HTTPResponseError class is no longer exported, and HTTPResponseError.isHTTPResponseError(error) is replaced by isHTTPResponseError(error).got library.got library is replaced with node-fetch.fetch function when creating a Client instance. The client will use this fetch function for all HTTP requests.isNotionClientError type guard, both error.name and error.code are enumerated unions that can be used to further refine the type of error.error.code is guaranteed to be in your library's APIErrorCode or ClientErrorCode enum types, even if the API returns a new, unknown code in a response. In this case, error.code will be ClientErrorCode.ResponseError.Fetched April 3, 2026