Show HN: Specific (YC F25) – Build backends with specifications instead of code

That's a fair take. We are planning on showing the output code to remove that need for trust, but focused on other things for the open beta.

As for who it's for, we are targeting technical people who might know how to build backends in code, but we believe it can be done more productively through specs. The specs remove the need for boilerplate code and more closely match the business requirements of the system. One common example of this amongst our users is building third-party integrations. That can require a lot of boilerplate code and libraries to achieve. In Specific, it can be as easy as linking out to API docs.

That's a good question!

> If Specific regenerates code from the spec each time (which I'm not sure it does), there's the potential for different code each time even for parts of the spec that haven't changed

It doesn't. When the spec changes, the coding agent takes the diff and turns it into the equivalent change to the codebase. The tests also run each time so that the coding agent does cause a regression as part of this. Although as you say, test suites are often incomplete. We are aiming to make it easier to build complete test suites in Specific than in regular code though because they are a part of the spec and the agent can you help write them as well.

We haven't done much yet in this area but I'm quite excited about how to evolve the codebase over time. I think we have an advantage in that a system evolving also means the specs are evolving and growing. We can maintain a loose mapping behind the scenes between specs and code for the coding agent, to give it the right context and keep code changes localised even as a system grows large. We can also refactor incrementally as we go as given that it becomes the job of the coding agent, instead of a human that might put it off.

I think specs embedded into existing code is a good idea as well, in fact there is some work being done in this area, like the Kiro editor: https://kiro.dev/

We have gone the all-specs route for now because it gives us an opportunity to try build that DX that you mention (which will be critical), without having to adapt to existing codebases that are no covered by specs.

Ah yes, we haven't spent as much effort on it as we could. Mostly been building the product itself!

Pricing is still to be determined. I imagine we will charge for infra usage (processing, storage, etc) in line with other providers like Supabase. We will also charge per-seat for developing inside Specific, which will likely be a fixed price with some token usage limit.

As for what's part of the beta, we currently offer hosting for the API and processing of requests, as well as a database to back it. We are planning on expanding that to support more use cases like background jobs, cron jobs, and object storage.

We don't offer built-in authentication and aren't planning to at this point. That's because we think there are much better providers (like Auth0, Clerk, WorkOS) that you can easily integrate in your Specific app by just specifying it!

That's the main difference to something like Supabase. We provide the infra automatically for your app to do what you need it to, but aren't opinionated around user-facing aspects like authentication. We also have the opportunity to be quite a bit more flexible. Building integrations with external APIs on Supabase for example often requires writing edge functions. In Specific, you can simply make it part of your specification.

That's fair! We have considered how we could offer an open-source version of Specific but haven't found a good model for it yet. We are definitely open to it though!

Curious to hear more about the entity relationship definition. The schema for the entities and relationships is naturally an important part of it but how do you define the logic needed around them? For example integrations with external APIs