Svelte Effect Runtime Language Server

v3.0.2 · by Barekey · added 3 November 2026

Svelte Effect Runtime language-server support for Svelte files.

Language servers

How to install

With Forge Super installed, the button above opens the app on this extension, where you press Install. Nothing is installed until you do.

You can also open the Extensions panel in the app and search for Svelte Effect Runtime Language Server. The extension's id is svelte-effect-runtime-language-server.

Don't have Forge Super yet? Download it here.

README

From the extension's repository, written by its authors and not by Mentenaz. See the source.

Svelte Effect Runtime for Zed

This extension registers the SER language server for Zed's existing Svelte language support. For now, keep the stock Zed Svelte extension installed for grammar/highlighting.

The important bit is that SER should be the only Svelte language server running. If the stock Zed Svelte extension is installed, keep it for grammar/highlighting but disable its language server:

{
  "languages": {
    "Svelte": {
      "language_servers": [
        "svelte-effect-runtime-language-server",
        "!svelte-language-server",
        "..."
      ]
    }
  }
}

For local development, install a fresh local copy with one command:

deno task install:zed-local

That builds the sibling language-server package, builds the Zed WASM extension, copies both into Zed's local installed/svelte-effect-runtime directory, and updates Zed's local extension index.

For local development, point Zed at your local language-server binary with lsp.svelte-effect-runtime-language-server.binary.path:

{
  "lsp": {
    "svelte-effect-runtime-language-server": {
      "binary": {
        "path": "/path/to/svelte-effect-runtime-language-server",
        "arguments": ["--stdio"]
      }
    }
  }
}

The extension resolves the server in this order:

lsp.svelte-effect-runtime-language-server.binary.path from Zed settings.
svelte-effect-runtime-language-server on the worktree PATH.
node_modules/svelte-effect-runtime-language-server/.dist/server.cjs beside the extension.
The svelte-effect-runtime-language-server package installed from npm by Zed.

The npm package carries its compiled server, runtime assets, and Node dependencies, so published Zed installs do not need GitHub release downloads. Local testing can still use the Zed settings override above.