/ 
Fetch-0.04
/ Fetch

NAME

Fetch - HTTP/2 Future-based user agent

VERSION

Version 0.04

SYNOPSIS

use Fetch;

# works out of the box - no event loop to set up
my $res = Fetch->new->get('https://example.com')->get;
print $res->content if $res->is_success;

# every call returns a Fetch::Future; ->get awaits it
my $ua  = Fetch->new(timeout => 10);
my $f   = $ua->post('https://api/things',
                    headers => { 'Content-Type' => 'application/json' },
                    body    => '{"name":"x"}');
my $res = $f->get;

# many requests concurrently on one loop
my @futs = map { $ua->get($_) } @urls;
Fetch::Future->needs_all(@futs)->get;
my @bodies = map { $_->get->content } @futs;

# a live WebSocket
my $ws = $ua->websocket('wss://host/socket')->get;
$ws->send('hello');
my $reply = $ws->next_message->get;

DESCRIPTION

Fetch is an HTTP user agent whose socket, TLS, HTTP/2 framing and HTTP/1.1 parsing hot path lives in vendored C, and whose asynchronous results are Fetch::Future objects that compose with the Hyperman event loop and other CPAN loops (IO::Async, AnyEvent) - or with nothing at all, since Fetch ships its own event loop (Fetch::Loop::Standalone) and uses it automatically.

HTTP/1.1 and HTTP/2 (ALPN-negotiated over TLS), over cleartext and TLS, with keep-alive connection pooling, redirect following, per-request timeouts, streaming response bodies, a cookie jar, JSON request/response helpers, and native WebSockets. Every request method returns a Fetch::Future; ->get on one awaits it, pumping whichever event loop is active (its own if none), so the same code serves both a simple synchronous call and thousands of requests multiplexed on one loop.

CONSTRUCTOR

new(%args)

my $ua = Fetch->new(
    timeout    => 10,
    tls_verify => 1,
    headers    => { 'Accept' => 'application/json' },
    cookie_jar => 1,
);

Create a user agent. All arguments are optional:

loop

The event loop to run on. Omit it and Fetch uses its own Fetch::Loop::Standalone (so ->get just works with no framework). Pass a raw IO::Async::Loop or Hyperman::Loop and it is wrapped automatically; pass the string 'AnyEvent' to drive AnyEvent; or pass a ready-made Fetch::Loop adapter. See "EVENT LOOPS".

headers

Default headers sent on every request, as a hashref, an arrayref of name => value pairs (duplicates preserved), or a Fetch::Headers. Per-request headers are merged on top (see "REQUEST OPTIONS").

agent

The User-Agent string. Defaults to "Fetch/$VERSION".

tls_verify

Whether to verify the peer certificate and hostname for https. Default true. Overridable per request.

timeout

Default per-request deadline in seconds (fractional allowed). 0 (the default) means no timeout. Overridable per request.

max_redirects

How many redirects to follow. Default 5; 0 disables following. Overridable per request.

keep_alive

Reuse connections via a keep-alive pool (default true). Set false to close every connection after one request.

pool_size

Maximum idle connections the keep-alive pool parks (default 32).

A Fetch::CookieJar to store and send cookies (applied across redirects), or a true scalar to create a fresh one. Default: no jar.

simple_response

Resolve requests to a plain unblessed hashref { status => ..., headers => [k, v, ...], content => ... } instead of a blessed Fetch::Response. Read fields directly ($res->{status}, $res->{content}) rather than via methods. This skips the response object's method dispatch on the hot path; the saving is small (a couple of percent) and only shows when you actually read the response, so reach for it when you are consuming millions of responses and want the leanest possible per-response cost. Default false.

REQUEST METHODS

Each returns a Fetch::Future that resolves to a Fetch::Response (or fails with an error string). They never block; call ->get on the future to await the result.

get / head / delete

my $f = $ua->get($url, %opt);

post / put

my $f = $ua->post($url, body => $bytes, %opt);

request($method, $url, %opt)

my $f = $ua->request('PATCH', $url, body => $bytes, %opt);

The general form the verb helpers dispatch to; use it for any method.

REQUEST OPTIONS

Passed as a trailing key => value list to any request method:

headers

Extra headers for this request - a hashref, an arrayref of pairs (keeping duplicate names, e.g. multiple X-* values), or a Fetch::Headers. Each named field overrides the agent default of the same name.

body

The request body (bytes). Content-Length is added automatically unless you set it yourself.

json

A Perl data structure to send as a JSON body: it is encoded and Content-Type: application/json is set (unless you gave your own). Takes precedence over body. Pair it with "json" in Fetch::Response to decode the reply. Encoding uses Cpanel::JSON::XS when installed, else core JSON::PP.

my $res  = $ua->post($url, json => { name => 'x', ok => \1 })->get;
my $data = $res->json;
timeout

Override the agent timeout for this request (seconds; 0 disables it).

tls_verify

Override certificate/hostname verification for this https request.

max_redirects

Override how many redirects this request follows.

on_body

A coderef called with each body chunk as it arrives, instead of buffering. Suits large downloads and server-sent events: the buffer is compacted so an endless stream does not grow memory, and the resolved response body is empty.

$ua->get($url, on_body => sub { my ($chunk) = @_; print $chunk })->get;

WEBSOCKETS

websocket($url, %opt)

my $ws = $ua->websocket('ws://host/echo')->get;   # or wss://

Open a WebSocket (RFC 6455). Returns a Fetch::Future that resolves, after the 101 handshake, to a Fetch::WebSocket for sending and receiving messages. Accepts ws:///wss:// (and http/https); tls_verify and timeout options apply to the handshake.

ACCESSORS

loop

The event-loop adapter this agent runs on.

The Fetch::CookieJar in use, or undef.

THE RESULT

Awaiting a request future yields a Fetch::Response with status, headers (a Fetch::Headers), content, header($name), is_success and is_redirect. A failed request (connection error, timeout, bad TLS, a rejected WebSocket upgrade) fails the future with a message; ->get rethrows it, or inspect $f->failure / $f->is_failed.

EVENT LOOPS

$future->get awaits by pumping the active loop, so a bare synchronous call needs no setup. Hand Fetch a loop to cooperate with an existing async program - requests then fly concurrently on that one loop without blocking it:

use IO::Async::Loop;
my $loop = IO::Async::Loop->new;
my $ua   = Fetch->new(loop => $loop);       # shares this loop
my $f    = $ua->get('https://example.com/');
$loop->loop_once until $f->is_ready;
my $res  = $f->get;

Supported loops: the built-in Fetch::Loop::Standalone, plus Fetch::Loop::IOAsync, Fetch::Loop::AnyEvent and Fetch::Loop::Hyperman.

SEE ALSO

Fetch::Response, Fetch::Headers, Fetch::CookieJar, Fetch::WebSocket, Fetch::Future, Fetch::Loop and the loop adapters Fetch::Loop::Standalone, Fetch::Loop::IOAsync, Fetch::Loop::AnyEvent, Fetch::Loop::Hyperman.

AUTHOR

LNATION <email@lnation.org>

LICENSE AND COPYRIGHT

This software is Copyright (c) 2026 by LNATION.

This is free software, licensed under the Artistic License 2.0.