Dynamic Package Runner (amber x / amber dlx)

1. What is amber x / amber dlx?

Similar to npx or bunx, amber x (aliased as amber dlx) lets developers run CLI executables from remote npm packages without running npm install, without polluting project node_modules, and without modifying package.json.

Unlike traditional tools, amber x is implemented natively in Rust with three key optimizations:

1. Concurrent Streaming Download & Unpack: Directly streams tarballs from the registry and extracts to cache via fast async pipelines.
2. Content-Addressable Global Cache: Cached under ~/.amber/x_cache. Consecutive runs of the same version execute in sub-millisecond time.
3. Native V8 Execution & Sandboxing: Inspects the bin field of package.json and runs directly on amber run, with support for timeout and memory caps.

2. Command Syntax & Examples

# Basic syntax
amber x <package-specifier> [arguments...]

# The dlx alias is also supported
amber dlx cowsay "Hello Amber!"

Specifying Versions & Scopes

# 1. Run the latest version
amber x cowsay "Hello Amber!"

# 2. Specify exact version
amber x prettier@3.2.5 --write "src/**/*.ts"

# 3. Scoped packages
amber x @biomejs/biome check ./src

# 4. Multi-binary packages
amber x typescript tsc --init

3. Sandboxing & CLI Options

amber x inherits the Amber security philosophy, allowing safe execution of untrusted scripts:

# Cap execution time to 10 seconds
amber x --timeout 10000 untrusted-script

# Cap V8 heap memory to 128MB
amber x --max-memory 134217728 heavy-cli-tool

# Bypass local cache and fetch latest
amber x --no-cache cowsay "Always Fresh"

CLI Flag Reference

4. CI/CD Pipeline Benefits

In GitHub Actions or containerized build pipelines, amber x eliminates heavy npm install steps, reducing one-off tool runs and scaffolding setup times from tens of seconds to hundreds of milliseconds:

# Direct tool invocation in CI
amber x eslint src/
amber x rimraf dist/