# node-http-status

**Reference:**  

- https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml
- https://tools.ietf.org/html/rfc2324#section-2.3.2

## Classes

The first digit of the status-code defines the class of response. The last two digits do not have any categorization role. There are five values for the first digit:

    classes =

1xx - The 1xx (Informational) class of status code indicates an interim response for communicating connection status or request progress prior to completing the requested action and sending a final response.

      '1xx': 'Informational'
      '1xx_NAME': 'INFORMATIONAL'
      '1xx_MESSAGE': 'Indicates an interim response for communicating connection status or request progress prior to completing the requested action and sending a final response.'
      INFORMATIONAL: '1xx'

2xx - The 2xx (Successful) class of status code indicates that the client's request was successfully received, understood, and accepted.

      '2xx': 'Successful'
      '2xx_NAME': 'SUCCESSFUL'
      '2xx_MESSAGE': 'Indicates that the client\'s request was successfully received, understood, and accepted.'
      SUCCESSFUL: '2xx'

3xx - The 3xx (Redirection) class of status code indicates that further action needs to be taken by the user agent in order to fulfill the request.

      '3xx': 'Redirection'
      '3xx_NAME': 'REDIRECTION'
      '3xx_MESSAGE': 'Indicates that further action needs to be taken by the user agent in order to fulfill the request.'
      REDIRECTION: '3xx'

4xx - The 4xx (Client Error) class of status code indicates that the client seems to have erred.

      '4xx': 'Client Error'
      '4xx_NAME': 'CLIENT_ERROR'
      '4xx_MESSAGE': 'Indicates that the client seems to have erred.'
      CLIENT_ERROR: '4xx'

5xx - The 5xx (Server Error) class of status code indicates that the server is aware that it has erred or is incapable of performing the requested method.

      '5xx': 'Server Error'
      '5xx_NAME': 'SERVER_ERROR'
      '5xx_MESSAGE': 'Indicates that the server is aware that it has erred or is incapable of performing the requested method.'
      SERVER_ERROR: '5xx'

    module.exports =

    classes: classes

## Informational 1xx

Indicates an interim response for communicating connection status or request progress prior to completing the requested action and sending a final response.

100 - The server has received the request headers and the client should proceed to send the request body.

    100: 'Continue'
    '100_NAME': 'CONTINUE'
    '100_MESSAGE': 'The server has received the request headers and the client should proceed to send the request body.'
    '100_CLASS': classes.INFORMATIONAL
    CONTINUE: 100

101 - The requester has asked the server to switch protocols and the server has agreed to do so.

    101: 'Switching Protocols'
    '101_NAME': 'SWITCHING_PROTOCOLS'
    '101_MESSAGE': 'The requester has asked the server to switch protocols and the server has agreed to do so.'
    '101_CLASS': classes.INFORMATIONAL
    SWITCHING_PROTOCOLS: 101

102 Processing (WebDAV; RFC 2518) - A WebDAV request may contain many sub-requests involving file operations, requiring a long time to complete the request. This code indicates that the server has received and is processing the request, but no response is available yet.[7] This prevents the client from timing out and assuming the request was lost.

    102: 'Processing'
    '102_NAME': 'PROCESSING'
    '102_MESSAGE': 'A WebDAV request may contain many sub-requests involving file operations, requiring a long time to complete the request. This code indicates that the server has received and is processing the request, but no response is available yet.[7] This prevents the client from timing out and assuming the request was lost.'
    '102_CLASS': classes.INFORMATIONAL
    PROCESSING: 102

103 Early Hints (RFC 8297) - Used to return some response headers before final HTTP message.

    103: 'Early Hints'
    '103_NAME': 'EARLY_HINTS'
    '103_MESSAGE': 'Used to return some response headers before final HTTP message.'
    '103_CLASS': classes.INFORMATIONAL
    EARLY_HINTS: 103

## Successful 2xx

Indicates that the client's request was successfully received, understood, and accepted.

200 - Standard response for successful HTTP requests.

    200: 'OK'
    '200_NAME': 'OK'
    '200_MESSAGE': 'Standard response for successful HTTP requests.'
    '200_CLASS': classes.SUCCESSFUL
    OK: 200

201 - The request has been fulfilled, resulting in the creation of a new resource.

    201: 'Created'
    '201_NAME': 'CREATED'
    '201_MESSAGE': 'The request has been fulfilled, resulting in the creation of a new resource.'
    '201_CLASS': classes.SUCCESSFUL
    CREATED: 201

202 - The request has been accepted for processing, but the processing has not been completed.

    202: 'Accepted'
    '202_NAME': 'ACCEPTED'
    '202_MESSAGE': 'The request has been accepted for processing, but the processing has not been completed.'
    '202_CLASS': classes.SUCCESSFUL
    ACCEPTED: 202

203 (since HTTP/1.1) - The server is a transforming proxy (e.g. a Web accelerator) that received a 200 OK from its origin, but is returning a modified version of the origin's response.

