diff --git a/haxe_libraries/tink_core.hxml b/haxe_libraries/tink_core.hxml
index 4f2a5fc..8160c6b 100644
--- a/haxe_libraries/tink_core.hxml
+++ b/haxe_libraries/tink_core.hxml
@@ -1,3 +1,3 @@
--D tink_core=1.24.0
-# @install: lix --silent download "haxelib:/tink_core#1.24.0" into tink_core/1.24.0/haxelib
--cp ${HAXE_LIBCACHE}/tink_core/1.24.0/haxelib/src
+# @install: lix --silent download "gh://github.com/haxetink/tink_core#a14155a83f41279a9804d2733114f1404608d24f" into tink_core/1.27.1/github/a14155a83f41279a9804d2733114f1404608d24f
+-cp ${HAXE_LIBCACHE}/tink_core/1.27.1/github/a14155a83f41279a9804d2733114f1404608d24f/src
+-D tink_core=1.27.1
\ No newline at end of file
diff --git a/src/tink/http/Client.hx b/src/tink/http/Client.hx
index a902579..fcca10d 100644
--- a/src/tink/http/Client.hx
+++ b/src/tink/http/Client.hx
@@ -1,6 +1,7 @@
 package tink.http;
 
 import haxe.extern.Rest;
+import tink.core.Progress;
 import tink.http.Request;
 import tink.http.Response;
 import tink.http.Fetch;
@@ -29,7 +30,11 @@ interface ClientObject {
    *  @param req - The HTTP request
    *  @return The HTTP response
    */
-  function request(req:OutgoingRequest):Promise<IncomingResponse>;
+  function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse>;
+}
+
+typedef ClientRequestHandlers = {
+  ?upload:ProgressValue->Void,
 }
 
 typedef Processors = { 
@@ -60,11 +65,11 @@ private class CustomClient implements ClientObject {
       else
         value;
 
-  public function request(req) 
+  public function request(req, ?handlers) 
     return 
       pipe(req, preprocessors)
         .next(function (req) 
-          return real.request(req)
+          return real.request(req, handlers)
             .next(pipe.bind(_, postprocessors == null ? null : [for (p in postprocessors) p(req)]))
         );
 
diff --git a/src/tink/http/Fetch.hx b/src/tink/http/Fetch.hx
index c7dc7af..d93e103 100644
--- a/src/tink/http/Fetch.hx
+++ b/src/tink/http/Fetch.hx
@@ -50,7 +50,7 @@ class Fetch {
 			client.request(new OutgoingRequest(
 				new OutgoingRequestHeader(method, url, headers),
 				body
-			)).handle(function(res) {
+			), options.handlers).handle(function(res) {
 				switch res {
 					case Success(res):
 						switch res.header.statusCode {
@@ -101,6 +101,7 @@ typedef FetchOptions = {
 	?client:ClientType,
 	?followRedirect:Bool,
 	?augment:Processors,
+	?handlers:ClientRequestHandlers,
 }
 
 enum ClientType {
diff --git a/src/tink/http/clients/CurlClient.hx b/src/tink/http/clients/CurlClient.hx
index 0cebe55..d4d3ab0 100644
--- a/src/tink/http/clients/CurlClient.hx
+++ b/src/tink/http/clients/CurlClient.hx
@@ -16,7 +16,7 @@ class CurlClient implements ClientObject {
     if(curl != null) this.curl = curl;
   }
   
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
     return switch Helpers.checkScheme(req.header.url.scheme) {
       case Some(e):
         Promise.reject(e);
diff --git a/src/tink/http/clients/FlashClient.hx b/src/tink/http/clients/FlashClient.hx
index 37468cf..5bb2b36 100644
--- a/src/tink/http/clients/FlashClient.hx
+++ b/src/tink/http/clients/FlashClient.hx
@@ -25,7 +25,7 @@ class FlashClient implements ClientObject {
   
   public function new() {}
   
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
     return Future.async(function(cb) {
       switch Helpers.checkScheme(req.header.url.scheme) {
         case Some(e):
diff --git a/src/tink/http/clients/FlashSocketClient.hx b/src/tink/http/clients/FlashSocketClient.hx
index bc13b2e..bc62803 100644
--- a/src/tink/http/clients/FlashSocketClient.hx
+++ b/src/tink/http/clients/FlashSocketClient.hx
@@ -34,7 +34,7 @@ class FlashSocketClient implements ClientObject {
   function getSocket(secure:Bool):Socket
     return secure ? new SecureSocket() : new Socket();
   
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
     return Future.async(function(cb) {
       
       switch req.header.byName('connection') {
diff --git a/src/tink/http/clients/JsClient.hx b/src/tink/http/clients/JsClient.hx
index cbfe704..366834c 100644
--- a/src/tink/http/clients/JsClient.hx
+++ b/src/tink/http/clients/JsClient.hx
@@ -1,6 +1,7 @@
 package tink.http.clients;
 
 import haxe.io.Bytes;
+import tink.core.Progress;
 import tink.http.Client;
 import tink.http.Header;
 import tink.http.Request;
@@ -22,7 +23,7 @@ class JsClient implements ClientObject {
     if(credentials) this.credentials = true;
   }
   
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
     return Future.async(function(cb) {
       var http = getHttp();
       // if(req.header.url.scheme == null) cb(Failure(Helper.missingSchemeError()));
@@ -56,6 +57,11 @@ class JsClient implements ClientObject {
           );
         }
       }
+      switch handlers {
+        case null | {upload: null}: // skip
+        case {upload: upload}: 
+          http.upload.onprogress = function(e) upload(new ProgressValue(e.loaded, Some(e.total)));
+      }
       http.onerror = function(e) {
         cb(Failure(Error.withData(502, 'XMLHttpRequest Error', {request: req, error: e})));
       }
diff --git a/src/tink/http/clients/LocalContainerClient.hx b/src/tink/http/clients/LocalContainerClient.hx
index 7be8342..a833959 100644
--- a/src/tink/http/clients/LocalContainerClient.hx
+++ b/src/tink/http/clients/LocalContainerClient.hx
@@ -15,7 +15,7 @@ class LocalContainerClient implements ClientObject {
     this.container = container;
   }
   
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
       return container.serve(new IncomingRequest(
         '127.0.0.1',
         new IncomingRequestHeader(req.header.method, req.header.url.pathWithQuery, 'HTTP/1.1', @:privateAccess req.header.fields),
diff --git a/src/tink/http/clients/NodeClient.hx b/src/tink/http/clients/NodeClient.hx
index 91e7d07..e3c6509 100644
--- a/src/tink/http/clients/NodeClient.hx
+++ b/src/tink/http/clients/NodeClient.hx
@@ -21,7 +21,7 @@ class NodeClient implements ClientObject {
   
   public function new() { }
   
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
     return switch Helpers.checkScheme(req.header.url.scheme) {
       case Some(e):
         Promise.reject(e);
diff --git a/src/tink/http/clients/PhpClient.hx b/src/tink/http/clients/PhpClient.hx
index 1760a13..cc3686c 100644
--- a/src/tink/http/clients/PhpClient.hx
+++ b/src/tink/http/clients/PhpClient.hx
@@ -12,7 +12,7 @@ using StringTools;
 class PhpClient implements ClientObject {
   public function new() {}
   
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
     return Future.async(function(cb) {
       req.body.all().handle(function(chunk) {
         var options = php.Lib.associativeArrayOfObject({
diff --git a/src/tink/http/clients/SocketClient.hx b/src/tink/http/clients/SocketClient.hx
index 1cfff83..7eae624 100644
--- a/src/tink/http/clients/SocketClient.hx
+++ b/src/tink/http/clients/SocketClient.hx
@@ -18,7 +18,7 @@ class SocketClient implements ClientObject {
     this.worker = worker.ensure();
   }
   
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
     return Future.async(function(cb) {
       switch Helpers.checkScheme(req.header.url.scheme) {
         case Some(e):
diff --git a/src/tink/http/clients/StdClient.hx b/src/tink/http/clients/StdClient.hx
index 157990d..a2beb28 100644
--- a/src/tink/http/clients/StdClient.hx
+++ b/src/tink/http/clients/StdClient.hx
@@ -15,7 +15,7 @@ class StdClient implements ClientObject {
   public function new(?worker:Worker) {
     this.worker = worker.ensure();
   }
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> 
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> 
     return Future.async(function (cb) {
             
       var r = new haxe.Http(req.header.url);
diff --git a/src/tink/http/clients/TcpClient.hx b/src/tink/http/clients/TcpClient.hx
index 50dcd92..14696ac 100644
--- a/src/tink/http/clients/TcpClient.hx
+++ b/src/tink/http/clients/TcpClient.hx
@@ -12,7 +12,7 @@ using tink.CoreApi;
 @:require('tink_tcp')
 class TcpClient implements ClientObject { 
   public function new() {}
-  public function request(req:OutgoingRequest):Promise<IncomingResponse> {
+  public function request(req:OutgoingRequest, ?handlers:ClientRequestHandlers):Promise<IncomingResponse> {
     return Future.async(function(cb) {
       switch Helpers.checkScheme(req.header.url.scheme) {
         case Some(e): cb(Failure(e));