---
name: "Mojo::Headers"
section: "3pm"
platform: "linux"
package: "libmojolicious-perl"
version: "9.39+dfsg-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Mojo::Headers"
---

# Mojo::Headers(3pm)

HTTP headers

## NAME

Mojo::Headers - HTTP headers

## SYNOPSIS

```
  use Mojo::Headers;
  # Parse
  my $headers = Mojo::Headers->new;
  $headers->parse("Content-Length: 42\x0d\x0a");
  $headers->parse("Content-Type: text/html\x0d\x0a\x0d\x0a");
  say $headers->content_length;
  say $headers->content_type;
  # Build
  my $headers = Mojo::Headers->new;
  $headers->content_length(42);
  $headers->content_type('text/plain');
  say $headers->to_string;
```

## DESCRIPTION

Mojo::Headers is a container for HTTP headers, based on RFC 7230 \<https://tools.ietf.org/html/rfc7230\> and RFC 7231 \<https://tools.ietf.org/html/rfc7231\>.

## ATTRIBUTES

Mojo::Headers implements the following attributes.

### max\_line\_size

```
  my $size = $headers->max_line_size;
  $headers = $headers->max_line_size(1024);
```

Maximum header line size in bytes, defaults to the value of the `"MOJO_MAX_LINE_SIZE"` environment variable or `8192` (8KiB).

### max\_lines

```
  my $num  = $headers->max_lines;
  $headers = $headers->max_lines(200);
```

Maximum number of header lines, defaults to the value of the `"MOJO_MAX_LINES"` environment variable or `100`.

## METHODS

Mojo::Headers inherits all methods from Mojo::Base and implements the following new ones.

### add

```
  $headers = $headers->add(Foo => 'one value');
  $headers = $headers->add(Foo => 'first value', 'second value');
```

Add header with one or more lines.

```
  # "Vary: Accept
  #  Vary: Accept-Encoding"
  $headers->add(Vary => 'Accept')->add(Vary => 'Accept-Encoding')->to_string;
```

### append

```
  $headers = $headers->append(Vary => 'Accept-Encoding');
```

Append value to header and flatten it if necessary.

```
  # "Vary: Accept"
  $headers->append(Vary => 'Accept')->to_string;
  # "Vary: Accept, Accept-Encoding"
  $headers->vary('Accept')->append(Vary => 'Accept-Encoding')->to_string;
```

### clone

```
  my $clone = $headers->clone;
```

Return a new Mojo::Headers object cloned from these headers.

### dehop

```
  $headers = $headers->dehop;
```

Remove hop-by-hop headers that should not be retransmitted.

### every\_header

```
  my $all = $headers->every_header('Location');
```

Similar to "header", but returns all headers sharing the same name as an array reference.

```
  # Get first header value
  say $headers->every_header('Location')->[0];
```

### from\_hash

```
  $headers = $headers->from_hash({'Cookie' => 'a=b'});
  $headers = $headers->from_hash({'Cookie' => ['a=b', 'c=d']});
  $headers = $headers->from_hash({});
```

Parse headers from a hash reference, an empty hash removes all headers.

### header

```
  my $value = $headers->header('Foo');
  $headers  = $headers->header(Foo => 'one value');
  $headers  = $headers->header(Foo => 'first value', 'second value');
```

Get or replace the current header values.

### is\_finished

```
  my $bool = $headers->is_finished;
```

Check if header parser is finished.

### is\_limit\_exceeded

```
  my $bool = $headers->is_limit_exceeded;
```

Check if headers have exceeded "max\_line\_size" or "max\_lines".

### leftovers

```
  my $bytes = $headers->leftovers;
```

Get and remove leftover data from header parser.

### names

```
  my $names = $headers->names;
```

Return an array reference with all currently defined headers.

```
  # Names of all headers
  say for @{$headers->names};
```

### parse

```
  $headers = $headers->parse("Content-Type: text/plain\x0d\x0a\x0d\x0a");
```

Parse formatted headers.

### remove

```
  $headers = $headers->remove('Foo');
```

Remove a header.