    203: 'Non-Authoritative Information'
    '203_NAME': 'NON_AUTHORITATIVE_INFORMATION'
    '203_MESSAGE': 'The server is a transforming proxy (e.g. a Web accelerator) that received a 200 OK from its origin, but is returning a modified version of the origin\'s response.'
    '203_CLASS': classes.SUCCESSFUL
    NON_AUTHORITATIVE_INFORMATION: 203

204 - The server successfully processed the request and is not returning any content.

    204: 'No Content'
    '204_NAME': 'NO_CONTENT'
    '204_MESSAGE': 'The server successfully processed the request and is not returning any content.'
    '204_CLASS': classes.SUCCESSFUL
    NO_CONTENT: 204

205 - The server successfully processed the request, but is not returning any content. Unlike a 204 response, this response requires that the requester reset the document view.

    205: 'Reset Content'
    '205_NAME': 'RESET_CONTENT'
    '205_MESSAGE': 'The server successfully processed the request, but is not returning any content. Unlike a 204 response, this response requires that the requester reset the document view.'
    '205_CLASS': classes.SUCCESSFUL
    RESET_CONTENT: 205

206 (RFC 7233) - The server is delivering only part of the resource (byte serving) due to a range header sent by the client.

    206: 'Partial Content'
    '206_NAME': 'PARTIAL_CONTENT'
    '206_MESSAGE': 'The server is delivering only part of the resource (byte serving) due to a range header sent by the client.'
    '206_CLASS': classes.SUCCESSFUL
    PARTIAL_CONTENT: 206

207 (WebDAV; RFC 4918) - The message body that follows is by default an XML message and can contain a number of separate response codes, depending on how many sub-requests were made.

    207: 'Multi Status'
    '207_NAME': 'MULTI_STATUS'
    '207_MESSAGE': 'The message body that follows is by default an XML message and can contain a number of separate response codes, depending on how many sub-requests were made.'
    '207_CLASS': classes.SUCCESSFUL
    MULTI_STATUS: 207

208 (WebDAV; RFC 5842) - The members of a DAV binding have already been enumerated in a preceding part of the (multistatus) response, and are not being included again.

    208: 'Already Reported'
    '208_NAME': 'ALREADY_REPORTED'
    '208_MESSAGE': 'The members of a DAV binding have already been enumerated in a preceding part of the (multistatus) response, and are not being included again.'
    '208_CLASS': classes.SUCCESSFUL
    ALREADY_REPORTED: 208

226 (RFC 3229) - The server has fulfilled a request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance.

    226: 'IM Used'
    '226_NAME': 'IM_USED'
    '226_MESSAGE': 'The server has fulfilled a request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance.'
    '226_CLASS': classes.SUCCESSFUL
    IM_USED: 226

## Redirection 3xx

Indicates that further action needs to be taken by the user agent in order to fulfill the request.

300 - Indicates multiple options for the resource from which the client may choose.

    300: 'Multiple Choices'
    '300_NAME': 'MULTIPLE_CHOICES'
    '300_MESSAGE': 'Indicates multiple options for the resource from which the client may choose.'
    '300_CLASS': classes.REDIRECTION
    MULTIPLE_CHOICES: 300

301 - This and all future requests should be directed to the given URI.

    301: 'Moved Permanently'
    '301_NAME': 'MOVED_PERMANENTLY'
    '301_MESSAGE': 'This and all future requests should be directed to the given URI.'
    '301_CLASS': classes.REDIRECTION
    MOVED_PERMANENTLY: 301

302 - This is an example of industry practice contradicting the standard. The HTTP/1.0 specification (RFC 1945) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"), but popular browsers implemented 302 with the functionality of a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to distinguish between the two behaviours.

    302: 'Found'
    '302_NAME': 'FOUND'
    '302_MESSAGE': 'This is an example of industry practice contradicting the standard. The HTTP/1.0 specification (RFC 1945) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"), but popular browsers implemented 302 with the functionality of a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to distinguish between the two behaviours.'
    '302_CLASS': classes.REDIRECTION
    FOUND: 302

303 (since HTTP/1.1) - The response to the request can be found under another URI using the GET method.

    303: 'See Other'
    '303_NAME': 'SEE_OTHER'
    '303_MESSAGE': 'The response to the request can be found under another URI using the GET method.'
    '303_CLASS': classes.REDIRECTION
    SEE_OTHER: 303

304 (RFC 7232) - Indicates that the resource has not been modified since the version specified by the request headers If-Modified-Since or If-None-Match.

    304: 'Not Modified'
    '304_NAME': 'NOT_MODIFIED'
    '304_MESSAGE': 'Indicates that the resource has not been modified since the version specified by the request headers If-Modified-Since or If-None-Match.'
    '304_CLASS': classes.REDIRECTION
    NOT_MODIFIED: 304

305 (since HTTP/1.1) - The requested resource is available only through a proxy, the address for which is provided in the response.

