diff --git a/src/tapir.md b/src/tapir.md
index ecb135f..a2d0002 100644
--- a/src/tapir.md
+++ b/src/tapir.md
@@ -19,6 +19,34 @@ together, e.g. authentication depends on a shared cryptographic transcript
 , and the main [cwtch](./cwtch.md) peer app is based on the authentication
 application.
 
+
+## Applications
+
+### Transcript App
+
+**Dependencies:** None
+
+Initializes a [Merlin](https://merlin.cool)-based cryptographic transcript that
+ can be used as the basis of higher level commitment-based protocols
+ 
+ Transcript app will panic if an app ever tries to overwrite an existing
+  transcript with a new one (enforcing the rule that a session is based on
+  one, and only one, transcript.)
+
+### Authentication App
+
+**Dependencies:** Transcript App
+
+Engages in an ephemeral triple-diffie-hellman handshake to derive a unique,
+authenticated session key.
+
+### Token App
+
+**Dependencies:** Transcript App
+
+Allows the client to obtain signed, blinded tokens for use in another
+ application.
+
 ## Known Risks  
 
 ### Impersonation of Peers