The Response::PHRASES table maps status codes to their IANA-registered reason phrases. When you construct a Response without an explicit reason, the corresponding phrase from this table is used.
| Code | Reason Phrase |
|---|---|
| 100 | Continue |
| 101 | Switching Protocols |
| 102 | Processing |
| 103 | Early Hints |
| 200 | OK |
| 201 | Created |
| 202 | Accepted |
| 203 | Non-Authoritative Information |
| 204 | No Content |
| 205 | Reset Content |
| 206 | Partial Content |
| 207 | Multi-status |
| 208 | Already Reported |
| 210 | Content Different |
| 226 | IM Used |
| 300 | Multiple Choices |
| 301 | Moved Permanently |
| 302 | Found |
| 303 | See Other |
| 304 | Not Modified |
| 305 | Use Proxy |
| 306 | Switch Proxy |
| 307 | Temporary Redirect |
| 308 | Permanent Redirect |
| 400 | Bad Request |
| 401 | Unauthorized |
| 402 | Payment Required |
| 403 | Forbidden |
| 404 | Not Found |
| 405 | Method Not Allowed |
| 406 | Not Acceptable |
| 407 | Proxy Authentication Required |
| 408 | Request Time-out |
| 409 | Conflict |
| 410 | Gone |
| 411 | Length Required |
| 412 | Precondition Failed |
| 413 | Request Entity Too Large |
| 414 | Request-URI Too Large |
| 415 | Unsupported Media Type |
| 416 | Requested range not satisfiable |
| 417 | Expectation Failed |
| 418 | I'm a teapot |
| 421 | Misdirected Request |
| 422 | Unprocessable Entity |
| 423 | Locked |
| 424 | Failed Dependency |
| 425 | Unordered Collection |
| 426 | Upgrade Required |
| 428 | Precondition Required |
| 429 | Too Many Requests |
| 431 | Request Header Fields Too Large |
| 451 | Unavailable For Legal Reasons |
| 500 | Internal Server Error |
| 501 | Not Implemented |
| 502 | Bad Gateway |
| 503 | Service Unavailable |
| 504 | Gateway Time-out |
| 505 | HTTP Version not supported |
| 506 | Variant Also Negotiates |
| 507 | Insufficient Storage |
| 508 | Loop Detected |
| 510 | Not Extended |
| 511 | Network Authentication Required |
Pass a reason explicitly when you need something off-canon:
$response = new Response(418, [], null, '1.1', "I'm a coffee maker, actually");
$response = $response->withStatus(599, 'Network connect timeout error');Status codes are validated against the inclusive range 100..599. Anything else raises InvalidArgumentException.
Codes that aren't in the table get an empty reason phrase. Many proxies and clients are fine with that; some refuse to parse a status line without a phrase. Pick a phrase yourself if you're emitting a non-standard code:
$response = (new Response())->withStatus(599, 'Network connect timeout error');