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)"
    }
  }
}