diff --git a/source/_includes/asides/developers_navigation.html b/source/_includes/asides/developers_navigation.html
index 154e405eac2..531f8935388 100644
--- a/source/_includes/asides/developers_navigation.html
+++ b/source/_includes/asides/developers_navigation.html
@@ -62,6 +62,7 @@
         API
         <ul>
           <li>{% active_link https://dev-docs.home-assistant.io/en/dev/ Home Assistant API %}</li>
+          <li>{% active_link /developers/websocket_api/ Websocket API %}</li>
           <li>{% active_link /developers/rest_api/ RESTful API %}</li>
           <li>{% active_link /developers/python_api/ Python API %}</li>
           <li>{% active_link /developers/server_sent_events/ Server-sent events %}</li>
diff --git a/source/developers/websocket_api.markdown b/source/developers/websocket_api.markdown
new file mode 100644
index 00000000000..faf8bb93455
--- /dev/null
+++ b/source/developers/websocket_api.markdown
@@ -0,0 +1,353 @@
+---
+layout: page
+title: "Websocket API"
+description: "Home Assistant Websocket API documentation"
+date: 2016-11-26 13:27
+sidebar: true
+comments: false
+sharing: true
+footer: true
+---
+
+Home Assistant contains a websocket API. This API can be used to stream information from the Home Assistant server to any client that implements websockets. Implementations in different languages:
+
+ - [JavaScript](https://github.com/home-assistant/home-assistant-js-websocket) - powers the frontend
+
+# Server states
+
+ 1. Client connects
+ 2. Authentication phase starts
+    a. If no further authentication necessary for the user: go to 3
+    b. Server sends `auth_required` message
+    c. Client sends `auth` message
+    d. If `auth` message correct: go to 3.
+    e. Server sends `auth_invalid`. Go to 6.
+ 3. Send `auth_ok` message
+ 4. Authentication phase ends.
+ 5. Command phase starts.
+    a. Client can send commands.
+    b. Server can send results of previous commands.
+ 6. Client or server disconnects session.
+
+During the command phase, the client attaches a unique identifier to each message. The server will add this identifier to each message so that the client can link each message to it's origin.
+
+# Message format
+
+Each API message is a JSON serialized object containing a `type` key. After the authentication phase messages also must contain an `id`, an integer that contains the number of interactions.
+
+Example of an auth message:
+
+```json5
+{
+  "type": "auth",
+  "api_password": "supersecret"
+}
+```
+
+```json5
+{
+   "id" 5,
+   "type":"event",
+   "event":{
+      "data":{},
+      "event_type":"test_event",
+      "time_fired":"2016-11-26T01:37:24.265429+00:00",
+      "origin":"LOCAL"
+   }
+}
+```
+
+# Authentication phase
+
+When a client connects to the server, the server will test if the client is authenticated. Authentication will not be necessary if no api_password is set or if the user fulfills one of the other criteria for authentication (trusted network, password in url/header).
+
+If no authentication is needed, the authentication phase will complete and the server will send an `auth_ok` message.
+
+```json5
+{
+  "type": "auth_ok"
+}
+```
+
+If authentication is necessary, the server sends out `auth_required`.
+
+```json5
+{
+  "type": "auth_required"
+}
+```
+
+This means that the next message from the client should be an auth message:
+
+```json5
+{
+  "type": "auth",
+  "api_password": "supersecret"
+}
+```
+
+If the client supplies valid authentication, the authentication phase will complete by the server sending the `auth_ok` message:
+
+```json5
+{
+  "type": "auth_ok"
+}
+```
+
+If the data is incorrect, the server will reply with `auth_invalid` message and disconnect the session.
+
+```json5
+{
+  "type": "auth_invalid",
+  "message": "Invalid password"
+}
+```
+
+# Command phase
+
+During this phase the client can give commands to the server. The server will respond to each command with a `result` message indicating when the command is done and if it was successful.
+
+```json5
+{
+  "id": 6.
+  "type": "result",
+  "success": true,
+  // Can contain extra result info
+  "result": null
+}
+```
+
+## Subscribe to events
+
+The command `subscribe_events` will subscribe your client to the event bus. You can either listen to all events or to a specific event type. If you want to listen to multiple event types, you will have to send multiple `subscribe_events` commands.
+
+```json5
+{
+  "id": 18,
+  "type": "subscribe_events",
+  // Optional
+  "event_type": "state_changed"
+}
+```
+
+The server will respond with a result message to indicate that the subscription is active.
