Using Nx with SvelteKit — caching without the monorepo

Nx is usually pitched as a monorepo build tool for Angular or React, and there isn’t much written about it in the Svelte ecosystem. But since Nx v18’s Project Crystal, Nx can wrap any JS/TS project non-intrusively — no generator scaffolding, no wrapping your scripts in custom executors. That makes it a lightweight drop-in on a single-project SvelteKit repo, purely for the build cache.

There are existing Nx plugins for Svelte and SvelteKit, but this post skips them and starts from scratch — the vanilla nx init is enough for what we want.

Setting Up Your SvelteKit Project#

1. Create a New SvelteKit Project#

If you haven’t already created your SvelteKit project, you can do so using the following commands:

npx sv create my-sveltekit-nx-app
cd my-sveltekit-nx-app

2. Configure NX for Sveltekit#

To initialize NX in sveltekit project, you just need to install NX in sveltekit project and run the init command

npm i -D nx
npx nx init

You will get few question from this init command

1. what scripts is cacheable - just choose most of the script such as dev, build and test
2. for each script, it will ask whether it will create output
   1. dev - skip
   2. build - .sveltekit
   3. check - skip
   4. lint - skip

you will notice a new nx.json file created at the root of project directory

Run Your SvelteKit Project using NX#

1 of the feature of nx is the cache, when you run build for the first time using NX, it will create a cache for you

npx nx run build #first run
npx nx run build #second run

you will notice on second run, it will be faster and there is a message from NX that said something similar to this Nx read the output from the cache instead of running the command for 1 out of 1 tasks.

Where the cache actually saves you time#

The cache is keyed off the input files and your local Node/pnpm version. If nothing in your source or dependencies has changed since the last run, Nx replays the previous output — reads from disk, no work done. In practice that means:

• CI re-runs after a flaky test. Build step is free.
• Editing a markdown file in a mostly-code repo. Build is free; only lint/test run.
• Switching branches and back. Both branches’ build outputs are cached.

Against a cold Vite build on a SvelteKit site of any size, this is the difference between waiting 30 seconds and waiting 300 milliseconds.

What else Nx gives you#

The cache alone justifies the install, but if you grow into a monorepo two other features become valuable:

• Nx release — versioning, changelogs, and publishing across packages from one command.
• nx graph — a live dependency graph of your projects, useful for spotting accidental cross-package imports.

For a single-project SvelteKit repo you won’t need either. The caching is the win.