diff --git a/README.md b/README.md
index 3d0e440..426f758 100644
--- a/README.md
+++ b/README.md
@@ -17,3 +17,10 @@ excellent.
 
 Install elixir and its build tool `mix` through your operating system's package
 manager, then run `mix run`.
+
+After the program starts, it will start listening for clients on port 8080.
+You can connect with netcat or telnet, I haven't yet built a client for this.
+There is no special protocol, the server simply broadcasts whatever you type
+(it waits until you finish a full line).
+
+Building a client is left as an exercise for the reader