    305: 'Use Proxy'
    '305_NAME': 'USE_PROXY'
    '305_MESSAGE': 'The requested resource is available only through a proxy, the address for which is provided in the response.'
    '305_CLASS': classes.REDIRECTION
    USE_PROXY: 305

306 - No longer used. Originally meant "Subsequent requests should use the specified proxy.

    306: 'Switch Proxy'
    '306_NAME': 'SWITCH_PROXY'
    '306_MESSAGE': 'No longer used. Originally meant "Subsequent requests should use the specified proxy.'
    '306_CLASS': classes.REDIRECTION
    SWITCH_PROXY: 306

307 (since HTTP/1.1) - In this case, the request should be repeated with another URI; however, future requests should still use the original URI.

    307: 'Temporary Redirect'
    '307_NAME': 'TEMPORARY_REDIRECT'
    '307_MESSAGE': 'In this case, the request should be repeated with another URI; however, future requests should still use the original URI.'
    '307_CLASS': classes.REDIRECTION
    TEMPORARY_REDIRECT: 307

308 (RFC 7538) - The request and all future requests should be repeated using another URI.

    308: 'Permanent Redirect'
    '308_NAME': 'PERMANENT_REDIRECT'
    '308_MESSAGE': 'The request and all future requests should be repeated using another URI.'
    '308_CLASS': classes.REDIRECTION
    PERMANENT_REDIRECT: 308

## Client Error 4xx

Indicates that the client seems to have erred.

400 - The server cannot or will not process the request due to an apparent client error.

    400: 'Bad Request'
    '400_NAME': 'BAD_REQUEST'
    '400_MESSAGE': 'The server cannot or will not process the request due to an apparent client error.'
    '400_CLASS': classes.CLIENT_ERROR
    BAD_REQUEST: 400

401 (RFC 7235) - Similar to 403 Forbidden, but specifically for use when authentication is required and has failed or has not yet been provided.

    401: 'Unauthorized'
    '401_NAME': 'UNAUTHORIZED'
    '401_MESSAGE': 'Similar to 403 Forbidden, but specifically for use when authentication is required and has failed or has not yet been provided.'
    '401_CLASS': classes.CLIENT_ERROR
    UNAUTHORIZED: 401

402 - Reserved for future use. The original intention was that this code might be used as part of some form of digital cash or micropayment scheme, as proposed for example by GNU Taler, but that has not yet happened, and this code is not usually used.

    402: 'Payment Required'
    '402_NAME': 'PAYMENT_REQUIRED'
    '402_MESSAGE': 'Reserved for future use. The original intention was that this code might be used as part of some form of digital cash or micropayment scheme, as proposed for example by GNU Taler, but that has not yet happened, and this code is not usually used.'
    '402_CLASS': classes.CLIENT_ERROR
    PAYMENT_REQUIRED: 402

403 - The request was valid, but the server is refusing action.

    403: 'Forbidden'
    '403_NAME': 'FORBIDDEN'
    '403_MESSAGE': 'The request was valid, but the server is refusing action.'
    '403_CLASS': classes.CLIENT_ERROR
    FORBIDDEN: 403

404 - The requested resource could not be found but may be available in the future. Subsequent requests by the client are permissible.

    404: 'Not Found'
    '404_NAME': 'NOT_FOUND'
    '404_MESSAGE': 'The requested resource could not be found but may be available in the future. Subsequent requests by the client are permissible.'
    '404_CLASS': classes.CLIENT_ERROR
    NOT_FOUND: 404

405 - A request method is not supported for the requested resource.

    405: 'Method Not Allowed'
    '405_NAME': 'METHOD_NOT_ALLOWED'
    '405_MESSAGE': 'A request method is not supported for the requested resource.'
    '405_CLASS': classes.CLIENT_ERROR
    METHOD_NOT_ALLOWED: 405

406 - The requested resource is capable of generating only content not acceptable according to the Accept headers sent in the request.

    406: 'Not Acceptable'
    '406_NAME': 'NOT_ACCEPTABLE'
    '406_MESSAGE': 'The requested resource is capable of generating only content not acceptable according to the Accept headers sent in the request.'
    '406_CLASS': classes.CLIENT_ERROR
    NOT_ACCEPTABLE: 406

407 (RFC 7235) - The client must first authenticate itself with the proxy.

    407: 'Proxy Authentication Required'
    '407_NAME': 'PROXY_AUTHENTICATION_REQUIRED'
    '407_MESSAGE': 'The client must first authenticate itself with the proxy.'
    '407_CLASS': classes.CLIENT_ERROR
    PROXY_AUTHENTICATION_REQUIRED: 407

408 - The server timed out waiting for the request.

    408: 'Request Time-out'
    '408_NAME': 'REQUEST_TIMEOUT'
    '408_MESSAGE': 'The server timed out waiting for the request.'
    '408_CLASS': classes.CLIENT_ERROR
    REQUEST_TIMEOUT: 408

409 - Indicates that the request could not be processed because of conflict in the request, such as an edit conflict between multiple simultaneous updates.

