{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "additionalProperties": false,
  "required": ["status", "filename", "reason"],
  "properties": {
    "status": { "type": "string", "enum": ["ok", "failed"] },
    "filename": { "type": ["string", "null"] },
    "reason": { "type": ["string", "null"] }
  }
}