Does arkType support CommonJS, and is there a way to use it in NestJS?

[exzq12]

which framework better for validate data with arkType?

[MILLERMARRU]

ArkType is ESM-only, no CommonJS build exists. Checking the published package directly confirms it: package.json has "type": "module", and the exports map only has a default condition (pointing at the ESM output) plus a custom ark-ts condition for direct TS resolution, there's no require condition anywhere in it. So require('arktype') will fail regardless of how you configure your project.

For NestJS specifically, that matters because Nest's default compiler output is CommonJS. You have two realistic options:

• Use a dynamic import() inside your CJS Nest code to pull in ArkType at the call site. This works today with zero config changes and is the standard workaround for consuming an ESM-only package from a CJS codebase.
• Configure your Nest project to compile to ESM ("module": "nodenext" or similar, plus the matching tsconfig/build changes). Newer Nest CLI versions support this, but it's a bigger, cross-cutting change since it affects how every other CJS-only dependency in your project resolves too, not something to do just for one validation library.

For a NestJS project already on CJS, dynamic import() is the pragmatic choice. If you're starting fresh and can pick ESM from day one, that avoids the friction entirely, and there's nothing ArkType-specific stopping that.