laurigates When to Use This Skill
| Use this skill when... | Use justfile-expert instead when... |
|---|---|
| Installing packages without picking a manager up front | Defining a project-local just install recipe |
One-off --global or --dev installs across mixed projects |
Standardising just deps / just sync for a team |
| Auto-detecting between uv, bun, npm, cargo, and go | The repo already exposes installation as a recipe |
| Use this skill when... | Use shell-expert instead when... |
|---|---|
| The user just wants the install command run | Writing a custom installer script with retries or branching |
| Syncing the lockfile via the right native subcommand | Composing multi-package-manager bootstrap logic in shell |
Context
- Package files: !
find . -maxdepth 1 \( -name "package.json" -o -name "pyproject.toml" -o -name "requirements.txt" -o -name "Cargo.toml" -o -name "go.mod" -o -name "Gemfile" \) -type f - Lock files: !
find . -maxdepth 1 \( -name "uv.lock" -o -name "package-lock.json" -o -name "yarn.lock" -o -name "pnpm-lock.yaml" -o -name "Cargo.lock" -o -name "go.sum" \) -type f
Parameters
Parse $ARGUMENTS and bind these before running anything. They are supplied by
the caller; nothing substitutes them for you.
Token in $ARGUMENTS |
Binds | Default when absent |
|---|---|---|
| Non-flag tokens | PACKAGES — space-separated package names |
empty → install everything from the manifest |
--dev |
DEV — add to development dependencies |
off |
--global |
GLOBAL — install globally rather than into the project |
off |
Every command below is written with a literal PACKAGES placeholder — substitute
the bound value when you run it.
Execution
Run this install:
Step 1: Detect the package manager
Read the Lock files and Package files lines from Context above. Lock files
win — they name the manager that actually produced the current install; a
manifest alone only narrows the ecosystem.
| Signal (repo root) | PACKAGE_MANAGER |
|---|---|
uv.lock, or pyproject.toml with a [tool.uv] section |
uv |
bun.lock / bun.lockb |
bun |
pnpm-lock.yaml |
pnpm |
yarn.lock |
yarn |
package-lock.json |
npm |
Cargo.lock / Cargo.toml |
cargo |
go.sum / go.mod |
go |
pyproject.toml / requirements.txt with no lock file |
uv |
package.json with no lock file |
bun (this portfolio's default — see bun-package-manager) |
- Several matches in one repo (a polyglot monorepo) → run the matching row for each ecosystem, then report them together.
- No match → report that no manifest was found and stop; do not guess.
Step 2: Run the row for the detected manager
| PACKAGE_MANAGER | Install all (no PACKAGES) |
Add PACKAGES |
With --dev |
With --global |
|---|---|---|---|---|
uv |
uv sync |
uv add PACKAGES |
uv add --dev PACKAGES |
uv tool install PACKAGES |
bun |
bun install |
bun add PACKAGES |
bun add -d PACKAGES |
bun add -g PACKAGES |
npm |
npm ci (lock present) else npm install |
npm install PACKAGES |
npm install -D PACKAGES |
npm install -g PACKAGES |
yarn |
yarn install --frozen-lockfile |
yarn add PACKAGES |
yarn add -D PACKAGES |
yarn global add PACKAGES |
pnpm |
pnpm install --frozen-lockfile |
pnpm add PACKAGES |
pnpm add -D PACKAGES |
pnpm add -g PACKAGES |
cargo |
cargo build |
cargo add PACKAGES |
cargo add --dev PACKAGES |
cargo install PACKAGES |
go |
go mod download |
go get PACKAGES |
(Go has no dev-dependency tier) | go install PACKAGES@latest |
For Python without uv, uv pip install -r requirements.txt installs a legacy
requirements file without migrating the project.
System Dependencies
Check for system-level dependencies:
- macOS: Use Homebrew if Brewfile exists
- Linux: Detect package manager (apt, yum, dnf, pacman)
Lock File Management
After installation:
- Verify lock file is updated
- If new lock file created, remind to commit it
- Check for security vulnerabilities
Post-install Actions
- Display installed packages and versions
- Run
/lint:checkto ensure code quality - Run
/test:runto verify nothing broke - Suggest
/git:smartcommitif lock files changed