Structure Data Using properties and additionalProperties

The properties and additionalProperties under an OpenAPI schema directive show as formal object properties and as a dictionary property. If declared under a property or additionalProperties type, then the OpenAPI parser ignores one or the other. The registration process doesn't throw an error.

OpenAPI named properties are properties in Apex with the same name and property data type.

OpenAPI additionalProperties are grouped as the Apex property with name properties and type Map<String, Type>, where Type is the declared additionalProperties type. The Map property type is a collection of key-value pairs.

OpenAPI additionalProperties are always declared as an Apex object map property, even if it could be declared as a standalone Apex Map type. The result is consistently handled named object properties defined together with additionalProperties.

OpenAPI properties and additionalProperties can both be declared under an OpenAPI parameter schema or schema in the definitions section. The OpenAPI parser ignores either properties or additionalProperties if declared as an object property type. An object property type must only define named properties or additionalProperties, but not both. To work around, place the object property definition as a named schema under definitions and reference it by name.

The OpenAPI parser doesn't differentiate between literal declarations or untyped schemas. Declarations like additionalProperties: true, additionalProperties: false, or additionalProperties: {} are interpreted as untyped. Untyped additionalProperties are ignored. There isn't a workaround to define additionalProperties that can be of any type.

Flow doesn't allow access or manipulation of Apex object types with Map properties, but transparently preserves the content when assigned to variables of the same Apex object type. To manipulate map data structure in flow, call an Apex invocable action that can access the map data structure. For an example with External Service maps in action, see Example 9 in External Services OpenAPI 2.0 Schema.

In any external service registration you create in system version 7 and later, you can define a property with a name that begins with a number. When that property is accessed in Flow or Apex code, the encoding process adjusts the name of the property.

{
  "UserAvatarUrls": {
	"type": "object",
	"properties": {
  	  "24x24": {
    	    "type": "string",
    	    "description": "The URL of the user's 24x24 pixel avatar.",
    	    "format": "uri"
  	},
  	  "32x32": {
    	    "type": "string",
    	    "description": "The URL of the user's 32x32 pixel avatar.",
    	    "format": "uri"
  	},
  	  "16x16": {
    	    "type": "string",
    	    "description": "The URL of the user's 16x16 pixel avatar.",
    	    "format": "uri"
  	},
  	  "48x48": {
    	    "type": "string",
    	    "description": "The URL of the user's 48x48 pixel avatar.",
    	    "format": "uri"
  	}
    }
  }
}