Running in CI

Nothing is CI-specific: install, point entryPoint at your CSS, run oxlint. The rest of this page makes it faster and easier to read.

Annotations on the pull request

oxlint -f github prints each diagnostic as a GitHub Actions annotation, so it shows up inline in the pull request's diff:

::error file=src/Button.tsx,line=1,endLine=1,col=39,endColumn=62,title=tailwindcss(no-unknown-classes)::src/Button.tsx:1:39: "itms-center" is not a valid Tailwind class. Did you mean "items-center"?

Cache the design system between jobs

The first time the plugin sees a CSS entry point it precomputes that design system — every class Tailwind can generate for it, with its CSS — and writes the result to a disk cache. Later runs read it back and skip that step. The precompute is most of a cold run: on shadcn/ui's apps/v4, with every rule on, a cold run takes several times as long as a warm one.

A GitHub-hosted runner starts every job on a fresh machine, so every job pays the cold start. Put the cache in a directory you persist between jobs, with the OXLINT_TAILWINDCSS_CACHE_DIR environment variable:

- uses: actions/cache@v6
  with:
    path: ~/.cache/oxlint-tailwindcss
    key: oxlint-tailwindcss-${{ runner.os }}-${{ hashFiles('pnpm-lock.yaml', 'src/**/*.css') }}

- run: OXLINT_TAILWINDCSS_CACHE_DIR="$HOME/.cache/oxlint-tailwindcss" npx oxlint -f github

• The plugin creates the directory if it doesn't exist. The variable takes the path as is — ~ is not expanded, which is why the step uses $HOME.
• A run that finds its design system in the cache doesn't compute it again. The directory also keeps the canonical form of each arbitrary-value class the rules meet (p-[2px]), so it grows a little as your code does; that part only saves time. Files the plugin hasn't used for 30 days are removed whenever it computes a new design system, so a cache restored run after run doesn't pile up old ones.
• The key above changes with the lockfile (which pins the Tailwind version and any Tailwind plugins) and with your CSS. Adjust the CSS glob to where your stylesheets live.

See which rules cost what

--debug timings prints a per-rule table after the lint. JS plugin rules, like these, are in it from oxlint 1.84:

npx oxlint -f default --debug timings

Rule timings:
Rule                               Time (ms)  Relative  Calls  Source
--------------------------------  ----------  --------  -----  ---------
tailwindcss/no-unknown-classes        87.440     99.5%      2  js-plugin
tailwindcss/no-duplicate-classes       0.467      0.5%      2  js-plugin

It prints nothing with -f github: run it as a separate step, or locally, with the default format.

What to trust

The cache holds data the rules act on — including what the autofixes rewrite classes to. Treat it like any other build artifact:

• Restore only caches your own workflows saved.
• Don't point OXLINT_TAILWINDCSS_CACHE_DIR at a directory other users or jobs can write to. A directory the plugin creates is private to its owner (0700).

The plugin checks the shape of every cache file it reads and recomputes one that is corrupt or truncated, so a bad cache costs a cold start, not a crash.

See also the environment variables reference.