### to\_hash

```
  my $single = $headers->to_hash;
  my $multi  = $headers->to_hash(1);
```

Turn headers into hash reference, array references to represent multiple headers with the same name are disabled by default.

```
  say $headers->to_hash->{DNT};
```

### to\_string

```
  my $str = $headers->to_string;
```

Turn headers into a string, suitable for HTTP messages.

## ADDITIONAL METHODS

Additionally, the following shortcuts are available, for accessing and manipulating commonly-used headers:

### accept

```
  my $accept = $headers->accept;
  $headers   = $headers->accept('application/json');
```

Get or replace current header value, shortcut for the `"Accept"` header.

### accept\_charset

```
  my $charset = $headers->accept_charset;
  $headers    = $headers->accept_charset('UTF-8');
```

Get or replace current header value, shortcut for the `"Accept-Charset"` header.

### accept\_encoding

```
  my $encoding = $headers->accept_encoding;
  $headers     = $headers->accept_encoding('gzip');
```

Get or replace current header value, shortcut for the `"Accept-Encoding"` header.

### accept\_language

```
  my $language = $headers->accept_language;
  $headers     = $headers->accept_language('de, en');
```

Get or replace current header value, shortcut for the `"Accept-Language"` header.

### accept\_ranges

```
  my $ranges = $headers->accept_ranges;
  $headers   = $headers->accept_ranges('bytes');
```

Get or replace current header value, shortcut for the `"Accept-Ranges"` header.

### access\_control\_allow\_origin

```
  my $origin = $headers->access_control_allow_origin;
  $headers   = $headers->access_control_allow_origin('*');
```

Get or replace current header value, shortcut for the `"Access-Control-Allow-Origin"` header from Cross-Origin Resource Sharing \<https://www.w3.org/TR/cors/\>.

### allow

```
  my $allow = $headers->allow;
  $headers  = $headers->allow('GET, POST');
```

Get or replace current header value, shortcut for the `"Allow"` header.

### authorization

```
  my $authorization = $headers->authorization;
  $headers          = $headers->authorization('Basic Zm9vOmJhcg==');
```

Get or replace current header value, shortcut for the `"Authorization"` header.

### cache\_control

```
  my $cache_control = $headers->cache_control;
  $headers          = $headers->cache_control('max-age=1, no-cache');
```

Get or replace current header value, shortcut for the `"Cache-Control"` header.

### connection

```
  my $connection = $headers->connection;
  $headers       = $headers->connection('close');
```

Get or replace current header value, shortcut for the `"Connection"` header.

### content\_disposition

```
  my $disposition = $headers->content_disposition;
  $headers        = $headers->content_disposition('foo');
```

Get or replace current header value, shortcut for the `"Content-Disposition"` header.

### content\_encoding

```
  my $encoding = $headers->content_encoding;
  $headers     = $headers->content_encoding('gzip');
```

Get or replace current header value, shortcut for the `"Content-Encoding"` header.

### content\_language

```
  my $language = $headers->content_language;
  $headers     = $headers->content_language('en');
```

Get or replace current header value, shortcut for the `"Content-Language"` header.

### content\_length

```
  my $len  = $headers->content_length;
  $headers = $headers->content_length(4000);
```

Get or replace current header value, shortcut for the `"Content-Length"` header.

### content\_location

```
  my $location = $headers->content_location;
  $headers     = $headers->content_location('http://127.0.0.1/foo');
```

Get or replace current header value, shortcut for the `"Content-Location"` header.

### content\_range

```
  my $range = $headers->content_range;
  $headers  = $headers->content_range('bytes 2-8/100');
```

Get or replace current header value, shortcut for the `"Content-Range"` header.

### content\_security\_policy

```
  my $policy = $headers->content_security_policy;
  $headers   = $headers->content_security_policy('default-src https:');
```

Get or replace current header value, shortcut for the `"Content-Security-Policy"` header from Content Security Policy 1.0 \<https://www.w3.org/TR/CSP/\>.

### content\_type

```
  my $type = $headers->content_type;
  $headers = $headers->content_type('text/plain');
```

Get or replace current header value, shortcut for the `"Content-Type"` header.

### cookie

```
  my $cookie = $headers->cookie;
  $headers   = $headers->cookie('f=b');
```

Get or replace current header value, shortcut for the `"Cookie"` header from RFC 6265 \<https://tools.ietf.org/html/rfc6265\>.

