Authentication
bard-ai works by simulating a user logging onto Bard, and calling a request. Because of this, bard-ai needs a specific cookie on Bard's websie to be used.
Step 1
Visit https://bard.google.com/ (opens in a new tab), and sign into your Google account.
Step 2
Open the Web Inspector, and go to the Application tab.
Step 3
Spin open the Cookies dropdown, and click the option with https://bard.google.com.
Step 4
Look for the Cookie labeled __Secure-1PSID exactly, and copy it. Now, use this cookie whenever COOKIE_KEY is referred to in the documentation. (bard-ai will not work with any other cookie.)
⚠️
Even though there does not seem to be a direct way to exploit your COOKIE_KEY, it is not a good idea to publically share it anyway. Try to keep it as private as you can.