadResponse.h
@@ -0,0 +1,46 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/core/client/AWSError.h>
+#include <aws/core/utils/Outcome.h>
+#include <aws/s3/S3Errors.h>
+#include <aws/s3/model/GetObjectResult.h>
+#include <utility>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+/**
+ * Response type returned via the DownloadHandle's future once the transfer completes. Wraps
+ * the underlying S3 GetObjectResult with whole-object content length and range, regardless
+ * of how many ranged GETs were issued internally.
+ */
+class AWS_S3_TRANSFER_API DownloadResponse final {
+ public:
+  inline const Aws::S3::Model::GetObjectResult& GetS3Result() const { return m_s3Result; }
+  inline bool S3ResultHasBeenSet() const { return m_s3ResultHasBeenSet; }
+  template <typename GetObjectResultT = Aws::S3::Model::GetObjectResult>
+  void SetS3Result(GetObjectResultT&& getS3Result) {
+    m_s3ResultHasBeenSet = true;
+    m_s3Result = std::forward<GetObjectResultT>(getS3Result);
+  }
+  template <typename GetObjectResultT = Aws::S3::Model::GetObjectResult>
+  DownloadResponse& WithS3Result(GetObjectResultT&& getS3Result) {
+    SetS3Result(std::forward<GetObjectResultT>(getS3Result));
+    return *this;
+  }
+
+ private:
+  Aws::S3::Model::GetObjectResult m_s3Result;
+  bool m_s3ResultHasBeenSet = false;
+};
+
+using DownloadOutcome = Aws::Utils::Outcome<DownloadResponse, Aws::Client::AWSError<Aws::S3::S3Errors>>;
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/ProgressListener.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/ProgressListener.h
new file mode 100644
index 00000000000..d345f10242b
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/ProgressListener.h
@@ -0,0 +1,47 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+/**
+ * Callback interface for receiving event-driven updates throughout the lifecycle of a transfer.
+ * Subclass and override the events of interest; default implementations are empty so unused
+ * callbacks can be ignored. Listeners may be registered on the request or on the manager.
+ * Specialized via the UploadProgressListener and DownloadProgressListener type aliases.
+ */
+template <typename RequestT, typename SnapshotT>
+class ProgressListener {
+ public:
+  virtual ~ProgressListener() = default;
+
+  /**
+   * Invoked exactly once when the transfer begins, before any bytes have been transferred.
+   */
+  virtual void OnTransferInitiated(const RequestT& /*request*/, const SnapshotT& /*snapshot*/) {}
+
+  /**
+   * Invoked as bytes are transferred. Called at least once for a successful transfer
+   * and may be called many times depending on object size and I/O buffer sizes.
+   */
+  virtual void OnBytesTransferred(const RequestT& /*request*/, const SnapshotT& /*snapshot*/) {}
+
+  /**
+   * Invoked exactly once when the transfer completes successfully.
+   */
+  virtual void OnTransferComplete(const RequestT& /*request*/, const SnapshotT& /*snapshot*/) {}
+
+  /**
+   * Invoked exactly once when the transfer fails or is cancelled.
+   */
+  virtual void OnTransferFailed(const RequestT& /*request*/, const SnapshotT& /*snapshot*/) {}
+};
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/ProgressSnapshot.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/ProgressSnapshot.h
new file mode 100644
index 00000000000..18ef7898d85
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/ProgressSnapshot.h
@@ -0,0 +1,49 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <cstdint>
+#include <memory>
+#include <utility>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+/**
+ * Immutable snapshot of transfer progress passed to ProgressListener callbacks. Captures
+ * bytes transferred, total bytes, and the response once available. Specialized via the
+ * UploadProgressSnapshot and DownloadProgressSnapshot type aliases.