    409: 'Conflict'
    '409_NAME': 'CONFLICT'
    '409_MESSAGE': 'Indicates that the request could not be processed because of conflict in the request, such as an edit conflict between multiple simultaneous updates.'
    '409_CLASS': classes.CLIENT_ERROR
    CONFLICT: 409

410 - Indicates that the resource requested is no longer available and will not be available again.

    410: 'Gone'
    '410_NAME': 'GONE'
    '410_MESSAGE': 'Indicates that the resource requested is no longer available and will not be available again.'
    '410_CLASS': classes.CLIENT_ERROR
    GONE: 410

411 - The request did not specify the length of its content, which is required by the requested resource.

    411: 'Length Required'
    '411_NAME': 'LENGTH_REQUIRED'
    '411_MESSAGE': 'The request did not specify the length of its content, which is required by the requested resource.'
    '411_CLASS': classes.CLIENT_ERROR
    LENGTH_REQUIRED: 411

412 (RFC 7232) - The server does not meet one of the preconditions that the requester put on the request.

    412: 'Precondition Failed'
    '412_NAME': 'PRECONDITION_FAILED'
    '412_MESSAGE': 'The server does not meet one of the preconditions that the requester put on the request.'
    '412_CLASS': classes.CLIENT_ERROR
    PRECONDITION_FAILED: 412

413 (RFC 7231) - The request is larger than the server is willing or able to process. Previously called "Request Entity Too Large".

    413: 'Request Entity Too Large'
    '413_NAME': 'REQUEST_ENTITY_TOO_LARGE'
    '413_MESSAGE': 'The request is larger than the server is willing or able to process. Previously called "Request Entity Too Large".'
    '413_CLASS': classes.CLIENT_ERROR
    REQUEST_ENTITY_TOO_LARGE: 413

414 (RFC 7231) - The URI provided was too long for the server to process.

    414: 'Request-URI Too Large'
    '414_NAME': 'REQUEST_URI_TOO_LONG'
    '414_MESSAGE': 'The URI provided was too long for the server to process.'
    '414_CLASS': classes.CLIENT_ERROR
    REQUEST_URI_TOO_LONG: 414

415 - The request entity has a media type which the server or resource does not support.

    415: 'Unsupported Media Type'
    '415_NAME': 'UNSUPPORTED_MEDIA_TYPE'
    '415_MESSAGE': 'The request entity has a media type which the server or resource does not support.'
    '415_CLASS': classes.CLIENT_ERROR
    UNSUPPORTED_MEDIA_TYPE: 415

416 (RFC 7233) - The client has asked for a portion of the file (byte serving), but the server cannot supply that portion.

    416: 'Requested Range not Satisfiable'
    '416_NAME': 'REQUESTED_RANGE_NOT_SATISFIABLE'
    '416_MESSAGE': 'The client has asked for a portion of the file (byte serving), but the server cannot supply that portion.'
    '416_CLASS': classes.CLIENT_ERROR
    REQUESTED_RANGE_NOT_SATISFIABLE: 416

417 - The server cannot meet the requirements of the Expect request-header field.

    417: 'Expectation Failed'
    '417_NAME': 'EXPECTATION_FAILED'
    '417_MESSAGE': 'The server cannot meet the requirements of the Expect request-header field.'
    '417_CLASS': classes.CLIENT_ERROR
    EXPECTATION_FAILED: 417

418 (RFC 2324, RFC 7168) - Any attempt to brew coffee with a teapot should result in the error code "418 I'm a teapot". The resulting entity body MAY be short and stout. This code was defined in 1998 as one of the traditional IETF April Fools' jokes, in RFC 2324, Hyper Text Coffee Pot Control Protocol, and is not expected to be implemented by actual HTTP servers. The RFC specifies this code should be returned by teapots requested to brew coffee. This HTTP status is used as an Easter egg in some websites, including Google.com.

    418: 'I\'m a teapot'
    '418_NAME': 'IM_A_TEAPOT'
    '418_MESSAGE': 'Any attempt to brew coffee with a teapot should result in the error code "418 I\'m a teapot". The resulting entity body MAY be short and stout.'
    '418_CLASS': classes.CLIENT_ERROR
    IM_A_TEAPOT: 418

421 (RFC 7540) - The request was directed at a server that is not able to produce a response.

    421: 'Misdirected Request'
    '421_NAME': 'MISDIRECTED_REQUEST'
    '421_MESSAGE': 'The request was directed at a server that is not able to produce a response.'
    '421_CLASS': classes.CLIENT_ERROR
    MISDIRECTED_REQUEST: 421

422 (WebDAV; RFC 4918) - The request was well-formed but was unable to be followed due to semantic errors.

