Errors

Undici exposes a variety of error objects that you can use to enhance your error handling. You can find all the error objects inside the errors key.

import { errors } from 'undici'

Error	Error Codes	Description
UndiciError	UND_ERR	all errors below are extended from UndiciError.
ConnectTimeoutError	UND_ERR_CONNECT_TIMEOUT	socket is destroyed due to connect timeout.
HeadersTimeoutError	UND_ERR_HEADERS_TIMEOUT	socket is destroyed due to headers timeout.
HeadersOverflowError	UND_ERR_HEADERS_OVERFLOW	socket is destroyed due to headers' max size being exceeded.
BodyTimeoutError	UND_ERR_BODY_TIMEOUT	socket is destroyed due to body timeout.
ResponseStatusCodeError	UND_ERR_RESPONSE_STATUS_CODE	an error is thrown when throwOnError is true for status codes >= 400.
InvalidArgumentError	UND_ERR_INVALID_ARG	passed an invalid argument.
InvalidReturnValueError	UND_ERR_INVALID_RETURN_VALUE	returned an invalid value.
RequestAbortedError	UND_ERR_ABORTED	the request has been aborted by the user
ClientDestroyedError	UND_ERR_DESTROYED	trying to use a destroyed client.
ClientClosedError	UND_ERR_CLOSED	trying to use a closed client.
SocketError	UND_ERR_SOCKET	there is an error with the socket.
NotSupportedError	UND_ERR_NOT_SUPPORTED	encountered unsupported functionality.
RequestContentLengthMismatchError	UND_ERR_REQ_CONTENT_LENGTH_MISMATCH	request body does not match content-length header
ResponseContentLengthMismatchError	UND_ERR_RES_CONTENT_LENGTH_MISMATCH	response body does not match content-length header
InformationalError	UND_ERR_INFO	expected error with reason
ResponseExceededMaxSizeError	UND_ERR_RES_EXCEEDED_MAX_SIZE	response body exceed the max size allowed
SecureProxyConnectionError	UND_ERR_PRX_TLS	tls connection to a proxy failed

Be aware of the possible difference between the global dispatcher version and the actual undici version you might be using. We recommend to avoid the check instanceof errors.UndiciError and seek for the error.code === '<error_code>' instead to avoid inconsistencies.

SocketError

The SocketError has a .socket property which holds socket metadata:

interface SocketInfo {
  localAddress?: string
  localPort?: number
  remoteAddress?: string
  remotePort?: number
  remoteFamily?: string
  timeout?: number
  bytesWritten?: number
  bytesRead?: number
}

Be aware that in some cases the .socket property can be null.