+ */
+template <typename ResponseT>
+class ProgressSnapshot {
+ public:
+  virtual ~ProgressSnapshot() = default;
+
+  ProgressSnapshot(uint64_t transferredBytes,
+                   uint64_t totalBytes,
+                   std::shared_ptr<ResponseT> response,
+                   bool totalBytesHasBeenSet)
+      : m_transferredBytes(transferredBytes),
+        m_totalBytes(totalBytes),
+        m_response(std::move(response)),
+        m_totalBytesHasBeenSet(totalBytesHasBeenSet) {}
+
+  inline uint64_t GetTransferredBytes() const { return m_transferredBytes; }
+  inline uint64_t GetTotalBytes() const { return m_totalBytes; }
+  inline bool TotalBytesHasBeenSet() const { return m_totalBytesHasBeenSet; }
+  inline const std::shared_ptr<ResponseT>& GetResponse() const { return m_response; }
+  inline bool ResponseHasBeenSet() const { return m_response != nullptr; }
+
+ private:
+  uint64_t m_transferredBytes = 0;
+  uint64_t m_totalBytes = 0;
+  std::shared_ptr<ResponseT> m_response;
+  bool m_totalBytesHasBeenSet = false;
+};
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3TransferManager.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3TransferManager.h
new file mode 100644
index 00000000000..52c5b03ae46
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3TransferManager.h
@@ -0,0 +1,51 @@
+/**
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/s3-transfer/S3TransferManagerConfiguration.h>
+#include <aws/s3-transfer/UploadRequest.h>
+#include <aws/s3-transfer/DownloadRequest.h>
+#include <aws/s3-transfer/UploadHandle.h>
+#include <aws/s3-transfer/DownloadHandle.h>
+#include <aws/core/utils/memory/AWSMemory.h>
+namespace Aws {
+  namespace S3 {
+  namespace Transfer {
+  class S3TransferManagerImpl;
+
+  /**
+   * Customers construct an instance directly. The manager owns the underlying CRT
+   * client; it is movable but not copyable.
+   */
+  class AWS_S3_TRANSFER_API S3TransferManager final {
+  public:
+    explicit S3TransferManager(const S3TransferManagerConfiguration& config);
+    ~S3TransferManager();
+
+    S3TransferManager(const S3TransferManager&) = delete;
+    S3TransferManager& operator=(const S3TransferManager&) = delete;
+
+
+    /**
+     * Begin uploading the object described by request. Returns immediately with a handle
+     * that can be used to wait for completion or to cancel the in-flight transfer.
+     */
+    UploadHandle Upload(const UploadRequest& request);
+
+    /**
+     * Begin downloading the object described by request. Returns immediately with a handle
+     * that can be used to wait for completion or to cancel the in-flight transfer.
+     */
+    DownloadHandle Download(const DownloadRequest& request);
+
+  private:
+    Aws::UniquePtr<S3TransferManagerImpl> m_impl;
+  };
+  }
+  }
+  }
+
+
+
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3TransferManagerConfiguration.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3TransferManagerConfiguration.h
new file mode 100644
index 00000000000..f8cd24fa03f
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3TransferManagerConfiguration.h
@@ -0,0 +1,18 @@
+/**
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+
+
+namespace Aws {
+  namespace S3 {
+    namespace Transfer {
+      class AWS_S3_TRANSFER_API S3TransferManagerConfiguration {
+        //need to fill in class definition later
+      };
+    }
+  }
+}
+
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3Transfer_EXPORTS.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3Transfer_EXPORTS.h
new file mode 100644
index 00000000000..fe7636bb906
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/S3Transfer_EXPORTS.h
@@ -0,0 +1,28 @@
+/**
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+
+#ifdef _MSC_VER
+    //disable windows complaining about max template size.