    422: 'Unprocessable Entity'
    '422_NAME': 'UNPROCESSABLE_ENTITY'
    '422_MESSAGE': 'The request was well-formed but was unable to be followed due to semantic errors.'
    '422_CLASS': classes.CLIENT_ERROR
    UNPROCESSABLE_ENTITY: 422

423 (WebDAV; RFC 4918) - The resource that is being accessed is locked.

    423: 'Locked'
    '423_NAME': 'LOCKED'
    '423_MESSAGE': 'The resource that is being accessed is locked.'
    '423_CLASS': classes.CLIENT_ERROR
    LOCKED: 423

424 (WebDAV; RFC 4918) - The request failed because it depended on another request and that request failed.

    424: 'Failed Dependency'
    '424_NAME': 'FAILED_DEPENDENCY'
    '424_MESSAGE': 'The request failed because it depended on another request and that request failed.'
    '424_CLASS': classes.CLIENT_ERROR
    FAILED_DEPENDENCY: 424

426 - The client should switch to a different protocol such as TLS/1.0, given in the Upgrade header field.

    426: 'Upgrade Required'
    '426_NAME': 'UPGRADE_REQUIRED'
    '426_MESSAGE': 'The client should switch to a different protocol such as TLS/1.0, given in the Upgrade header field.'
    '426_CLASS': classes.CLIENT_ERROR
    UPGRADE_REQUIRED: 426

428 (RFC 6585) - The origin server requires the request to be conditional.

    428: 'Precondition Required' # RFC 6585
    '428_NAME': 'PRECONDITION_REQUIRED'
    '428_MESSAGE': 'The origin server requires the request to be conditional.'
    '428_CLASS': classes.CLIENT_ERROR
    PRECONDITION_REQUIRED: 428

429 (RFC 6585) - The user has sent too many requests in a given amount of time.

    429: 'Too Many Requests'
    '429_NAME': 'TOO_MANY_REQUESTS'
    '429_MESSAGE': 'The user has sent too many requests in a given amount of time.'
    '429_CLASS': classes.CLIENT_ERROR
    TOO_MANY_REQUESTS: 429

431 (RFC 6585) - The server is unwilling to process the request because either an individual header field, or all the header fields collectively, are too large.

    431: 'Request Header Fields Too Large' # RFC 6585
    '431_NAME': 'REQUEST_HEADER_FIELDS_TOO_LARGE'
    '431_MESSAGE': 'The server is unwilling to process the request because either an individual header field, or all the header fields collectively, are too large.'
    '431_CLASS': classes.CLIENT_ERROR
    REQUEST_HEADER_FIELDS_TOO_LARGE: 431

451 (RFC 7725) - A server operator has received a legal demand to deny access to a resource or to a set of resources that includes the requested resource.

    451: 'Unavailable For Legal Reasons'
    '451_NAME': 'UNAVAILABLE_FOR_LEGAL_REASONS'
    '451_MESSAGE': 'A server operator has received a legal demand to deny access to a resource or to a set of resources that includes the requested resource.'
    '451_CLASS': classes.CLIENT_ERROR
    UNAVAILABLE_FOR_LEGAL_REASONS: 451

## Server Error 5xx

Indicates that the server is aware that it has erred or is incapable of performing the requested method.

500 - A generic error message, given when an unexpected condition was encountered and no more specific message is suitable.

    500: 'Internal Server Error'
    '500_NAME': 'INTERNAL_SERVER_ERROR'
    '500_MESSAGE': 'A generic error message, given when an unexpected condition was encountered and no more specific message is suitable.'
    '500_CLASS': classes.SERVER_ERROR
    INTERNAL_SERVER_ERROR: 500

501 - The server either does not recognize the request method, or it lacks the ability to fulfil the request. Usually this implies future availability.

    501: 'Not Implemented'
    '501_NAME': 'NOT_IMPLEMENTED'
    '501_MESSAGE': 'The server either does not recognize the request method, or it lacks the ability to fulfil the request. Usually this implies future availability.'
    '501_CLASS': classes.SERVER_ERROR
    NOT_IMPLEMENTED: 501

502 - The server was acting as a gateway or proxy and received an invalid response from the upstream server.

    502: 'Bad Gateway'
    '502_NAME': 'BAD_GATEWAY'
    '502_MESSAGE': 'The server was acting as a gateway or proxy and received an invalid response from the upstream server.'
    '502_CLASS': classes.SERVER_ERROR
    BAD_GATEWAY: 502

503 - The server is currently unavailable (because it is overloaded or down for maintenance). Generally, this is a temporary state.

    503: 'Service Unavailable'
    '503_NAME': 'SERVICE_UNAVAILABLE'
    '503_MESSAGE': 'The server is currently unavailable (because it is overloaded or down for maintenance). Generally, this is a temporary state.'
    '503_CLASS': classes.SERVER_ERROR
    SERVICE_UNAVAILABLE: 503

504 - The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.

    504: 'Gateway Time-out'
    '504_NAME': 'GATEWAY_TIMEOUT'
    '504_MESSAGE': 'The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.'
    '504_CLASS': classes.SERVER_ERROR
    GATEWAY_TIMEOUT: 504

505 - The server does not support the HTTP protocol version used in the request.

