diff --git a/README.md b/README.md
index 33ea08f..44a14e3 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,10 @@
 This package provides support for bi-directional communication through
 Server Sent Events and corresponding POST requests.
+
+This package is not intended to be a general purpose SSE package, but instead
+is a bidirectional protocol for use when Websockets are unavailable.
+That is, both the client and the server expose a `sink` and `stream` on which to send
+and receive messages respectively.
+
+Both the server and client have implicit assumptions on each other and therefore a
+client from this package must be paired with a server from this package.