+    #pragma warning (disable : 4503)
+#endif
+
+#if defined (USE_WINDOWS_DLL_SEMANTICS) || defined (_WIN32)
+    #ifdef _MSC_VER
+        #pragma warning(disable : 4251)
+    #endif // _MSC_VER
+
+    #ifdef USE_IMPORT_EXPORT
+      #ifdef AWS_S3_TRANSFER_EXPORTS
+        #define AWS_S3_TRANSFER_API __declspec(dllexport)
+      #else
+        #define AWS_S3_TRANSFER_API __declspec(dllimport)
+      #endif // AWS_S3_TRANSFER_EXPORTS
+    #else // USE_IMPORT_EXPORT
+       #define AWS_S3_TRANSFER_API
+    #endif // USE_IMPORT_EXPORT
+#else // defined (USE_WINDOWS_DLL_SEMANTICS) || defined (_WIN32)
+    #define AWS_S3_TRANSFER_API
+#endif // defined (USE_WINDOWS_DLL_SEMANTICS) || defined (_WIN32)
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadHandle.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadHandle.h
new file mode 100644
index 00000000000..5e6b893a96d
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadHandle.h
@@ -0,0 +1,48 @@
+/**
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <future>
+#include <memory>
+#include <aws/s3-transfer/UploadResponse.h>
+
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+class UploadHandleImpl;
+
+/**
+ * Returned from S3TransferManager::Upload to represent a single in-flight upload. The
+ * handle is freely copyable; all copies share the same underlying transfer state.
+ */
+class AWS_S3_TRANSFER_API UploadHandle final {
+public:
+  UploadHandle();
+  ~UploadHandle();
+  UploadHandle(UploadHandle&&) noexcept;
+  UploadHandle& operator=(UploadHandle&&) noexcept;
+
+
+  /**
+   * Returns a future that resolves once the transfer finishes, succeeds, or fails.
+   */
+  std::future<UploadOutcome> CompletionFuture();
+
+  /**
+   * Requests cancellation of the in-flight upload. Returns immediately; the future
+   * returned by CompletionFuture will resolve with a failure once the cancel takes effect.
+   */
+  void Cancel();
+
+private:
+  Aws::UniquePtr<UploadHandleImpl> m_impl;
+};
+
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadProgressListener.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadProgressListener.h
new file mode 100644
index 00000000000..dc018930441
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadProgressListener.h
@@ -0,0 +1,26 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/s3-transfer/ProgressListener.h>
+#include <aws/s3-transfer/UploadProgressSnapshot.h>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+class UploadRequest;
+
+/**
+ * Callback interface for receiving event-driven updates throughout the lifecycle of an upload.
+ * Subclass and override the events of interest; default implementations are empty so unused
+ * callbacks can be ignored. Listeners may be registered on the request or on the manager.
+ */
+class AWS_S3_TRANSFER_API UploadProgressListener
+    : public ProgressListener<UploadRequest, UploadProgressSnapshot> {};
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadProgressSnapshot.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadProgressSnapshot.h
new file mode 100644
index 00000000000..430b40dca97
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadProgressSnapshot.h
@@ -0,0 +1,25 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/s3-transfer/ProgressSnapshot.h>
+#include <aws/s3-transfer/UploadResponse.h>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+/**
+ * Immutable snapshot of upload progress passed to UploadProgressListener callbacks. Captures
+ * bytes transferred, total bytes (known up-front for uploads), and the response once available.
+ */
+class AWS_S3_TRANSFER_API UploadProgressSnapshot final : public ProgressSnapshot<UploadResponse> {
+ public:
+  using ProgressSnapshot<UploadResponse>::ProgressSnapshot;
+};
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadRequest.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadRequest.h
new file mode 100644
index 00000000000..b284a7bead1
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadRequest.h
@@ -0,0 +1,53 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/s3-transfer/UploadProgressListener.h>
+#include <aws/core/utils/memory/stl/AWSString.h>
+#include <aws/core/utils/memory/stl/AWSVector.h>
+#include <aws/s3/model/PutObjectRequest.h>
+#include <memory>
+#include <utility>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+/**
+ * Request type for S3TransferManager::Upload. Carries the inner S3 PutObjectRequest along
+ * with the local source (file path or stream) and any request-level progress listeners.
+ * The transfer manager chooses between a single PutObject and a multipart upload based on
+ * the configured threshold.