    505: 'HTTP Version not Supported'
    '505_NAME': 'HTTP_VERSION_NOT_SUPPORTED'
    '505_MESSAGE': 'The server does not support the HTTP protocol version used in the request.'
    '505_CLASS': classes.SERVER_ERROR
    HTTP_VERSION_NOT_SUPPORTED: 505

506 (RFC 2295) - Transparent content negotiation for the request results in a circular reference.

    506: 'Variant Also Negotiates'
    '506_NAME': 'VARIANT_ALSO_NEGOTIATES'
    '506_MESSAGE': 'Transparent content negotiation for the request results in a circular reference.'
    '506_CLASS': classes.SERVER_ERROR
    VARIANT_ALSO_NEGOTIATES: 506

507 (WebDAV; RFC 4918) - The server is unable to store the representation needed to complete the request.

    507: 'Insufficient Storage'
    '507_NAME': 'INSUFFICIENT_STORAGE'
    '507_MESSAGE': 'The server is unable to store the representation needed to complete the request.'
    '507_CLASS': classes.SERVER_ERROR
    INSUFFICIENT_STORAGE: 507

508 (WebDAV; RFC 5842) - The server detected an infinite loop while processing the request.

    508: 'Loop Detected'
    '508_NAME': 'LOOP_DETECTED'
    '508_MESSAGE': 'The server detected an infinite loop while processing the request.'
    '508_CLASS': classes.SERVER_ERROR
    LOOP_DETECTED: 508

510 (RFC 2774) - Further extensions to the request are required for the server to fulfil it.

    510: 'Not Extended'
    '510_NAME': 'NOT_EXTENDED'
    '510_MESSAGE': 'Further extensions to the request are required for the server to fulfil it.'
    '510_CLASS': classes.SERVER_ERROR
    NOT_EXTENDED: 510

511 (RFC 6585) - The client needs to authenticate to gain network access. Intended for use by intercepting proxies used to control access to the network.

    511: 'Network Authentication Required'
    '511_NAME': 'NETWORK_AUTHENTICATION_REQUIRED'
    '511_MESSAGE': 'The client needs to authenticate to gain network access. Intended for use by intercepting proxies used to control access to the network.'
    '511_CLASS': classes.SERVER_ERROR
    NETWORK_AUTHENTICATION_REQUIRED: 511

## Extra code

Extra HTTP code implemented by vendors and other specifications.

    extra:

### Unofficial codes

The following codes are not specified by any standard.

      unofficial:

103 - Used in the resumable requests proposal to resume aborted PUT or POST requests.

        103: 'Checkpoint'
        '103_NAME': 'CHECKPOINT'
        '103_MESSAGE': 'Used in the resumable requests proposal to resume aborted PUT or POST requests.'
        '103_CLASS': classes.INFORMATIONAL
        CHECKPOINT: 103

419 Page Expired (Laravel Framework) - Used by the Laravel Framework when a CSRF Token is missing or expired.

        419: 'Page Expired'
        '419_NAME': 'PAGE_EXPIRED'
        '419_MESSAGE': 'Used by the Laravel Framework when a CSRF Token is missing or expired.'
        '419_CLASS': classes.CLIENT_ERROR
        PAGE_EXPIRED: 419

218 This is fine (Apache Web Server) - Used as a catch-all error condition for allowing response bodies to flow through Apache when ProxyErrorOverride is enabled. When ProxyErrorOverride is enabled in Apache, response bodies that contain a status code of 4xx or 5xx are automatically discarded by Apache in favor of a generic response or a custom response specified by the ErrorDocument directive.

        218: 'This is fine'
        '218_NAME': 'THIS_IS_FINE'
        '218_MESSAGE': 'Used as a catch-all error condition for allowing response bodies to flow through Apache when ProxyErrorOverride is enabled. When ProxyErrorOverride is enabled in Apache, response bodies that contain a status code of 4xx or 5xx are automatically discarded by Apache in favor of a generic response or a custom response specified by the ErrorDocument directive.'
        '218_CLASS': classes.SUCCESSFUL
        THIS_IS_FINE: 218

420 Enhance Your Calm (Twitter) - Returned by version 1 of the Twitter Search and Trends API when the client is being rate limited; versions 1.1 and later use the 429 Too Many Requests response code instead.

        420: 'Enhance Your Calm'
        '420_NAME': 'ENHANCE_YOUR_CALM'
        '420_MESSAGE': 'Returned by version 1 of the Twitter Search and Trends API when the client is being rate limited; versions 1.1 and later use the 429 Too Many Requests response code instead.'
        '420_CLASS': classes.CLIENT_ERROR
        ENHANCE_YOUR_CALM: 420

450 Blocked by Windows Parental (Microsoft) - The Microsoft extension code indicated when Windows Parental Controls are turned on and are blocking access to the requested webpage.

