RPC protocol for apps

[ir4y]

Problem I need to solve

The new way to extend Aidbox is RPC.
However, the current implementation of the app protocol supports subscription and operations only.
An ability to define RPC on the app side is required.

Solution I see

A user should be able to define a RPC that uses the app as a source.

my-app-rpc
 {:zen/tags #{zenbox/rpc zen/schema}
  :engine  aidbox.rpc/app
  :app my-app-name
  :params {:type zen/map
           :keys {:search {:type zen/string}}}

When this rpc is called aidbox should call app with type rpc.

Reach: Low
Impact: Medium
Effort: Low
Confidence: High