+ */
+class AWS_S3_TRANSFER_API UploadRequest final {
+ public:
+  explicit UploadRequest(
+    Aws::S3::Model::PutObjectRequest s3Request,
+    Aws::String sourceFilePath,
+    std::shared_ptr<Aws::IOStream> body,
+    Aws::Vector<std::shared_ptr<UploadProgressListener>> transferListeners = {})
+  : m_s3Request(std::move(s3Request)),
+    m_sourceFilePath(std::move(sourceFilePath)),
+    m_body(std::move(body)),
+    m_transferListeners(std::move(transferListeners)) {}
+
+  inline const Aws::S3::Model::PutObjectRequest& GetS3Request() const {return m_s3Request; }
+  inline const Aws::String& GetSourceFilePath() const {return m_sourceFilePath;}
+  inline const std::shared_ptr<Aws::IOStream>& GetBody() const {return m_body;}
+  inline const Aws::Vector<std::shared_ptr<UploadProgressListener>>& GetTransferListeners() const {
+    return m_transferListeners;
+  }
+
+
+ private:
+  Aws::S3::Model::PutObjectRequest m_s3Request;
+  Aws::String m_sourceFilePath;
+  std::shared_ptr<Aws::IOStream> m_body;
+  Aws::Vector<std::shared_ptr<UploadProgressListener>> m_transferListeners;
+};
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadResponse.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadResponse.h
new file mode 100644
index 00000000000..e5618229def
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/UploadResponse.h
@@ -0,0 +1,46 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+#include <aws/s3-transfer/S3Transfer_EXPORTS.h>
+#include <aws/core/client/AWSError.h>
+#include <aws/core/utils/Outcome.h>
+#include <aws/s3/S3Errors.h>
+#include <aws/s3/model/PutObjectResult.h>
+#include <utility>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+/**
+ * Response type returned via the UploadHandle's future once the transfer completes. Wraps
+ * the underlying S3 PutObjectResult, populated from either the single PutObject response
+ * or the CompleteMultipartUpload response depending on the path taken.
+ */
+class AWS_S3_TRANSFER_API UploadResponse final {
+ public:
+  inline const Aws::S3::Model::PutObjectResult& GetS3Result() const { return m_s3Result; }
+  inline bool S3ResultHasBeenSet() const { return m_s3ResultHasBeenSet; }
+  template <typename S3ResultT = Aws::S3::Model::PutObjectResult>
+  void SetS3Result(S3ResultT&& s3Result) {
+    m_s3ResultHasBeenSet = true;
+    m_s3Result = std::forward<S3ResultT>(s3Result);
+  }
+  template <typename S3ResultT = Aws::S3::Model::PutObjectResult>
+  UploadResponse& WithS3Result(S3ResultT&& s3Result) {
+    SetS3Result(std::forward<S3ResultT>(s3Result));
+    return *this;
+  }
+
+ private:
+  Aws::S3::Model::PutObjectResult m_s3Result;
+  bool m_s3ResultHasBeenSet = false;
+};
+
+using UploadOutcome = Aws::Utils::Outcome<UploadResponse, Aws::Client::AWSError<Aws::S3::S3Errors>>;
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/internal/CrtOperations.h b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/internal/CrtOperations.h
new file mode 100644
index 00000000000..b45a188732f
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/include/aws/s3-transfer/internal/CrtOperations.h
@@ -0,0 +1,43 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#pragma once
+
+#include <aws/s3-transfer/UploadHandle.h>
+#include <aws/s3-transfer/DownloadHandle.h>
+#include <aws/s3-transfer/UploadRequest.h>
+#include <aws/s3-transfer/DownloadRequest.h>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+
+class S3TransferManagerImpl;
+
+namespace Internal {
+
+/**
+   * Bridges TM 2.0 to the aws-crt-cpp S3 wrapper. Stays in C++; does not call
+   * aws-c-s3 directly. Internal; not part of the public API.
+  */
+class CrtOperations final {
+
+ public:
+  /**
+   * Dispatch an upload as a CRT meta request. Returns a handle bound to the
+   * in-flight request.
+   */
+  static UploadHandle DispatchUpload(S3TransferManagerImpl& impl, const UploadRequest& request);
+
+  /**
+   * Dispatch a download as a CRT meta request. Returns a handle bound to the
+   * in-flight request.