### date

```
  my $date = $headers->date;
  $headers = $headers->date('Sun, 17 Aug 2008 16:27:35 GMT');
```

Get or replace current header value, shortcut for the `"Date"` header.

### dnt

```
  my $dnt  = $headers->dnt;
  $headers = $headers->dnt(1);
```

Get or replace current header value, shortcut for the `"DNT"` (Do Not Track) header, which has no specification yet, but is very commonly used.

### etag

```
  my $etag = $headers->etag;
  $headers = $headers->etag('"abc321"');
```

Get or replace current header value, shortcut for the `"ETag"` header.

### expect

```
  my $expect = $headers->expect;
  $headers   = $headers->expect('100-continue');
```

Get or replace current header value, shortcut for the `"Expect"` header.

### expires

```
  my $expires = $headers->expires;
  $headers    = $headers->expires('Thu, 01 Dec 1994 16:00:00 GMT');
```

Get or replace current header value, shortcut for the `"Expires"` header.

### host

```
  my $host = $headers->host;
  $headers = $headers->host('127.0.0.1');
```

Get or replace current header value, shortcut for the `"Host"` header.

### if\_modified\_since

```
  my $date = $headers->if_modified_since;
  $headers = $headers->if_modified_since('Sun, 17 Aug 2008 16:27:35 GMT');
```

Get or replace current header value, shortcut for the `"If-Modified-Since"` header.

### if\_none\_match

```
  my $etag = $headers->if_none_match;
  $headers = $headers->if_none_match('"abc321"');
```

Get or replace current header value, shortcut for the `"If-None-Match"` header.

### last\_modified

```
  my $date = $headers->last_modified;
  $headers = $headers->last_modified('Sun, 17 Aug 2008 16:27:35 GMT');
```

Get or replace current header value, shortcut for the `"Last-Modified"` header.

### link

```
  my $link = $headers->link;
  $headers = $headers->link('<http://127.0.0.1/foo/3>; rel="next"');
```

Get or replace current header value, shortcut for the `"Link"` header from RFC 5988 \<https://tools.ietf.org/html/rfc5988\>.

### links

```
  my $links = $headers->links;
  $headers  = $headers->links({next => 'http://example.com/foo', prev => 'http://example.com/bar'});
```

Get or set web links from or to `"Link"` header according to RFC 5988 \<http://tools.ietf.org/html/rfc5988\>.

```
  # Extract information about next page
  say $headers->links->{next}{link};
  say $headers->links->{next}{title};
```

### location

```
  my $location = $headers->location;
  $headers     = $headers->location('http://127.0.0.1/foo');
```

Get or replace current header value, shortcut for the `"Location"` header.

### origin

```
  my $origin = $headers->origin;
  $headers   = $headers->origin('http://example.com');
```

Get or replace current header value, shortcut for the `"Origin"` header from RFC 6454 \<https://tools.ietf.org/html/rfc6454\>.

### proxy\_authenticate

```
  my $authenticate = $headers->proxy_authenticate;
  $headers         = $headers->proxy_authenticate('Basic "realm"');
```

Get or replace current header value, shortcut for the `"Proxy-Authenticate"` header.

### proxy\_authorization

```
  my $authorization = $headers->proxy_authorization;
  $headers          = $headers->proxy_authorization('Basic Zm9vOmJhcg==');
```

Get or replace current header value, shortcut for the `"Proxy-Authorization"` header.

### range

```
  my $range = $headers->range;
  $headers  = $headers->range('bytes=2-8');
```

Get or replace current header value, shortcut for the `"Range"` header.

### referer

```
  my $referrer = $headers->referer;
  $headers     = $headers->referer('http://example.com');
```

Alias for "referrer".

### referrer

```
  my $referrer = $headers->referrer;
  $headers     = $headers->referrer('http://example.com');
```

Get or replace current header value, shortcut for the `"Referer"` header, there was a typo in RFC 2068 \<https://tools.ietf.org/html/rfc2068\> which resulted in `"Referer"` becoming an official header.

### sec\_websocket\_accept

```
  my $accept = $headers->sec_websocket_accept;
  $headers   = $headers->sec_websocket_accept('s3pPLMBiTxaQ9kYGzzhZRbK+xOo=');
```

Get or replace current header value, shortcut for the `"Sec-WebSocket-Accept"` header from RFC 6455 \<https://tools.ietf.org/html/rfc6455\>.

