Q: Hi- does anybody know how to check which devices have access to my keychain information? Thanks!

Hello top23,

Thanks for using the Apple Support Communities!

I understand that you would like to know what devices are connected to your iCloud Keychain. You can do this on your Mac by following the instructions from the following article. 

Use these steps if you're using OS X Mavericks v10.9 or later:

1. Choose Apple () menu > System Preferences. Click iCloud, then click Account details.

Frequently asked questions about iCloud Keychain - Apple Support

Cheers!