VirtusLab

Add or run Scala CLI integration tests. Use when adding integration tests, debugging RunTests/CompileTests/etc., or working in modules/integration.

Deprecate CLI options, option aliases, using directives, sub-commands, or config keys in Scala CLI. Use when marking a feature as deprecated with a warning.

Add or change using directives in Scala CLI. Use when adding a new //> using directive, registering a directive handler, or editing directive preprocessing.

Reduce Scala compiler or standard library regressions found in community-build projects to minimal, self-contained scala-cli repros. Use when a Scala nightly breaks a project under community-build3, when Codex needs to auto-discover the matching…

Draft GitHub issues for Scala 3 compiler regressions from minimized repros, version boundaries, bisect results, and community-build failures. Use when Codex needs to turn a confirmed Scala 3 regression into a ready-to-file `scala/scala3` issue title and body…

Use whenever invoking the `git machete` CLI to organize branch chains, compute fork points, run stacked rebases/merges, or manage GitHub/GitLab PR/MR chains - especially in a repo that already has a `.git/machete` file. Lists which subcommands modify…

Use when delegating a well-defined implementation task to Orca's autonomous multi-agent flow — a headless plan-code-review CLI to hand a coding task to instead of implementing it yourself.

Look up the public API of any JVM dependency (Scala 3, Scala 2, Java) from the terminal — type signatures, members, docs, and source as Markdown, no JAR unpacking needed. Use this skill whenever you need to call an unfamiliar library method, explore a…

Scala coding style, tooling, and functional programming guidance, with dedicated sections on direct-style Scala, Ox structured concurrency, and synchronous Tapir. Auto-load for any task involving Scala code, especially when using direct-style or "plain" Scala.

Opinionated modern Java (21+) coding best practices, style guides, and anti-patterns. Curated by VirtusLab engineers. Covers code style, null safety, error handling, immutability, testing, concurrency, and tooling.