Catalyst::Plugin::Starch - Catalyst session plugin via Starch.


    package MyApp;
    use Catalyst qw(
        'Plugin::Starch' => {
            cookie_name => 'my_session',
            store => { class=>'::Memory' },


Integrates Starch with Catalyst providing a compatible replacement for Catalyst::Plugin::Session.

Is is recommended that as part of implementing this module in your site that you also create an in-house unit test using Test::Starch.

Note that this plugin is a Moose::Role which means that Catalyst will apply the plugin to the Catalyst object in reverse order than that listed in the use Catalyst stanza. This may not matter for you, but to be safe, declare the Starch plugin after any other Starch plugins or any other plugins that depend on sessions.


Configuring Starch is a matter of setting the Plugin::Starch configuration key in your root Catalyst application class:

        'Plugin::Starch' => {
            store => { class=>'::Memory' },

In addition to the arguments you would normally pass to Starch you can also pass a plugins argument which will be combined with the plugins from "default_starch_plugins".

See Starch for more information about configuring Starch.


This module is mostly API compliant with Catalyst::Plugin::Session. The way you configure this plugin will be different, but all your code that uses sessions, or other plugins that use sessions, should not need to be changed unless they depend on undocumented features.

Everything documented in the "METHODS" in Catalyst::Plugin::Session section is supported except for:

  • The flash, clear_flash, and keep_flash methods are not implemented as its really a terrible idea. If this becomes a big issue for compatibility with existing code and plugins then this may be reconsidered.

  • The session_expire_key method is not supported, but can be if it is deemed a good feature to port.

Everything in the "INTERNAL METHODS" in Catalyst::Plugin::Session section is supported except for:

  • The check_session_plugin_requirements, setup_session, initialize_session_data, validate_session_id, generate_session_id, session_hash_seed, calculate_extended_session_expires, calculate_initial_session_expires, create_session_id_if_needed, delete_session_id, extend_session_expires, extend_session_id, get_session_id, reset_session_expires, set_session_id, and initial_session_expires methods are not supported. Some of them could be, if a good case for their existence presents itself.

  • The setup, prepare_action, and finalize_headers methods are not altered because they do not need to be.

The above listed unimplemented methods and attributes will throw an exception if called.


Benchmarking Catalyst::Plugin::Session and Catalyst::Plugin::Starch it was found that Starch is 1.5x faster (or, ~65% the run-time). While this is a fairly big improvement, the difference in real-life should be a savings of one or two millisecond per request.

Most of this performance gain is made by the fact that Starch does not use Moose and instead it uses Moo which has many run-time performance benefits.



The ID of the session.


Returns the time when the session will expire (in epoch time). If there is no session then 0 will be returned.


Returns the reason value passsed to "delete_session". Two common values are:

  • address mismatch

  • session expired


This attribute returns the base set plugins that the "starch" object will be built with. Note that this does not include any additional plugins you specify in the "CONFIGURATION".

The intention of this attribute is for other Catalyst plugins, such as Catalyst::Plugin::Starch::Cookie, to be able to declare additional Starch plugins by around()ing this and injecting their own plugins into the array ref.


This holds the underlying Starch::State object.



The Starch::Manager object. This gets automatically constructed from the Plugin::Starch Catalyst configuration key per "CONFIGURATION".



    $c->session->{foo} = 45;
    $c->session( foo => 45 );
    $c->session({ foo => 45 });

Returns a hash ref of the session data which may be modified and will be stored at the end of the request.

A hash list or a hash ref may be passed to set values.


    $c->delete_session( $reason );

Deletes the session, optionally with a reason specified.


Saves the session to the store.



Generates a new ID for the session but retains the session data in the new session.

Some interesting discussion as to why this is useful is at "METHODS" in Catalyst::Plugin::Session under the change_session_id method.


Sets the expires duration on the session which defaults to the global expires set in "CONFIGURATION".


Currently this always returns 1.


Calls "reap_expired" in Starch::Store on the store. This method is here for backwards compatibility with Catalyst::Plugin::Session which expects you to delete expired sessions within the context of an HTTP request. Since starch is available independently from Catalyst you should consider calling reap_expired yourself within a cronjob.

If the store does not support expired session reaping then an exception will be thrown.


Please submit bugs and feature requests to the Catalyst-Plugin-Starch GitHub issue tracker:


    Aran Clary Deltac <>


Thanks to ZipRecruiter for encouraging their employees to contribute back to the open source ecosystem. Without their dedication to quality software development this distribution would not exist.


This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.