This is Perl module Acme::JWT.

INSTALLATION

Acme::JWT installation is straightforward. If your CPAN shell is set up,
you should just be able to do

    % cpan Acme::JWT

Download it, unpack it, then build it as per the usual:

    % perl Makefile.PL
    % make && make test

Then install it:

    % make install

DOCUMENTATION

Acme::JWT documentation is available as in POD. So you can do:

    % perldoc Acme::JWT

to read the documentation online with your favorite pager.

JWT specification 
    http://self-issued.info/docs/draft-jones-json-web-token.html

NAGAYA Shinichiro