{
  "type": "object",
  "properties": {
    "project_key": {
      "type": "string",
      "pattern": "[A-Z]+"
    },
    "summary": {
      "type": "string"
    },
    "additional_fields": {
      "anyOf": [
        { "type": "object" },
        { "type": "string" },
        { "type": "null" }
      ]
    }
  },
  "required": ["project_key", "summary"]
}