The following schema describes the JSON data structure for a request from the client for an action from ISPF:

{
  "ACTION":{
    "description":"An action request from the client - ATTN=attention
    interrupt request, EXIT=request to exit one or more ISPF screens,
    FORCETERM=terminate ISPF",
    "type":"string",
    "enum":["ATTN","EXIT","FORCETERM"],
    "required":true
  },
  "SCR":{
    "description":"For an EXIT action request, a list of identifiers for each ISPF
    logical screen to be exited",
    "type":"array",
    "items":{
      "description":"The identifier for the ISPF logical screen to be exited",
      "type":"string",
      "maxLength":1
    }
  }
}