epoberezkin/ajv

{
  "$schema": "https://json-schema.org/draft/2019-09/schema",
  "$id": "https://json-schema.org/draft/2019-09/meta/format",
  "$vocabulary": {
    "https://json-schema.org/draft/2019-09/vocab/format": true
  },
  "$recursiveAnchor": true,

  "title": "Format vocabulary meta-schema",
  "type": ["object", "boolean"],
  "properties": {
    "format": {"type": "string"}
  }
}