Metals v2.0.0-M13: full Scala IDE in VS Code without IntelliJ

If you write Scala outside IntelliJ, Metals (scalameta.metals) is the official answer — the Language Server Protocol implementation that brings type-aware completions, go-to-definition across library sources, integrated test running, and scalafmt formatting to VS Code, Vim, Emacs, Helix, and Zed. 1 Version v2.0.0-M13 Gold shipped on May 20, 2026 — the latest milestone in the active v2 pre-release series — adding a Gradle MBT (Module Build Target) extractor and BSP CodeLenses improvements on top of a full forward-port from the v1.6.7 stable track. 2

The name Metals is a portmanteau of Meta (Scalameta, the compiler toolkit) and LS (Language Server). Development is led by Scala Center (EPFL) and VirtusLab, the firm behind the Scala compiler and scala-cli. 3 The GitHub repository has 2.3k stars, 423 forks, and 10,071 commits. 1

Install

Search Scala (Metals) in the VS Code Extensions panel (publisher: scalameta), or install from the terminal: 4

code --install-extension scalameta.metals

The stable channel installs v1.66.2. To try the v2 pre-release features covered below, open the extension's page in VS Code and click Switch to Pre-Release Version.

Requirements: JDK 11 minimum (JDK 17 default; auto-downloaded via Coursier if none found). Scala 2.13, 2.12, or Scala 3 (3.3.4+). macOS, Linux, or Windows. No JetBrains plugin — IntelliJ IDEA uses its own separately-maintained Scala plugin. 5

The three-step daily workflow

1. Import the build

Open a folder containing build.sbt, build.sc, or a src/main/scala tree. Metals activates automatically and prompts you to import the build. 4

Metals "Import build" notification in VS Code when opening an sbt project — Metals detects the sbt workspace and offers a one-click import — compile diagnostics start appearing in the Problems panel once the build is imported. 4

Behind the scenes, Metals exports the project to Bloop (a fast incremental build server) for sbt, Gradle, Maven, and Mill. You don't need Bloop installed separately. First import on a small cached project takes about 10 seconds; a large uncached project with many dependencies can take 10–15 minutes. 6

2. Run or debug from a code lens

After import, every object with a main method gets a run | debug code lens above its definition line. Every test class gets test | test debug. Click to run — no terminal command needed. 4

run | debug code lenses above object Main in VS Code with Metals — Code lenses above `object Main` — click `run` or `debug` to launch without leaving the editor. 4

For custom JVM flags or arguments, add a .vscode/launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "scala",
      "request": "launch",
      "name": "Run with args",
      "mainClass": "example.Main",
      "args": ["--config", "prod.conf"],
      "jvmOptions": ["-Xmx2g"]
    }
  ]
}

3. Format on save with scalafmt

Metals includes scalafmt (the standard Scala formatter) with no additional install. Enable format-on-save in .vscode/settings.json: 5

{
  "[scala]": {
    "editor.formatOnSave": true
  }
}

If no .scalafmt.conf exists in the project root, Metals creates one. Multi-line strings get | alignment automatically as you type (onTypeFormatting) and when you paste (formatOnPaste), both enabled by default.

Full feature set

Category	What you get
Completions	Auto-import, override completions, exhaustive match cases, string interpolators, file name completions
Navigation	Go-to-definition (project + library jars), find references, find implementations, workspace symbol fuzzy search
Hover	Type at point, symbol signature, docstring
Diagnostics	Syntax errors as-you-type; type errors on save via the build tool
Refactoring	Rename symbol (workspace-wide), code actions (extract method, insert type, convert to/from)
Imports	Organize imports, auto-insert on completion
Implicits	Virtual text decorations showing inferred implicit parameters and conversions
Testing	VS Code Test Explorer (JUnit4, MUnit, Scalatest, Weaver), per-suite run/debug
Worksheets	`*.worksheet.sc` files evaluate on save, results shown as inline hints
MCP server	HTTP + stdio transport for AI agent integration (added in v1.6.0)
Decompiler	Auto-decode `.class` / `.semanticdb` / `.tasty` files (VS Code, added v1.6.7)

Metals Test Explorer in VS Code showing Scala test suites grouped by module with run/debug controls — Test Explorer groups suites by build module — run a single test, a whole suite, or everything at once. 4

What v2.0.0-M13 adds

The v2 series (started May 6, 2026 with M10) is a significant architectural shift: Metals v2 indexes source files directly at roughly 1 million lines per second, making navigation available before the build finishes. 7 Build integration remains required for type errors and third-party dependency navigation.

v2.0.0-M13, released May 20 with contributions from Tomasz Godzik, @snjeza, @odisseus, and @jchyb, brings three headline changes: 2

Gradle MBT extractor (PR #8385): Gradle projects can now use the Module Build Target format to drive Metals imports, the same mechanism introduced for Bazel in M12.
BSP server + CodeLenses (PR #8375): BSP-backed servers now expose run/debug code lenses.
Forward port from v1.6.7: all 37 commits from the April stable release, including stdio transport for the MCP server and .class/.tasty/.semanticdb auto-decompilation.

Caveats worth knowing

v2 is pre-release, and a few known bugs bite. Cross-module navigation with Gradle MBT is broken (issue #8442, reproduced with the Apache Kafka repo — symbols from a different Gradle module can't be resolved). 8 Cross-platform projects (JVM + Scala.js) don't see compile errors in VS Code under v2 (issue #8257). 9 The stable extension channel (v1.66.2 / Metals v1.6.7) has neither issue.

Type errors are build-dependent. Metals shows syntax errors inline as you type, but type-checking requires a save and a round-trip to sbt/Bloop. On large multi-module projects, that delay is measurable. IntelliJ IDEA reimplements parts of the Scala compiler internally, which is why it recovers from type errors faster and without saving. 10

Find references has a gap. Looking up references to Dog.name() won't surface callers of Animal.name() — overridden method references aren't included. 11

No JetBrains target. Metals has no IntelliJ plugin; IntelliJ users stay on the JetBrains Scala plugin. The practical split: VS Code + Metals if you want a lightweight editor or need Vim/Emacs/Helix/Zed; IntelliJ if you need Structural Search and Replace, integrated profiler, or AI Assistant features. 12

Worksheets have a 30-second evaluation timeout and don't support value classes (AnyVal). Move AnyVal subclasses to a separate file as a workaround. 11

Install

Extension ID: scalameta.metals · Stable server: v1.6.7 (extension v1.66.2) · Pre-release server: v2.0.0-M13 (2026-05-20) · IDE: VS Code (also: Vim, Emacs, Helix, Zed, Sublime Text) · Language: Scala 2.12 / 2.13 / 3 · Use case: full language server (completions, navigation, diagnostics, testing, formatting, debug) · License: Apache-2.0 · GitHub: 2.3k ★ 1

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Metals v2.0.0-M13: full Scala IDE in VS Code without IntelliJ

Install

The three-step daily workflow

1. Import the build

2. Run or debug from a code lens

3. Format on save with scalafmt

Full feature set

What v2.0.0-M13 adds

Caveats worth knowing

Install

参考ソース