        450: 'Blocked by Windows Parental Controls'
        '450_NAME': 'BLOCKED_BY_WINDOWS_PARENTAL_CONTROLS'
        '450_MESSAGE': 'The Microsoft extension code indicated when Windows Parental Controls are turned on and are blocking access to the requested webpage.'
        '450_CLASS': classes.CLIENT_ERROR
        BLOCKED_BY_WINDOWS_PARENTAL_CONTROLS: 450

498 Invalid Token (Esri) - Returned by ArcGIS for Server. Code 498 indicates an expired or otherwise invalid token.

        498: 'Invalid Token'
        '498_NAME': 'INVALID_TOKEN'
        '498_MESSAGE': 'Returned by ArcGIS for Server. Code 498 indicates an expired or otherwise invalid token.'
        '498_CLASS': classes.CLIENT_ERROR
        INVALID_TOKEN: 498

499 Token Required (Esri) - Returned by ArcGIS for Server. Code 499 indicates that a token is required but was not submitted.

        499: 'Token Required'
        '499_NAME': 'TOKEN_REQUIRED'
        '499_MESSAGE': 'Returned by ArcGIS for Server. Code 499 indicates that a token is required but was not submitted.'
        '499_CLASS': classes.CLIENT_ERROR
        TOKEN_REQUIRED: 499

509 Bandwidth Limit Exceeded (Apache Web Server/cPanel) - The server has exceeded the bandwidth specified by the server administrator.

        509: 'Bandwidth Limit Exceeded'
        '509_NAME': 'BANDWIDTH_LIMIT_EXCEEDED'
        '509_MESSAGE': 'The server has exceeded the bandwidth specified by the server administrator.'
        '509_CLASS': classes.SERVER_ERROR
        BANDWIDTH_LIMIT_EXCEEDED: 509

530 Site is frozen - Used by the Pantheon web platform to indicate a site that has been frozen due to inactivity.

        530: 'Site is frozen'
        '530_NAME': 'SITE_IS_FROZEN'
        '530_MESSAGE': 'Used by the Pantheon web platform to indicate a site that has been frozen due to inactivity.'
        '530_CLASS': classes.SERVER_ERROR
        SITE_IS_FROZEN: 530

598 (Informal convention) Network read timeout error - Used by some HTTP proxies to signal a network read timeout behind the proxy to a client in front of the proxy.

        598: 'Network read timeout error'
        '598_NAME': 'NETWORK_READ_TIMEOUT_ERROR'
        '598_MESSAGE': 'Used by some HTTP proxies to signal a network read timeout behind the proxy to a client in front of the proxy.'
        '598_CLASS': classes.SERVER_ERROR
        NETWORK_READ_TIMEOUT_ERROR: 598

### Internet Information Services (IIS)

Microsoft's Internet Information Services (IIS) web server expands the 4xx error space to signal errors with the client's request.

      iis:

440 - The client's session has expired and must log in again.

        440: 'Login Time-out'
        '440_NAME': 'LOGIN_TIME_OUT'
        '440_MESSAGE': 'The client\'s session has expired and must log in again.'
        '440_CLASS': classes.CLIENT_ERROR
        LOGIN_TIME_OUT: 440

449 - The server cannot honour the request because the user has not provided the required information.

        449: 'Retry With'
        '449_NAME': 'RETRY_WITH'
        '449_MESSAGE': 'The server cannot honour the request because the user has not provided the required information.'
        '449_CLASS': classes.CLIENT_ERROR
        RETRY_WITH: 449

451 - Used in Exchange ActiveSync when either a more efficient server is available or the server cannot access the users' mailbox.

        451: 'Redirect'
        '451_NAME': 'REDIRECT'
        '451_MESSAGE': 'Used in Exchange ActiveSync when either a more efficient server is available or the server cannot access the users\' mailbox.'
        '451_CLASS': classes.CLIENT_ERROR
        REDIRECT: 451

### NGINX

The NGINX web server software expands the 4xx error space to signal issues with the client's request.

      nginx:

444 - Used internally to instruct the server to return no information to the client and close the connection immediately.

        444: 'No Response'
        '444_NAME': 'NO_RESPONSE'
        '444_MESSAGE': 'Used internally to instruct the server to return no information to the client and close the connection immediately.'
        '444_CLASS': classes.CLIENT_ERROR
        NO_RESPONSE: 444

494 - Client sent too large request or too long header line.

        494: 'Request header too large'
        '494_NAME': 'REQUEST_HEADER_TOO_LARGE'
        '494_MESSAGE': 'Client sent too large request or too long header line.'
        '494_CLASS': classes.CLIENT_ERROR
        REQUEST_HEADER_TOO_LARGE: 494

495 - An expansion of the 400 Bad Request response code, used when the client has provided an invalid client certificate.

