{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://kebab.local/wire-schema/v1/error.schema.json",
  "title": "error.v1",
  "description": "Structured fatal error emitted on stderr in --json mode. The `details` shape varies per `code`; consumers should branch on `code` and treat `details` as best-effort context.",
  "type": "object",
  "required": ["schema_version", "code", "message", "details"],
  "properties": {
    "schema_version": { "const": "error.v1" },
    "code": {
      "type": "string",
      "enum": [
        "config_invalid",
        "not_indexed",
        "model_unreachable",
        "model_not_pulled",
        "timeout",
        "io_error",
        "generic",
        "multi_hop_decompose_failed",
        "nli_verification_failed",
        "nli_model_unavailable"
      ]
    },
    "message": { "type": "string" },
    "details": {
      "type": "object",
      "additionalProperties": true,
      "description": "Per-code free-form context. config_invalid: { path, cause }. not_indexed: { expected, found }. model_unreachable: { endpoint, source }. model_not_pulled: { model }. timeout: { source }. io_error: { kind }. generic: { chain (when --verbose) }. multi_hop_decompose_failed: {} (reserved — currently emitted as Answer.refusal_reason on stdout, NOT as error.v1 on stderr; the enum member is forward-looking for a future RefusalReason → error_wire promotion). nli_verification_failed: {} (p9-fb-41 PR-9c-1 reserved — currently emitted only as Answer.refusal_reason on stdout; forward-looking for future RefusalReason → error_wire promotion). nli_model_unavailable: {} (p9-fb-41 PR-9c-1 reserved — same pattern as nli_verification_failed)."
    },
    "hint": {
      "anyOf": [
        { "type": "string" },
        { "type": "null" }
      ]
    }
  }
}