This package allows configuring the following items:

  • The PSR-6 CacheItemPoolInterface service to use.
  • The session cookie name.
  • The session cookie domain.
  • The session cookie path.
  • The session cookie secure option.
  • The session cookie httponly option.
  • The session cookie SameSite attribute (since 1.4.0).
  • The cache limiter (which controls how resources using sessions are cached by the browser).
  • When the session expires.
  • When the resource using a session was last modified.
  • Whether or not to create a persistent session cookie (i.e., one that will not expire when the browser is closed).

This document details how to configure each of these items.

Config service

This package looks for a service named config that returns an array or array-like value. Inside this value, it looks for a key named mezzio-session-cache, which is expected to be an associative array or object that acts like an associative array.

return [
    'mezzio-session-cache' => [
        // key/value pairs


By default, the factory will look for a service named Psr\Cache\CacheItemPoolInterface. If found, that service will be used to seed the persistence adapter.

You may also provide a cache_item_pool_service configuration value. If present, this service name will be queried instead.

Using a global pool

To use a global cache item pool, configure the PSR-6 CacheItemPoolInterface service in your dependency configuration:

use Psr\Cache\CacheItemPoolInterface;

return [
    'dependencies' => [
        'factories' => [
            CacheItemPoolInterface::class => FactoryProvidingACachePool::class,

Using a named pool

To use a specific cache item pool:

use Psr\Cache\CacheItemPoolInterface;

return [
    'dependencies' => [
        'factories' => [
            'MoreSpecificPool' => FactoryProvidingACachePool::class,
    'mezzio-session-cache' => [
        'cache_item_pool_service' => 'MoreSpecificPool',

Non-Pool configuration

As noted earlier, you may configure a number of other values to customize your persistence adapter. The following is example configuration, with inline comments detailing expected and default values.

use Psr\Cache\CacheItemPoolInterface;

return [
    'mezzio-session-cache' => [
        // Detailed in the above section; allows using a different
        // cache item pool than the global one.
        'cache_item_pool_service' => CacheItemPoolInterface::class,

        // The name of the session cookie. This name must comply with
        // the syntax outlined in
        'cookie_name' => 'PHPSESSION',

        // The (sub)domain that the cookie is available to. Setting this
        // to a subdomain (such as '') will make the cookie
        // available to that subdomain and all other sub-domains of it
        // (i.e. To make the cookie available to the
        // whole domain (including all subdomains of it), simply set the
        // value to the domain name ('', in this case).
        // Leave this null to use browser default (current hostname).
        'cookie_domain' => null,

        // The path prefix of the cookie domain to which it applies.
        'cookie_path' => '/',

        // Indicates that the cookie should only be transmitted over a
        // secure HTTPS connection from the client. When set to TRUE, the
        // cookie will only be set if a secure connection exists.
        'cookie_secure' => false,

        // When TRUE the cookie will be made accessible only through the
        // HTTP protocol. This means that the cookie won't be accessible
        // by scripting languages, such as JavaScript.
        'cookie_http_only' => false,

        // Available since 1.4.0
        // Asserts that a cookie must not be sent with cross-origin requests,
        // providing some protection against cross-site request forgery attacks (CSRF).
        // Allowed values:
        // - Strict: The browser sends the cookie only for same-site requests
        //   (that is, requests originating from the same site that set the cookie).
        //   If the request originated from a different URL than the current one,
        //   no cookies with the SameSite=Strict attribute are sent.
        // - Lax: The cookie is withheld on cross-site subrequests, such as calls
        //   to load images or frames, but is sent when a user navigates to the URL
        //   from an external site, such as by following a link.
        // - None: The browser sends the cookie with both cross-site and same-site
        //   requests.
        'cookie_same_site' => 'Lax',

        // Governs the various cache control headers emitted when
        // a session cookie is provided to the client. Value may be one
        // of "nocache", "public", "private", or "private_no_expire";
        // semantics are the same as outlined in
        'cache_limiter' => 'nocache',

        // When the cache and the cookie should expire, in seconds. Defaults
        // to 180 minutes.
        'cache_expire' => 10800,

        // An integer value indicating when the resource to which the session
        // applies was last modified. If not provided, it uses the last
        // modified time of, in order,
        // - the public/index.php file of the current working directory
        // - the index.php file of the current working directory
        // - the current working directory
        'last_modified' => null,

        // A boolean value indicating whether or not the session cookie
        // should persist. By default, this is disabled (false); passing
        // a boolean true value will enable the feature. When enabled, the
        // cookie will be generated with an Expires directive equal to the
        // the current time plus the cache_expire value as noted above.
        // As of 1.2.0, developers may define the session TTL by calling the
        // session instance's `persistSessionFor(int $duration)` method. When
        // that method has been called, the engine will use that value even if
        // the below flag is toggled off.
        'persistent' => false,

Using the service

By default, this package define the service Mezzio\Session\Cache\CacheSessionPersistence, assigning it to the factory Mezzio\Session\Cache\CacheSessionPersistenceFactory. After you have installed the package, you will need to tell your application to use this service when using the SessionMiddleware.

The SessionMiddleware looks for the service Mezzio\Session\SessionPersistenceInterface. You can tell your container to use the CacheSessionPersistence in two different ways.

First, you can alias it:

// in config/autoload/
use Mezzio\Session\Cache\CacheSessionPersistence;
use Mezzio\Session\SessionPersistenceInterface;

return [
    'dependencies' => [
        'aliases' => [
            SessionPersistenceInterface::class => CacheSessionPersistence::class,

Second, you can instead assign the SessionPersistenceInterface service to the factory for the CacheSessionPersistence implementation:

// in config/autoload/
use Mezzio\Session\Cache\CacheSessionPersistenceFactory;
use Mezzio\Session\SessionPersistenceInterface;

return [
    'dependencies' => [
        'factories' => [
            SessionPersistenceInterface::class => CacheSessionPersistenceFactory::class,

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