use strict;
use warnings;

use Data::Dumper;
use MediaWiki::API;

my $mw = MediaWiki::API->new();
$mw->{config}->{api_url} = 'https://cabig-kc.nci.nih.gov/Vocab/KC/api.php';

# modify the LWP::UserAgent object so it looks like a browser
$mw->{ua}->agent( 'Mozilla/5.0' );

# https://cabig-kc.nci.nih.gov/Vocab/KC/api.php?action=query&list=allpages&aplimit=max
my $titles = $mw->api( { action => 'query', list => 'allpages', aplimit => 'max' } )
	|| die $mw->{error}->{code} . ': ' . $mw->{error}->{details};

##</code><code>##

2: 403 Forbidden : error occurred when accessing https://cabig-kc.nci.nih.gov/Vocab/KC/api.php

##</code><code>##

use strict;
use warnings;

use LWP::UserAgent;

my $ua = LWP::UserAgent->new();
$ua->agent( 'Mozilla/5.0' );

my $url = 'https://cabig-kc.nci.nih.gov/Vocab/KC/api.php?action=query&list=allpages&aplimit=max';

my $response = $ua->get( $url );

if( $response->is_success )
{
	print $response->content;
}
else
{
	print "Error: " . $response->status_line . "\n";
}