# fstack demo > A throwaway demo product that proves the fstack template end to end, for the fstack owner. ## Docs - [API reference](https://preview.demo.meduza.digital/docs/api): every HTTP endpoint, its auth and its responses - [OpenAPI document](https://preview.demo.meduza.digital/docs/openapi.json): the same API as OpenAPI 3.1 JSON - [Authentication](https://preview.demo.meduza.digital/docs/authentication): How a request proves who is signed in, and what the API answers when it can't. ## Help - [Plans and billing](https://preview.demo.meduza.digital/help/billing): Buy a plan or credits, see what you have, and manage payment and cancelling. - [Emails we send you](https://preview.demo.meduza.digital/help/emails): Which emails your account gets, where they come from, and what to do when one doesn't arrive. - [Attach a file to a note](https://preview.demo.meduza.digital/help/files): Upload one file to a note, and download it again with a link that expires. - [Product news](https://preview.demo.meduza.digital/help/product-news): Turn product emails on or off, what you get once they're on, and how to stop them. - [Contact support](https://preview.demo.meduza.digital/help/contact-support): Reach a person by chat or email, and what happens to your message. ## Optional - [Changelog](https://preview.demo.meduza.digital/changelog): what changed, newest first