Effect Language Service (tsgo)

Effect Language Service (tsgo) for Zed

Zed extension for the Effect Language Service powered by @effect/tsgo.

Requirements

This extension starts the language server binary for Zed. You still need to set up your project for @effect/tsgo itself.

When installing this as a dev extension, Zed compiles the extension for wasm32-wasip2. Install that Rust target first:

rustup target add wasm32-wasip2

If the target is installed but Zed still reports can't find crate for core or std, make sure Zed is using the rustup cargo and rustc, not another Rust installation such as Homebrew. Putting ~/.cargo/bin before /opt/homebrew/bin in PATH is usually enough.

You also need a native TypeScript install alongside @effect/tsgo. As of TypeScript 7.0 stable, this is just the regular typescript package:

npm install -D typescript@7

Nightlies still ship under @typescript/native-preview if you want the bleeding edge instead:

npm install -D @typescript/native-preview

@effect/tsgo detects whichever one is installed.

You also need the Effect language service plugin configured in your tsconfig.json (see Recommended Setup below).

Recommended Setup

This extension runs the @effect/tsgo binary directly. That binary is a superset of TypeScript-Go with the Effect language service compiled in, so it acts as your sole TypeScript language server so you don't need vtsls or typescript-language-server running alongside it.

1. Configure tsconfig.json

Add the Effect language service plugin so diagnostics are enabled:

// tsconfig.json
{
  "compilerOptions": {
    "plugins": [{ "name": "@effect/language-service" }],
  },
}

See the @effect/tsgo README for the full list of plugin options (diagnostic severities, refactors, import aliases, etc.).

2. Enable in Zed

Point your TypeScript-family languages at effect-tsgo and disable Zed's built-in TypeScript servers so you don't get duplicate diagnostics:

// .zed/settings.json
{
  "languages": {
    "TypeScript": {
      "language_servers": [
        "effect-tsgo",
        "!vtsls",
        "!typescript-language-server",
      ],
    },
    "TSX": {
      "language_servers": [
        "effect-tsgo",
        "!vtsls",
        "!typescript-language-server",
      ],
    },

    // Optional
    "JavaScript": {
      "language_servers": [
        "effect-tsgo",
        "!vtsls",
        "!typescript-language-server",
      ],
    },
    "JSX": {
      "language_servers": [
        "effect-tsgo",
        "!vtsls",
        "!typescript-language-server",
      ],
    },
  },
}

About npx @effect/tsgo setup

Running setup is optional with this extension. It adds the @effect/tsgo dependency, writes the tsconfig.json plugin block, and prints editor hints, but the extension already auto-installs @effect/tsgo for you, and the tsconfig block above is the only project-side piece that matters. If you'd rather run it, npx @effect/tsgo setup handles step 1 for you.

You do not need the "prepare": "effect-tsgo patch" script. patch exists to patch a plain native-TypeScript install so a generic tsgo binary loads the Effect language service. Since this extension launches the dedicated @effect/tsgo binary (which already embeds the language service), the patch step does nothing useful here.

Configuration

The extension resolves the server binary in this order:

1. lsp.effect-tsgo.binary.path
2. lsp.effect-tsgo.settings.package_version
3. latest @effect/tsgo from npm

Important: the shipped executable is now tsc (matching TypeScript-Go upstream). Older @effect/tsgo packages still ship tsgo; this extension accepts either. Prefer the real native binary, not the effect-tsgo CLI name.

Pin A Package Version

{
  "lsp": {
    "effect-tsgo": {
      "settings": {
        "package_version": "0.0.15"
      }
    }
  }
}

Use A Local Binary

Prefer the real native tsc binary (or tsgo on older packages), not the effect-tsgo CLI name.

{
  "lsp": {
    "effect-tsgo": {
      "binary": {
        "path": "/absolute/path/to/node_modules/@effect/tsgo-darwin-arm64/lib/tsc"
      }
    }
  }
}