Update README.md

README.md

@@ -434,7 +434,7 @@ $ curl localhost:10000/accounts/retail/central-store
 }
 ~~~
 
-##### Events Persists
+##### Events Persist
 
 If the glngn server application was to be restarted then this data would persist. If the counter
 was queried after restart the value would be the same as before. 
@@ -459,7 +459,38 @@ events to enable your business to start building a model.
 TODO:
 
 1. demo capturing unmodeled events:
-    1. deployment-wide (?)
+    1. deployment-wide
     2. group events
     3. service events
 2. demo capturing a service modeled event
+
+#### Requests
+
+A request is a unique interaction with a client. Requests are implicitly
+created when the endpoints are used. A request can be explicitly requested
+by posting an event of type `command` or `query` to the `_ops` endpoints.
+
+TODO:
+
+1. Each request has a unique ID
+2. Any event may be associated with a request
+3. A request is resolved when a required event is provided
+4. Events may still be associated with a request after resolution
+
+#### Event History
+
+All services have an event history.
+
+TODO:
+
+1. demo querying service history
+
+#### Request History
+
+Each request has an event history.
+
+TODO:
+
+1. demo querying request history
+
+