diff --git a/README.md b/README.md
index e1d9d36..ec54111 100644
--- a/README.md
+++ b/README.md
@@ -16,8 +16,8 @@ locks's state in the room.
 The python script polls the broadcast state and pushes changes to Twitter,
 Mastodon and our API file.
 
-The API file is just that, a JSON file. It contains, among other things, the
-current state of the door lock.
+The API file follows the [Space API](http://spaceapi.net) specification, which
+includes a field indicating whether the space is open or closed.
 
 ## Arduino