+
+```json5
+{
+  "id": 18,
+  "type": "result",
+  "success": true,
+  "result": null
+}
+```
+
+For each event that matches, the server will send a message of type `event`. The `id` in the message will point at the original `id` of the `listen_event` command.
+
+```json5
+{
+   "id": 18,
+   "type":"event",
+   "event":{
+      "data":{
+         "entity_id":"light.bed_light",
+         "new_state":{
+            "entity_id":"light.bed_light",
+            "last_changed":"2016-11-26T01:37:24.265390+00:00",
+            "state":"on",
+            "attributes":{
+               "rgb_color":[
+                  254,
+                  208,
+                  0
+               ],
+               "color_temp":380,
+               "supported_features":147,
+               "xy_color":[
+                  0.5,
+                  0.5
+               ],
+               "brightness":180,
+               "white_value":200,
+               "friendly_name":"Bed Light"
+            },
+            "last_updated":"2016-11-26T01:37:24.265390+00:00"
+         },
+         "old_state":{
+            "entity_id":"light.bed_light",
+            "last_changed":"2016-11-26T01:37:10.466994+00:00",
+            "state":"off",
+            "attributes":{
+               "supported_features":147,
+               "friendly_name":"Bed Light"
+            },
+            "last_updated":"2016-11-26T01:37:10.466994+00:00"
+         }
+      },
+      "event_type":"state_changed",
+      "time_fired":"2016-11-26T01:37:24.265429+00:00",
+      "origin":"LOCAL"
+   }
+}
+```
+
+## Unsubscribing from events
+
+You can unsubscribe from previously created subscription events. Pass the id of the original subscription command as value to the subscription field.
+
+```json5
+{
+  "id": 19,
+  "type": "unsubscribe_events",
+  "subscription": 18
+}
+```
+
+The server will respond with a result message to indicate that unsubscribing was successful.
+
+```json5
+{
+  "id": 19,
+  "type": "result",
+  "success": true,
+  "result": null
+}
+```
+
+
+## Calling a service
+
+This will call a service in Home Assistant. Right now there is no return value. The client can listen to `state_changed` events if it is interested in changed entities as a result of a service call.
+
+```json5
+{
+  "id": 24,
+  "type": "call_service",
+  "domain": "light",
+  "service": "turn_on",
+  // Optional
+  "service_data": {
+    "entity_id": "light.kitchen"
+  }
+}
+```
+
+The server will indicate with a message indicating that the service is done executing.
+
+```json5
+{
+  "id": 24,
+  "type": "result",
+  "success": true,
+  "result": null
+}
+```
+
+## Fetching states
+
+This will get a dump of all the current states in Home Assistant.
+
+```json5
+{
+  "id": 19,
+  "type": "get_states"
+}
+```
+
+The server will respond with a result message containing the states.
+
+```json5
+{
+  "id": 19,
+  "type": "result",
+  "success": true,
+  "result": [ … ]
+}
+```
+
+## Fetching config
+
+This will get a dump of the current config in Home Assistant.
+
+```json5
+{
+  "id": 19,
+  "type": "get_config"
+}
+```
+
+The server will respond with a result message containing the config.
+
+```json5
+{
+  "id": 19,
+  "type": "result",
+  "success": true,
+  "result": { … }
+}
+```
+
+## Fetching services
+
+This will get a dump of the current services in Home Assistant.
+
+```json5
+{
+  "id": 19,
+  "type": "get_config"
+}
+```
+
+The server will respond with a result message containing the services.
+
+```json5
+{
+  "id": 19,
+  "type": "result",
+  "success": true,
+  "result": { … }
+}
+```
+
+## Fetching panels
+
+This will get a dump of the current registered panels in Home Assistant.
+
+```json5
+{
+  "id": 19,
+  "type": "get_panels"
+}
+```
+
+The server will respond with a result message containing the current registered panels.
+
+```json5
+{
+  "id": 19,
+  "type": "result",
+  "success": true,
+  "result": [ … ]
+}
+```
+
+# Error handling
+
+If an error occurs, the `success` key in the `result` message will be set to `false`. It will contain an `error` key containing an object with two keys: `code` and `message`.
+
+| Code | Description |
+| ----- | ------------ |
+| 1 | A non-increasing identifier has been supplied.
+| 2 | Received message is not in expected format (voluptuous validation error).
+| 3 | Requested item cannot be found
+
+```json5
+{
+   "id": 12,
+   "type":"result",
+   "success": false,
+   "error": {
+      "code": 2,
+      "message": "Message incorrectly formatted: expected str for dictionary value @ data['event_type']. Got 100"
+   }
+}
+```