Launch HN: Stack Auth (YC S24) – An Open-Source Auth0/Clerk Alternative

This came up on Reddit and the founder responded directly there, seemed like they were going to add a tool tip or something to make it clearer.

You're absolutely right (in other comments) that getting the UX and so on right for authn/authz is really hard, and there are a ton of edge cases, but I know from experience that there are a ton of security edge cases too. Things like rotating session tokens at the right time, how that interacts with password resets, HTTP referrers, etc, is all quite tricky to get right. I've built with battle-hardened, decades-old frameworks and still gotten a few details wrong.

To delegate all of this responsibility to a third party product, even if it's open-source, rather than building it yourself, is to give up control. Sure you can edit the code, but can you find the bug in an unfamiliar codebase, effectively test in a testing environment your unfamiliar with, and create a valid build? That's a lot harder.

If I were to delegate that responsibility to a product like this, I'd want to know that they've taken security at least as seriously as I do, ideally much more seriously because it's the core of their product. Right now I'm not convinced.

If it helps you, we delegate the most vulnerable parts of the application, such as OAuth, to lower-level frameworks — similar to the unmanaged auth libraries people use today. We are essentially a thick wrapper around those, to create a full-stack platform from primitives. (Of course, that doesn't mean the thick wrapper cannot be vulnerable, but it helps with some of the most hideous bugs.)

The point I disagree with is that building it yourself is better than delegating it to a third-party — at best, you can secure your auth against vulnerabilities you're aware of. Unfortunately, this fallacy keeps coming up, but generally it's the case that homebrew auth is not more secure than open-source libraries, nor is proprietary code.