Documentation for just and justfile. This skill should be used before editing justfile or running just commands. TRIGGER when run just command, or edit justfile; or when about to write any `just ...` shell invocation in Bash, pueue, or scripts.
Standardmäßig ist der Prompt ausgewählt, der zuerst die Quelle prüft. Sie können zu einem direkten Befehl wechseln oder eine lokale Kopie herunterladen.
Quelldateien prüfen
Lesen Sie SKILL.md und alle von SkillsMP angezeigten Begleitdateien, bevor Sie sich für eine Installation entscheiden.
Mit Codex oder Claude installieren Kopieren Sie diesen Prompt, fügen Sie ihn in Codex, Claude oder einen anderen Assistant ein und lassen Sie die Skill-Seite prüfen und installieren.
Ein direkter Befehl überspringt den Prüf-Prompt. Prüfen Sie die Quelle, bevor Sie ihn ausführen.
Documentation for just and justfile. This skill should be used before editing justfile or running just commands. TRIGGER when run just command, or edit justfile; or when about to write any `just ...` shell invocation in Bash, pueue, or scripts.
Just Command Runner
Overview
Expert guidance for Just, a command runner with syntax inspired by make. Use this skill for creating justfiles, writing recipes, configuring settings, and implementing task automation workflows.
Key capabilities:
Create and organize justfiles with proper structure
Write recipes with attributes, dependencies, and parameters
Configure settings for shell, modules, and imports
Use built-in constants for terminal formatting
Implement check/write patterns for code quality tools
Quick Reference
Essential Settings
set allow-duplicate-recipes # Allow recipes to override imported ones
set allow-duplicate-variables # Allow variables to override imported ones
set shell := ["bash", "-euo", "pipefail", "-c"] # Strict bash with error handling
set unstable # Enable unstable features (modules, script attribute)
set dotenv-load # Auto-load .env file
set positional-arguments # Pass recipe args as $1, $2, etc.
Common Attributes
Attribute
Purpose
[arg("p", long, ...)]
Configure parameter as --flag option (v1.46)
[group("name")]
Group recipes in just --list output
[no-cd]
Don't change to justfile directory
[private]
Hide from just --list (same as _ prefix)
[script]
Execute recipe as single script block
[script("interpreter")]
Use specific interpreter (bash, python, etc.)
[confirm("prompt")]
Require user confirmation before running
[doc("text")]
Override recipe documentation
[positional-arguments]
Enable positional args for this recipe only
Recipe Argument Flags (v1.46.0+)
The [arg()] attribute configures parameters as CLI-style options:
# Long option (--target)
[arg("target", long)]
build target:
cargo build --target {{ target }}
# Short option (-v)
[arg("verbose", short="v")]
run verbose="false":
echo "Verbose: {{ verbose }}"
# Combined long + short
[arg("output", long, short="o")]
compile output:
gcc main.c -o {{ output }}
# Flag without value (presence sets to "true")
[arg("release", long, value="true")]
build release="false":
cargo build {{ if release == "true" { "--release" } else { "" } }}
# Help string (shown in `just --usage`)
[arg("target", long, help="Build target architecture")]
build target:
cargo build --target {{ target }}
Usage examples:
just build --target x86_64
just build --target=x86_64
just compile -o main
just build --release
just --usage build # Show recipe argument help
Terminal formatting constants are globally available (no definition needed):
Constant
Description
CYAN, GREEN, RED, YELLOW, BLUE, PURPLE
Text colors
BOLD, ITALIC, UNDERLINE, STRIKETHROUGH
Text styles
NORMAL
Reset formatting
BG_*
Background colors (BG_RED, BG_GREEN, etc.)
HEX, HEXLOWER
Hexadecimal digits
Usage:
@status:
echo -e '{{ GREEN }}Success!{{ NORMAL }}'
echo -e '{{ BOLD + CYAN }}Building...{{ NORMAL }}'
Key Functions
# Require executable exists (fails recipe if not found)
jq := require("jq")
# Get environment variable with default
log_level := env("LOG_LEVEL", "info")
# Get justfile directory path
root := justfile_dir()
Recipe Patterns
Status Reporter Pattern
Display formatted status during multi-step workflows:
@_run-with-status recipe *args:
echo ""
echo -e '{{ CYAN }}→ Running {{ recipe }}...{{ NORMAL }}'
just {{ recipe }} {{ args }}
echo -e '{{ GREEN }}✓ {{ recipe }} completed{{ NORMAL }}'
alias rws := _run-with-status
Check/Write Pattern
Pair check (verify) and write (fix) recipes for code quality tools:
[group("checks")]
@biome-check +globs=".":
na biome check {{ globs }}
alias bc := biome-check
[group("checks")]
@biome-write +globs=".":
na biome check --write {{ globs }}
alias bw := biome-write
Full Check/Write Pattern
Aggregate all checks with status reporting:
[group("checks")]
@full-check:
just _run-with-status biome-check
just _run-with-status prettier-check
just _run-with-status tsc-check
echo ""
echo -e '{{ GREEN }}All code checks passed!{{ NORMAL }}'
alias fc := full-check
[group("checks")]
@full-write:
just _run-with-status biome-write
just _run-with-status prettier-write
echo ""
echo -e '{{ GREEN }}All code fixes applied!{{ NORMAL }}'
alias fw := full-write
Standard Alias Conventions
Recipe
Alias
Recipe
Alias
full-check
fc
full-write
fw
biome-check
bc
biome-write
bw
prettier-check
pc
prettier-write
pw
mdformat-check
mc
mdformat-write
mw
tsc-check
tc
ruff-check
rc
test
t
build
b
Inline Scripts
Just supports inline scripts in any language via two methods:
Script Attribute (Recommended)
Use [script("interpreter")] for cross-platform compatibility:
[script("node")]
fetch-data:
const response = await fetch('https://api.example.com/data');
const data = await response.json();
console.log(data);
[script("python3")]
analyze:
import json
with open('package.json') as f:
pkg = json.load(f)
print(f"Package: {pkg['name']}@{pkg['version']}")
[script("bash")]
deploy:
set -e
npm run build
aws s3 sync dist/ s3://bucket/
Shebang Method
Use #!/usr/bin/env interpreter at the recipe start:
