diff --git a/rhodecode/lib/middleware/simplehg.py b/rhodecode/lib/middleware/simplehg.py
--- a/rhodecode/lib/middleware/simplehg.py
+++ b/rhodecode/lib/middleware/simplehg.py
@@ -22,6 +22,7 @@ SimpleHG middleware for handling mercuri
 (push/clone etc.). It's implemented with basic auth function
 """
 
+import copy
 import logging
 import urllib.parse
 import urllib.request
@@ -32,6 +33,7 @@ from rhodecode.lib import utils
 from rhodecode.lib.ext_json import json
 from rhodecode.lib.middleware import simplevcs
 from rhodecode.lib.middleware.utils import get_path_info
+from rhodecode.lib.str_utils import safe_str
 
 log = logging.getLogger(__name__)
 
@@ -95,7 +97,7 @@ class SimpleHg(simplevcs.SimpleVCS):
         i = 1
         chunks = []  # gather chunks stored in multiple 'hgarg_N'
         while True:
-            head = environ.get('HTTP_X_HGARG_{}'.format(i))
+            head = environ.get(f'HTTP_X_HGARG_{i}')
             if not head:
                 break
             i += 1
@@ -118,8 +120,18 @@ class SimpleHg(simplevcs.SimpleVCS):
         """
         default = 'push'
         batch_cmds = []
+
         try:
-            cmds = cls._get_xarg_headers(environ)
+            httppostargs_enabled = True
+            post_args_size = environ.get('HTTP_X_HGARGS_POST')
+            if post_args_size and httppostargs_enabled:
+                # a new proto when httppostargs is enabled
+                response_data = copy.copy(environ['wsgi.input'])
+                cmds = [safe_str(response_data.read(post_args_size))]
+            else:
+                # old way... from headers
+                cmds = cls._get_xarg_headers(environ)
+
             for pair in cmds:
                 parts = pair.split(' ', 1)
                 if len(parts) != 2: