# How to set default cookie domain in Rails3

**URL:** <https://www.ruby-forum.com/t/how-to-set-default-cookie-domain-in-rails3/187974>\
**Category:** Rails\
**Created:** [May 3, 2010, 4:14pm UTC](https://www.ruby-forum.com/t/how-to-set-default-cookie-domain-in-rails3/187974 "2010-05-03T16:14:34Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jabulani](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/b9bd4f/32.png) [@jabulani](https://www.ruby-forum.com/u/jabulani)\
**Post date:** [May 3, 2010, 4:14pm UTC](https://www.ruby-forum.com/t/how-to-set-default-cookie-domain-in-rails3/187974/1 "2010-05-03T16:14:34Z")

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I want to set default cookie domain for my application to  
“.mydomain.com” to allow cookie session be preserved across  
subdomains.  
I use =\> config.action\_dispatch.session = {:domain =\>  
“.mydomain.com”} in application.rb, but thats not working. The cookie  
is saved as ‘[mydomain.com](http://mydomain.com)’

Thanks for the help!

---

<div class="post-metadata">

**Author:** ![jabulani](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/b9bd4f/32.png) [@jabulani](https://www.ruby-forum.com/u/jabulani)\
**Post date:** [May 7, 2010, 4:14pm UTC](https://www.ruby-forum.com/t/how-to-set-default-cookie-domain-in-rails3/187974/2 "2010-05-07T16:14:50Z")

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Jabulani wrote:

> I want to set default cookie domain for my application to  
> “.mydomain.com” to allow cookie session be preserved across  
> subdomains.  
> I use =\> config.action\_dispatch.session = {:domain =\>  
> “.mydomain.com”} in application.rb, but thats not working. The cookie  
> is saved as ‘[mydomain.com](http://mydomain.com)’
> 
> Thanks for the help!

Try: Rails.application.config.session\_store :cookie\_store,  
:key =\> ‘\_app\_session’,  
:domain =\> ‘.mydomain.com’

I coved this in a blog post as we ran across this issue today:  
[http://blog.bitzesty.com/rails-3-default-cookie-domain-for-subdomains](http://blog.bitzesty.com/rails-3-default-cookie-domain-for-subdomains)