Svelte Check Daemon

Makes `svelte-check` instant

svelte-check-daemon

Instant svelte-check typechecking and diagnostics in SvelteKit projects, by using a daemon that monitors svelte-check --watch and returns the latest results when you run svelte-check-daemon check.

Usage

Add @ampcode/svelte-check-daemon as a dependency to your project:

npm install --save-dev @ampcode/svelte-check-daemon
# -or-
pnpm add -D @ampcode/svelte-check-daemon

Then update your package.json scripts to run svelte-check-daemon start alongside your dev server and svelte-check-daemon check to get results:

{
    "scripts": {
        "dev": "concurrently \"svelte-check-daemon start --tsconfig tsconfig.json\" \"vite dev\"",
        "check": "svelte-check-daemon check"
    }
}

This uses concurrently to run both processes and ensure the daemon is properly terminated when you stop the dev server.

If the daemon isn't running, svelte-check-daemon check will just run svelte-check, which is a fallback in CI or if you've forgotten to run the daemon.

Commands

Command	Description
`svelte-check-daemon start`	Start the daemon (runs `svelte-check --watch` in background)
`svelte-check-daemon check`	Get the latest results from the daemon
`svelte-check-daemon stop`	Stop the running daemon
`svelte-check-daemon status`	Show daemon status

Options

Option	Description
`--workspace <path>`	Path to workspace (default: current directory)
`--tsconfig <path>`	Path to tsconfig.json
`--help`	Show help message

Signals

Signal	Description
`SIGHUP`	Restarts `svelte-check --watch`. Useful when you want to force a full recheck without restarting the daemon.

To force a restart: pkill -HUP svelte-check-daemon

AGENTS.md

Add this to your project's AGENTS.md to help AI agents work with the daemon:

If svelte-check results seem stale, run `pkill -HUP svelte-check-daemon` to force a full recheck.

Environment variables

Variable	Description
`SVELTE_CHECK_WATCH_BIG_CHANGES`	Path to a directory (relative to cwd) to watch for deleted files. When a file is deleted in this directory, `svelte-check --watch` is restarted. Useful when `svelte-check --watch` gets out of sync after many file deletions.
`NO_SVELTE_CHECK_DAEMON`	Set to `1` to disable the daemon (the `start` command will exit immediately, which means checking will always run a full `svelte-check` and not use cached results).
`VERBOSE`	Set to enable verbose logging.

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