+   */
+  static DownloadHandle DispatchDownload(S3TransferManagerImpl& impl, const DownloadRequest& request);
+};
+
+}
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/DownloadHandle.cpp b/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/DownloadHandle.cpp
new file mode 100644
index 00000000000..e8189b20e69
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/DownloadHandle.cpp
@@ -0,0 +1,26 @@
+/**
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+   * SPDX-License-Identifier: Apache-2.0.
+   */
+  #include <aws/s3-transfer/DownloadHandle.h>
+
+  namespace Aws {
+  namespace S3 {
+  namespace Transfer {
+  class DownloadHandleImpl {
+
+  };
+  DownloadHandle::~DownloadHandle() = default;
+  DownloadHandle::DownloadHandle() = default;
+  DownloadHandle::DownloadHandle(DownloadHandle&&) noexcept = default;
+  DownloadHandle& DownloadHandle::operator=(DownloadHandle&&) noexcept = default;
+
+  std::future<DownloadOutcome> DownloadHandle::CompletionFuture() {
+    return {};
+  }
+  void DownloadHandle::Cancel() {
+
+  }
+  }
+  }
+  }
diff --git a/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/S3TransferManager.cpp b/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/S3TransferManager.cpp
new file mode 100644
index 00000000000..baf1d513aa5
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/S3TransferManager.cpp
@@ -0,0 +1,31 @@
+/**
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+   * SPDX-License-Identifier: Apache-2.0.
+   */
+#include <aws/s3-transfer/S3TransferManager.h>
+#include <aws/core/utils/memory/AWSMemory.h>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+class S3TransferManagerImpl {
+
+};
+S3TransferManager::~S3TransferManager() = default;
+
+S3TransferManager::S3TransferManager(const S3TransferManagerConfiguration& ) :
+m_impl(Aws::MakeUnique<S3TransferManagerImpl>("S3TransferManager")) {
+
+}
+
+UploadHandle S3TransferManager::Upload(const UploadRequest&) {
+  return UploadHandle();
+}
+
+DownloadHandle S3TransferManager::Download(const DownloadRequest&) {
+  return DownloadHandle();
+}
+
+}
+}
+}
diff --git a/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/UploadHandle.cpp b/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/UploadHandle.cpp
new file mode 100644
index 00000000000..2d46c4d976a
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/UploadHandle.cpp
@@ -0,0 +1,27 @@
+/**
+* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+   * SPDX-License-Identifier: Apache-2.0.
+   */
+  #include <aws/s3-transfer/UploadHandle.h>
+
+  namespace Aws {
+  namespace S3 {
+  namespace Transfer {
+  class UploadHandleImpl {
+
+  };
+  UploadHandle::~UploadHandle() = default;
+  UploadHandle::UploadHandle() = default;
+
+  UploadHandle::UploadHandle(UploadHandle&&) noexcept = default;
+  UploadHandle& UploadHandle::operator=(UploadHandle&&) noexcept = default;
+
+  std::future<UploadOutcome> UploadHandle::CompletionFuture() {
+    return {};
+  }
+  void UploadHandle::Cancel() {
+
+  }
+  }
+  }
+  }
diff --git a/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/internal/CrtOperations.cpp b/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/internal/CrtOperations.cpp
new file mode 100644
index 00000000000..6474dfc6802
--- /dev/null
+++ b/src/aws-cpp-sdk-s3-transfer/source/s3-transfer/internal/CrtOperations.cpp
@@ -0,0 +1,24 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+
+#include <aws/s3-transfer/internal/CrtOperations.h>
+
+namespace Aws {
+namespace S3 {
+namespace Transfer {
+namespace Internal {
+
+UploadHandle CrtOperations::DispatchUpload(S3TransferManagerImpl&, const UploadRequest&) {
+  return UploadHandle();
+}
+
+DownloadHandle CrtOperations::DispatchDownload(S3TransferManagerImpl&, const DownloadRequest&) {
+  return DownloadHandle();
+}
+
+}
+}
+}
+}