diff --git a/oauth2cli/http.py b/oauth2cli/http.py
new file mode 100644
index 00000000..6284c9aa
--- /dev/null
+++ b/oauth2cli/http.py
@@ -0,0 +1,60 @@
+"""This module documents the minimal http behaviors used by this package.
+
+Its interface is influenced by, and similar to a subset of some popular,
+real-world http libraries, such as requests, aiohttp and httpx.
+"""
+
+
+class HttpClient(object):
+    """This describes a minimal http request interface used by this package."""
+
+    def post(self, url, params=None, data=None, headers=None, **kwargs):
+        """HTTP post.
+
+        params, data and headers MUST accept a dictionary.
+        It returns an :class:`~Response`-like object.
+
+        Note: In its async counterpart, this method would be defined as async.
+        """
+        return Response()
+
+    def get(self, url, params=None, headers=None, **kwargs):
+        """HTTP get.
+
+        params, data and headers MUST accept a dictionary.
+        It returns an :class:`~Response`-like object.
+
+        Note: In its async counterpart, this method would be defined as async.
+        """
+        return Response()
+
+
+class Response(object):
+    """This describes a minimal http response interface used by this package.
+
+    :var int status_code:
+        The status code of this http response.
+
+        Our async code path would also accept an alias as "status".
+
+    :var string text:
+        The body of this http response.
+
+        Our async code path would also accept an awaitable with the same name.
+    """
+    status_code = 200  # Our async code path would also accept a name as "status"
+
+    text = "body as a string"  # Our async code path would also accept an awaitable
+        # We could define a json() method instead of a text property/method,
+        # but a `text` would be more generic,
+        # when downstream packages would potentially access some XML endpoints.
+
+    def raise_for_status(self):
+        """Raise an exception when http response status contains error"""
+        raise NotImplementedError("Your implementation should provide this")
+
+
+def _get_status_code(resp):
+    # RFC defines and some libraries use "status_code", others use "status"
+    return getattr(resp, "status_code", None) or resp.status
+