We are in the process of moving this xApp writing guide to https://docs.o-ran-sc.org.

Please refer to App Writing Guide for latest guide.

JSON schema is used to describe the attributes and values in the xApp descriptor JSON file. The xApp onboarding process verifies the types and values of the xApp parameters in the descriptor.

If mismatches are found, xApp onboarding will return failure.

The schema file consists of two parts: sections that are static and cannot be changed for different xApp, and xApp specific controls section.

When an operator is onboarding an xApp that defines a control section, he/she will provide the controls section schema with together with the xApp descriptor.

The xapp_onboarder will combine the schema files into one.

How to Create Schema for the Controls Section

You can submit arbitrary schema for the controls section. However, if the xApp descriptor contains a controls section, you have to provide the correct schema that describes it.

If the xApp does not require a control section, you can ignore the control section schema.

It is highly recommended to use draft-07 schema. The following is a skeleton schema that you can use

{
	"$schema": "http://json-schema.org/draft-07/schema#",
	"$id": "#/controls",
	"type": "object",
	"title": "Controls Section Schema",
	"required": [
		"REQUIRED_ITEM_1",
		"REQUIRED_ITEM_2"
	],
	"properties": {
		"REQUIRED_ITEM_1": {REQUIRED_ITEM_1_SUB_SCHEMA},
		"REQUIRED_ITEM_2": {REQUIRED_ITEM_2_SUB_SCHEMA}
	}
}

Please include the list of required items in the required section, and provide the corresponding sub_schema in the properties section.

You can download the skeleton schema file here  

xApp Descriptor Schema

The overall schema file includes the following sections.