Just Command Runner

Create readable task automation that matches the repository's installed Just version and existing justfile conventions.

Defaults

• Inspect just --version, the existing justfile/module tree, and just --list before editing. Installed capabilities

and existing syntax are authoritative over this skill's examples.

• Preserve bespoke formatting. Do not rewrite a justfile with just --fmt. Use just --fmt --check only when the

repository explicitly treats the built-in formatter as authoritative. just --dump is inspection output, not a formatting source.

• Define multi-item string sequences one item per line with a parenthesized concatenation. Keep a trailing separator in

every non-final item. Do not combine them into one long string. Triple-quoted strings are for values whose newlines are semantic, not visual wrapping. For example:

  check-steps := (
    "event-class-coverage " +
    "orphan-disposal " +
    "price-coverage"
  )

• When creating a new standalone justfile, use the user's section-banner style. Existing repository organization

overrides that style.

Workflow

1. Determine the requested recipe behavior, inputs, outputs, cwd, shell, environment, dependencies, and success

condition.

1. Use the installed manual (just --help, just --man, or <https://just.systems/man/en/>) for version-sensitive

syntax. Read only the task-specific reference:

1. Make the smallest recipe or setting change. Do not enable unstable features unless the requested design needs them

and the installed version supports them.

1. Validate parsing with just --list or just --summary. Then execute the narrowest safe recipe path. For

state-changing recipes, use an existing dry-run/check mode or inspect the expanded command first.

Opinionated Organization

For a new standalone file, prefer dependency declarations, constants, public recipes, checks, then private helpers. Use set default-list := true when no single default action makes sense and the installed version supports it. Example starting points are in examples/standalone.just and examples/devkit.just. Load one only when creating that shape.

Completion requires a parsable justfile, the requested recipe behavior, and execution or dry-run evidence appropriate to its side effects. Finish with ### ✅ Just workflow ready, a compact recipe/alias/purpose table when several entries changed, and ### 🧪 Verification with exact commands and outcomes. Keep confirmation prompts, recipe data output, compiler output, and just --list output undecorated. Preserve the repository's own banner vocabulary.