core-lightning/doc/schemas/ping.schema.json

{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "type": "object",
    "additionalProperties": false,
    "required": [ "totlen" ],
    "properties": {
	"totlen": {
	    "type": "u16",
	    "description": "the answer length of the reply message (including header: 0 means no reply expected)"
	}
    }
}