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, andjust --listbefore editing. Installed capabilities and existing syntax are authoritative over this skill's examples. -
Preserve bespoke formatting. Do not rewrite a justfile with
just --fmt. Usejust --fmt --checkonly when the repository explicitly treats the built-in formatter as authoritative.just --dumpis 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:
-
When creating a new standalone justfile, use the user's section-banner style. Existing repository organization overrides that style.
Workflow
-
Determine the requested recipe behavior, inputs, outputs, cwd, shell, environment, dependencies, and success condition.
-
Use the installed manual (
just --help,just --man, or https://just.systems/man/en/) for version-sensitive syntax. Read only the task-specific reference: -
Make the smallest recipe or setting change. Do not enable unstable features unless the requested design needs them and the installed version supports them.
-
Validate parsing with
just --listorjust --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.


