[webdevladder]

ArkType is a really interesting library that has a difficult time marketing itself. More than being a schema validator, it brings TS types into the runtime, so you can programmatically work with types as data with (near?) full fidelity.

I've been evaluating schema libraries for a better-than-Zod source of truth, and ArkType is where I've been focused. Zod v4 just entered beta[1], and it improves many of my problems with it. For such a mature library to improve like this, v4 is treat and speaks volumes to the quality of engineering. But ArkType has a much larger scope, and feels to me more like a data modeling language than a library. Something I definitely want as a dev!

The main downside I see is that its runtime code size footprint is much larger than Zod. For some frontends this may be acceptable, but it's a real cost that isn't wise to pay in many cases. The good news is with precompilation[2] I think ArkType will come into its own and look more like a language with a compiler, and be suitable for lightweight frontends too.

[1] https://v4.zod.dev/v4

[2] https://github.com/arktypeio/arktype/issues/810

[CharlieDigital]

I recently went down this same rabbit hole for backend and stumbled on Typia[0] and Nestia[1] from the same developer. The DX with this is fantastic, especially when combined with Kysely[2] because now it's pure TypeScript end-to-end (no runtime schema artifacts and validations get AOT inlined).

I was so shocked by how good this is that I ended up writing up a small deck (haven't had time to write this into a doc yet): https://docs.google.com/presentation/d/1fToIKvR7dyvQS1AAtp4Y...

Shockingly good (for backend)

[0] Typia: https://typia.io/

[1] Nestia: https://nestia.io/

[2] https://kysely.dev/

[retropragma]

An interesting development with Typia is that it will need to be rewritten in Go to work with TypeScript 7. https://github.com/samchon/typia/issues/1534#issuecomment-27...

This is because it relies on patching the TypeScript implementation. I'm curious if its approach is even feasible with Go?

[udbhavs]

I was going to ask about how pure types would fill the gap for other validations in Zod like number min/max ranges, but seeing the tags feature use intersection types for that is really neat. I tried assigning a `string & tags.MinLength<4>` to a `string & tags.MinLength<2>` and it's interesting that it threw an error saying they were incompatible.

[surprisedcat]

Thanks for sharing the deck! I had no idea Typia existed and it looks absolutely amazing. I guess I'll be trying it out this weekend or next :)

[sync]

Definitely check out Valibot as well, it may be the smaller footprint zod you’re looking for: https://valibot.dev

[Jaydenaus]

There's also zod mini now too https://v4.zod.dev/packages/mini

[epolanski]

> it brings TS types into the runtime

So...it's a parser. Like Zod or effect schema.

https://effect.website/docs/schema/introduction/

[MrJohz]

No, it's more like a type reflection system, at least as I understand it. You can use it to parse types, but you can also do a lot more than that.

[worble]

> The main downside I see is that its runtime code size footprint is much larger than Zod.

Yes, it unfortunately really does bloat your bundle a lot, which is a big reason I personally chose to go with Valibot instead (it also helps that it's a lot closer to zods API so it's easier to pickup).

Thanks for linking that issue, I'll definitely revisit it if they can get the size down.

[notpushkin]

Personally, I find Zod’s API extremely intimidating. Anything more resembling TypeScript is way better. ArkType is neat, but ideally we’d have something like:

  export reflect type User = {
    id: number;
    username: string;
    // ...
  };

Edit: just remembered about this one: https://github.com/GoogleFeud/ts-runtime-checks