{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "error.schema.json",
  "title": "tar.a2a error",
  "description": "JSON-only error body for protocol tar.a2a version 1.0. Always {error:{code,message}}.",
  "type": "object",
  "additionalProperties": true,
  "required": ["error"],
  "properties": {
    "error": {
      "type": "object",
      "additionalProperties": true,
      "required": ["code", "message"],
      "properties": {
        "code": {
          "type": "string",
          "minLength": 1,
          "description": "Machine-readable slug, e.g. conflict, not_found, validation_error, unauthorized."
        },
        "message": {
          "type": "string",
          "description": "Human-readable explanation. Never includes private keys."
        }
      }
    }
  }
}