### sec\_websocket\_extensions

```
  my $extensions = $headers->sec_websocket_extensions;
  $headers       = $headers->sec_websocket_extensions('foo');
```

Get or replace current header value, shortcut for the `"Sec-WebSocket-Extensions"` header from RFC 6455 \<https://tools.ietf.org/html/rfc6455\>.

### sec\_websocket\_key

```
  my $key  = $headers->sec_websocket_key;
  $headers = $headers->sec_websocket_key('dGhlIHNhbXBsZSBub25jZQ==');
```

Get or replace current header value, shortcut for the `"Sec-WebSocket-Key"` header from RFC 6455 \<https://tools.ietf.org/html/rfc6455\>.

### sec\_websocket\_protocol

```
  my $proto = $headers->sec_websocket_protocol;
  $headers  = $headers->sec_websocket_protocol('sample');
```

Get or replace current header value, shortcut for the `"Sec-WebSocket-Protocol"` header from RFC 6455 \<https://tools.ietf.org/html/rfc6455\>.

### sec\_websocket\_version

```
  my $version = $headers->sec_websocket_version;
  $headers    = $headers->sec_websocket_version(13);
```

Get or replace current header value, shortcut for the `"Sec-WebSocket-Version"` header from RFC 6455 \<https://tools.ietf.org/html/rfc6455\>.

### server

```
  my $server = $headers->server;
  $headers   = $headers->server('Mojo');
```

Get or replace current header value, shortcut for the `"Server"` header.

### server\_timing

```
  my $timing = $headers->server_timing;
  $headers   = $headers->server_timing('app;desc=Mojolicious;dur=0.0001');
```

Get or replace current header value, shortcut for the `"Server-Timing"` header from Server Timing \<https://www.w3.org/TR/server-timing/\>.

### set\_cookie

```
  my $cookie = $headers->set_cookie;
  $headers   = $headers->set_cookie('f=b; path=/');
```

Get or replace current header value, shortcut for the `"Set-Cookie"` header from RFC 6265 \<https://tools.ietf.org/html/rfc6265\>.

### status

```
  my $status = $headers->status;
  $headers   = $headers->status('200 OK');
```

Get or replace current header value, shortcut for the `"Status"` header from RFC 3875 \<https://tools.ietf.org/html/rfc3875\>.

### strict\_transport\_security

```
  my $policy = $headers->strict_transport_security;
  $headers   = $headers->strict_transport_security('max-age=31536000');
```

Get or replace current header value, shortcut for the `"Strict-Transport-Security"` header from RFC 6797 \<https://tools.ietf.org/html/rfc6797\>.

### te

```
  my $te   = $headers->te;
  $headers = $headers->te('chunked');
```

Get or replace current header value, shortcut for the `"TE"` header.

### trailer

```
  my $trailer = $headers->trailer;
  $headers    = $headers->trailer('X-Foo');
```

Get or replace current header value, shortcut for the `"Trailer"` header.

### transfer\_encoding

```
  my $encoding = $headers->transfer_encoding;
  $headers     = $headers->transfer_encoding('chunked');
```

Get or replace current header value, shortcut for the `"Transfer-Encoding"` header.

### upgrade

```
  my $upgrade = $headers->upgrade;
  $headers    = $headers->upgrade('websocket');
```

Get or replace current header value, shortcut for the `"Upgrade"` header.

### user\_agent

```
  my $agent = $headers->user_agent;
  $headers  = $headers->user_agent('Mojo/1.0');
```

Get or replace current header value, shortcut for the `"User-Agent"` header.

### vary

```
  my $vary = $headers->vary;
  $headers = $headers->vary('*');
```

Get or replace current header value, shortcut for the `"Vary"` header.

### www\_authenticate

```
  my $authenticate = $headers->www_authenticate;
  $headers         = $headers->www_authenticate('Basic realm="realm"');
```

Get or replace current header value, shortcut for the `"WWW-Authenticate"` header.

## SEE ALSO

Mojolicious, Mojolicious::Guides, \<https://mojolicious.org\>.