Redis store for kemal-session kemal redis session
1.2.0 Latest release released



Redis session store for kemal-session implemented with jgaskins/redis client.


Add this to your application's shard.yml:

    github: crystal-garage/kemal-session-redis-engine


require "kemal"
require "kemal-session"
require "kemal-session-redis-engine"

Kemal::Session.config do |config|
  config.cookie_name = "redis_test"
  config.secret = "a_secret"
  config.engine =
    key_prefix: "my_app:session:"
  config.timeout =, 0, 0)

get "/" do
  puts "Hello World"

post "/sign_in" do |context|"see-it-works", 1)

The engine comes with a number of configuration options:

| Option | Description | | ---------- | ---------------------------------------------------------------------------------------------- | | redis_url | where your redis instance lives. defaults to redis://localhost:6379/0 | | key_prefix | when saving sessions to redis, how should the keys be namespaced. defaults to kemal:session: |

If no options are passed the RedisEngine will try to connect to a Redis using default settings.

Best Practices

Creating a Client

It's very easy for client code to leak Redis connections and you should pass a pool of connections that's used throughout Kemal and the session engine.

Session Administration Performance

Kemal::Session.all and Kemal::Session.each perform a bit differently under the hood. If Kemal::Session.all is used, the RedisEngine will use the SCAN command in Redis and page through all of the sessions, hydrating the Session object and returing an array of all sessions. If session storage has a large number of sessions this could have performance implications. Kemal::Session.each also uses the SCAN command in Redis but instead of creating one large array and enumerating through it, Kemal::Session.each will only hydrate and yield the keys returned from the current cursor. Once that block of sessions has been yielded, RedisEngine will retrieve the next block of sessions.


Redis must be running on localhost and bound to the default port to run specs.


  1. Fork it ( )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request


  github: crystal-garage/kemal-session-redis-engine
  version: ~> 1.2.0
License MIT
Crystal none


Dependencies 2

  • kemal-session ~> 1.0.0
    {'github' => 'kemalcr/kemal-session', 'version' => '~> 1.0.0'}
  • redis~jgaskins ~> 0.7.0
    {'github' => 'jgaskins/redis', 'version' => '~> 0.7.0'}

Development Dependencies 0

Dependents 1

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