diff --git a/CHANGELOG.md b/CHANGELOG.md
index d2afa6e25..f1adad311 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+# HEAD
+- Add support for attach API calls #180
+
 # v2.0.0a1
 - Update to kubernetes 1.6 spec #169
 
diff --git a/README.md b/README.md
index 09f01cc79..93903ed30 100644
--- a/README.md
+++ b/README.md
@@ -75,6 +75,43 @@ python -m examples.example1
 
 All APIs and Models' documentation can be found at the [Generated client's README file](kubernetes/README.md)
 
+## Compatibility
+
+`client-python` follows [semver](http://semver.org/), so until the major version of
+client-python gets increased, your code will continue to work with explicitly 
+supported versions of Kubernetes clusters.
+
+#### Compatibility matrix
+
+|                         | Kubernetes 1.3 | Kubernetes 1.4 | Kubernetes 1.5 | Kubernetes 1.6 |
+|-------------------------|----------------|----------------|----------------|----------------|
+| client-python 1.0       | +              | +              | ✓              | -              |
+| client-python 2.0 alpha | +              | +              | +              | ✓              |
+| client-python HEAD      | +              | +              | +              | +              |
+
+Key:
+
+* `✓` Exactly the same features / API objects in both client-python and the Kubernetes
+  version.
+* `+` client-python has features or api objects that may not be present in the
+  Kubernetes cluster, but everything they have in common will work.
+* `-` The Kubernetes cluster has features the client-python library can't use
+  (additional API objects, etc).
+
+See the [CHANGELOG](./CHANGELOG.md) for a detailed description of changes
+between client-python versions.
+
+| Client version | Canonical source for OpenAPI spec    | Maintenance status            |
+|----------------|--------------------------------------|-------------------------------|
+| 1.0 Alpha/Beta | Kubernetes main repo, 1.5 branch     | ✗                             |
+| 1.0.x          | Kubernetes main repo, 1.5 branch     | ✓                             |
+| 2.0 alpha      | Kubernetes main repo, 1.6 branch     | ✓                             |
+
+Key:
+
+* `✓` Changes in main Kubernetes repo are manually ([should be automated](https://github.com/kubernetes-incubator/client-python/issues/177)) published to client-python when they are available.
+* `✗` No longer maintained; please upgrade.
+
 ## Community, Support, Discussion
 
 You can reach the maintainers of this project at [SIG API Machinery](https://github.com/kubernetes/community/tree/master/sig-api-machinery). If you have any problem with the package or any suggestions, please file an [issue](https://github.com/kubernetes-incubator/client-python/issues).
diff --git a/kubernetes/client/api_client.py b/kubernetes/client/api_client.py
index 6970ee36d..0e5e14abc 100644
--- a/kubernetes/client/api_client.py
+++ b/kubernetes/client/api_client.py
@@ -346,7 +346,7 @@ class ApiClient(object):
         """
         # FIXME(dims) : We need a better way to figure out which
         # calls end up using web sockets
-        if url.endswith('/exec') and (method == "GET" or method == "POST"):
+        if (url.endswith('/exec') or url.endswith('/attach')) and (method == "GET" or method == "POST"):
             return ws_client.websocket_call(self.config,
                                             url,
                                             query_params=query_params,
diff --git a/kubernetes/client/ws_client.py b/kubernetes/client/ws_client.py
index 7177e5eb2..d29036c82 100644
--- a/kubernetes/client/ws_client.py
+++ b/kubernetes/client/ws_client.py
@@ -234,7 +234,7 @@ def websocket_call(configuration, url, query_params, _request_timeout,
     if isinstance(commands, list):
         for command in commands:
             url += "&command=%s&" % quote_plus(command)
-    else:
+    elif commands is not None:
         url += '&command=' + quote_plus(commands)
 
     try: