:P Go through the docs more slowly: https://trello.com/docs/gettingstarted/index.html. This should be fun to mess around with if you have the right packages: strictures, URI::QueryParam, JSON, YAML (not necessary, comment out if you like), Path::Tiny. Set your developer key in your environment or add to the script.

#!/usr/bin/env perl
use 5.010;
use strictures;
use URI;
use URI::QueryParam;
use LWP::UserAgent;
use JSON;
use YAML; # Just for fun/readability.
use Path::Tiny;
use open qw( :encoding(UTF-8) :std );

$ENV{TRELLO_KEY} ||= "YouForgotToSetThis";

my $version = 1; # My guess/interpretation of URL spec.
my $service = URI->new("https://api.trello.com/");
$service->query_param( key => $ENV{TRELLO_KEY} );

my $uri = $service->clone;
# URI from docs -> https://trello.com/docs/gettingstarted/index.html
$uri->path("/$version/board/4d5ea62fd76aa1136000000c");

# Uncomment to get TONS of data -> $uri->query_param( cards => "open" 
+);
$uri->query_param( list_fields => "name,desc" );

my $response = LWP::UserAgent
    ->new
    ->get( $uri );

die $response->as_string unless $response->is_success;

my $data = decode_json( $response->decoded_content );
print YAML::Dump( $data ); # Just to see in human-readable tree.

my $outfile = path("ohai.json"); # Save the JSON to a file.
$outfile->spew_utf8( $response->decoded_content );

say "Check $outfile for the JSON.";

exit 0;
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