Are you using htmx on that button? If so, you might want to check out the swapping: https://htmx.org/docs/#swapping The default behavior is innerHTML which places the new HTML it receives inside the element that made the call, which create a nested UI effect if you're receiving the whole webpage every time.

I am so that almost definitely explains it. Thanks!

in some situations the answer is to replace innerHTML with outerHTML, though in this case it sounds like you might want to just do a regular form that posts to your endpoint without htmx.

I.e. if you want to refresh the whole page or navigate to a new page, then no need for htmx. but htmx is handy if you want to do some kind of "small" interaction where reloading the page would be overkill/degrade the experience. e.g. I use htmx for the like + dislike buttons in the app I work on.

First thing to check is if config.edn contains a key called :cookie/secret. The key added by default is called :biff.middleware/cookie-secret, so that may be your problem. Are you expecting that Biff takes :cookie/secret and infers that the env var for it should be COOKIE_SECRET? That might be a point of confusion. Biff uses the :cookie/secret key to check config.edn for the name of an environment variable, and then returns the value of that env var.

Ahh so I have to add a secret to secrets.edn and a pointer for that secret into config.edn?

Yep. (though secrets.env, not secrets.edn)

Yeah, just have edn on the brain. Thanks, that's enough for me to get to the next roadblock. Having much fun with biff.

Excellent, glad you're enjoying it!