diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -24,6 +24,12 @@ npm install pipboylib
 
 In order for the utilities provided here to work, you'll need a running Fallout 4 game with the pip-boy app enabled. In order to do the full relay, you'll also want the mobile app running.
 
+## Documentation
+
+As we figure out the spec we'll document what we can over in [docs](docs):
+
+* [App to Server Message Spec](docs/app-msg-spec.md)
+
 ## TODO
 
 * [X] UDP Autodiscovery of PS4 pip boy servers on PS4 [Bronze]
diff --git a/docs/app-msg-spec.md b/docs/app-msg-spec.md
new file mode 100644
index 0000000..d76e2d3
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+++ b/docs/app-msg-spec.md
@@ -0,0 +1,130 @@
+# App to Console structure
+
+TCP messages from the app to the console are ASCII encoded JSON strings of the form:
+
+```
+{"type":<int>,"args":<any[]>,"id":<int>}
+```
+
+An example of this:  
+
+```json
+{"type":6,"args":[-71774.303255814,87841.2072351421,false],"id":11}
+```
+
+It appears that the app sends the console messages twice.  It's unknown if this
+is intentional or not.
+
+## Arguments
+### type
+
+**integer** used to represent the type of the message
+
+### args
+
+**array** array of arguments, of any type, to pass to the handler
+
+### id
+
+**integer** starting at 1 and incrementing by one for each message sent
+
+
+## Oddities
+
+Sometimes the JSON messages are prefixed with some binary data.  An example of
+this follows:
+
+```json
+0x22 0x00 0x00 0x00 0x05 {"type":12,"args":[50308],"id":34}
+```
+
+### Theory A
+`0x22000000` is little-endian `34`, which is the length of the ASCII contents that follows the binary 
+contents.  `0x05` is 5, which seems to be a type/id.
+
+
+# Messages
+Messages are by their **id** and nickname below.
+
+## **6**: Set waypoint 
+
+Sets a waypoint on the world map.
+
+### args
+- *longitude?* **double**  
+- *latitude?* **double**  
+- *?* **boolean**  
+
+### Example
+
+```json
+{"type":6,"args":[-71774.303255814,87841.2072351421,false],"id":11}
+```
+
+
+## **9**: Fast travel
+
+Fast travel to a location
+
+### args
+- *locationId* **integer**  
+
+### Example
+
+```json
+{"type":9,"args":[48363],"id":15}
+```
+
+
+## **13**: Toggle local map view
+
+Changes the map to/from world view from/to local view
+
+### args
+none
+
+### Example
+
+```json
+{"type":13,"args":[],"id":18}
+```
+
+
+## **12**: Toggle a radio station
+
+Toggles a radio station
+
+### args
+- *ID* **integer**  Station ID  
+
+### Known station IDs
+
+ID    | Name
+----- | -------------
+50313 | Diamond city
+50308 | Classical
+
+### Example
+
+```json
+{"type":12,"args":[50308],"id":34}
+```
+
+
+## **1**: Drop item
+
+Drop an item from the player's inventory
+
+### args
+- *?* **integer**  
+- *pageIndex?* **integer**  
+- *?* **integer**  
+- *items?* **integer[]**  
+
+### Example
+
+The following is an example of the item at index 0, a fedora, inside the apparel page (page index 1), getting dropped:  
+
+```json
+{"type":1,"args":[4207600413,1,0,[0]],"id":56}
+```