        495: 'SSL Certificate Error'
        '495_NAME': 'SSL_CERTIFICATE_ERROR'
        '495_MESSAGE': 'An expansion of the 400 Bad Request response code, used when the client has provided an invalid client certificate.'
        '495_CLASS': classes.CLIENT_ERROR
        SSL_CERTIFICATE_ERROR: 495

496 - An expansion of the 400 Bad Request response code, used when a client certificate is required but not provided.

        496: 'SSL Certificate Required'
        '496_NAME': 'SSL_CERTIFICATE_REQUIRED'
        '496_MESSAGE': 'An expansion of the 400 Bad Request response code, used when a client certificate is required but not provided.'
        '496_CLASS': classes.CLIENT_ERROR
        SSL_CERTIFICATE_REQUIRED: 496

497 - An expansion of the 400 Bad Request response code, used when the client has made a HTTP request to a port listening for HTTPS requests.

        497: 'HTTP Request Sent to HTTPS Port'
        '497_NAME': 'HTTP_REQUEST_SENT_TO_HTTPS_PORT'
        '497_MESSAGE': 'An expansion of the 400 Bad Request response code, used when the client has made a HTTP request to a port listening for HTTPS requests.'
        '497_CLASS': classes.CLIENT_ERROR
        HTTP_REQUEST_SENT_TO_HTTPS_PORT: 497

499 - Used when the client has closed the request before the server could send a response.

        499: 'Client Closed Request'
        '499_NAME': 'CLIENT_CLOSED_REQUEST'
        '499_MESSAGE': 'Used when the client has closed the request before the server could send a response.'
        '499_CLASS': classes.CLIENT_ERROR
        CLIENT_CLOSED_REQUEST: 499

### Cloudflare

Cloudflare's reverse proxy service expands the 5xx series of errors space to signal issues with the origin server.

      cloudflare:

520 - The 520 error is used as a "catch-all response for when the origin server returns something unexpected", listing connection resets, large headers, and empty or invalid responses as common triggers.

        520: 'Unknown Error'
        '520_NAME': 'UNKNOWN_ERROR'
        '520_MESSAGE': 'The 520 error is used as a "catch-all response for when the origin server returns something unexpected", listing connection resets, large headers, and empty or invalid responses as common triggers.'
        '520_CLASS': classes.SERVER_ERROR
        UNKNOWN_ERROR: 520

521 - The origin server has refused the connection from Cloudflare.

        521: 'Web Server Is Down'
        '521_NAME': 'WEB_SERVER_IS_DOWN'
        '521_MESSAGE': 'The origin server has refused the connection from Cloudflare.'
        '521_CLASS': classes.SERVER_ERROR
        WEB_SERVER_IS_DOWN: 521

522 - Cloudflare could not negotiate a TCP handshake with the origin server.

        522: 'Connection Timed Out'
        '522_NAME': 'CONNECTION_TIMED_OUT'
        '522_MESSAGE': 'Cloudflare could not negotiate a TCP handshake with the origin server.'
        '522_CLASS': classes.SERVER_ERROR
        CONNECTION_TIMED_OUT: 522

523 - Cloudflare could not reach the origin server.

        523: 'Origin Is Unreachable'
        '523_NAME': 'ORIGIN_IS_UNREACHABLE'
        '523_MESSAGE': 'Cloudflare could not reach the origin server.'
        '523_CLASS': classes.SERVER_ERROR
        ORIGIN_IS_UNREACHABLE: 523

524 - Cloudflare was able to complete a TCP connection to the origin server, but did not receive a timely HTTP response.

        524: 'A Timeout Occurred'
        '524_NAME': 'A_TIMEOUT_OCCURRED'
        '524_MESSAGE': 'Cloudflare was able to complete a TCP connection to the origin server, but did not receive a timely HTTP response.'
        '524_CLASS': classes.SERVER_ERROR
        A_TIMEOUT_OCCURRED: 524

525 - Cloudflare could not negotiate a SSL/TLS handshake with the origin server.

        525: 'SSL Handshake Failed'
        '525_NAME': 'SSL_HANDSHAKE_FAILED'
        '525_MESSAGE': 'Cloudflare could not negotiate a SSL/TLS handshake with the origin server.'
        '525_CLASS': classes.SERVER_ERROR
        SSL_HANDSHAKE_FAILED: 525

526 - Cloudflare could not validate the SSL/TLS certificate that the origin server presented.

        526: 'Invalid SSL Certificate'
        '526_NAME': 'INVALID_SSL_CERTIFICATE'
        '526_MESSAGE': 'Cloudflare could not validate the SSL/TLS certificate that the origin server presented.'
        '526_CLASS': classes.SERVER_ERROR
        INVALID_SSL_CERTIFICATE: 526

527 - Error 527 indicates that the request timed out or failed after the WAN connection had been established.

        527: 'Railgun Error'
        '527_NAME': 'RAILGUN_ERROR'
        '527_MESSAGE': 'Error 527 indicates that the request timed out or failed after the WAN connection had been established.'
        '527_CLASS': classes.SERVER_ERROR
        RAILGUN_ERROR: 527
