v 1.2.1

README.md

 
 # Using callbacks
 
-rpclibrary offers a special type of call that can be used with callbacks
+rpclibrary offers a special type of call that can be used with callbacks. The callback *has to be the last argument* and may be the only passed function. 
+
+In order to function, some metadata has to be included in the return value of hooks. On success, the function is expected to return a `type SubscriptionResponse = { result: 'Success', uuid: string }` or in case of errors a `type ErrorResposne = { result: 'Error' }`.
+
+The uuid, as the name implies, is used to uniquely identify the callback for a given invocation and also dictates the name given to the client-side RPC which you should unhook once you're done with it.
 
 ```typescript
 import {Backend, Frontend, Utils} from 'rpclibrary'
         {
             name: 'subscribe',
             hook: async (callback) => {
-                const resp = Utils.makeSubResponse()
+                const resp = Utils.makeSubResponse() //Convenience method to generate SubscriptionResponse
                 callbacks.set(resp.uuid, callback); 
                 return resp
             }
 })
 ```
 
+If you need to include further response data into your `SubscriptionResponse` you can extend it using the server's first generic parameter `SubResType`
+
+```typescript
+new RPCServer<{extension: string}>({
+    exportRPCs: ()  => [
+        {
+            name: 'subscribe',
+            hook: async (callback) => {
+                return {
+                    result: 'Success',
+                    uuid: 'very_random_string',
+                    extension: 'your_data_here'
+                }
+            }
+        }
+    ]
+})
+
+```
+
 #Experimental typing support
-It is possible to declare pseudo-interfaces for servers and clients
+It is possible to declare pseudo-interfaces for servers and clients by using server's second generic parameter.
+This feature is currently still in development and considered **unstable and untested**. Use with caution.
+
 ```typescript
 type MyInterface = RPCInterface<{ 
     Group1: { 
 )
 ```
 
-
-
-
 # Documentation
 [https://gitea.frontblock.me/fw-docs/rpclibrary]

package.json

 {
   "name": "rpclibrary",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "description": "rpclibrary is a websocket on steroids!",
   "main": "./js/Index.js",
   "repository": {

src/Utils.ts

  * Simple utility function to create basic {@link SubscriptionResponse}
  * @param uuid optional uuid to use, otherwise defaults to uuid/v4
  */
-export function makeSubResponse(uuid?:string):SubscriptionResponse{
+export function makeSubResponse<T extends {} = {}>(extension:T):SubscriptionResponse & T{
     return {
         result: "Success",
-        uuid: uuid?uuid:uuidv4(),
+        uuid: uuidv4(),
+        ...extension
     }
 }

test/Test.ts

             if(x === 6)
                 done()
             else
-                done(new Error('echo RPC response did not match'))   
+                done(new Error('add RPC response did not match'))   
         })
     })