Function httpRefusal

packages/plugins/mcp/src/sdk/invoke.ts:172–181

(
  status: number | undefined,
  cause: unknown,
)

 *  — not a dead transport. 401/403 keep their auth classification; 5xx and
 *  bodyless 4xx stay opaque, since there is nothing the caller can act on. */
const httpRefusal = (
  status: number | undefined,
  cause: unknown,
): { readonly httpRefusal: { readonly status: number; readonly message: string } } | {} => {
  if (status === undefined || status < 400 || status >= 500 || status === 401 || status === 403) {
    return {};
  }
  const message = httpRefusalMessageFromCause(cause);
  return message === undefined ? {} : { httpRefusal: { status, message } };
};

const asProtocolError = (cause: unknown): ProtocolError | undefined => {
  const sdk = mcpClientSdkIfLoaded();