dev

dev uses pkgx and shellcode to automatically, install and activate the packages you need for different projects as you navigate in your shell.

Ensure you are using the same versions of tools for your entire stack, during dev, across your team and in production.

Note

Packages are installed to ~/.pkgx and not available to your wider system without using a tool from the pkgx tooling ecosystem.

Getting Started

Since dev v1.8.0 we integrate with pkgm (^0.11) and this is the recommended way to use dev.

Important

Both dev and the packages you want to be dev-aware must be installed to /usr/local/ for this to work. (dev (but only dev) can be a pkgm shim).

sudo pkgm install dev node@22

$ cd my-project
$ ls
package.json

$ node --version
command not found: node

$ sudo pkgm install dev node
$ node --version && which node
v23.11.0
/usr/local/bin/node

$ cat package.json | jq .engines
{
  "node": "^20"
}

$ dev .
activated `~/my-project` (+node^20)

$ node --version && which node
v20.19.0
/usr/local/bin/node

$ cd ..
$ node --version && which node
v23.11.0
/usr/local/bin/node

$ cd -
$ node --version && which node
v20.19.0
/usr/local/bin/node

pkgm installs dev-aware packages to /usr/local/bin. Provided you have /usr/local/bin/dev installed and you have activated dev in your project directories the node that is invoked is swapped out when invoked.

This is the recommended way to use dev because it works everywhere and not just the terminal.

dev via Shellcode

Using dev via shellcode requires hooks to be installed in your shell. It is handy in that no tool needs to be installed. It is problematic in that shell hooks are more invasive and don’t work in other tools like editors.

---

Using dev via shellcode…

A great advantage of the shellcode is not needing to install tools you may never need again when exploring new open source projects.

pkgx dev integrate

dev requires pkgx but at your preference:

brew install pkgxdev/made/dev
dev integrate

We support macOS & Linux, Bash & Zsh. PRs are very welcome to support more shells.

[!NOTE]

dev integrate looks for and edits known shell.rc files adding one line:

eval "$(dev --shellcode)"

If you don’t trust us (good on you), then do a dry run first:

pkgx dev integrate --dry-run

If you like, preview the shellcode: pkgx dev --shellcode. This command only outputs shellcode, it doesn’t modify any files or do anything else either.

Usage

$ cd my-project

my-project $ ls
package.json

my-project $ dev
+nodejs.org
# ^^ installs node to ~/.pkgx/nodejs.org/v22.12.0 if not already installed

my-project $ node --version
v22.12.0

$ which node
~/.pkgx/nodejs.org/v22.12.0/bin/node

$ cd ..
-nodejs.org

$ node
command not found: node

[!TIP]

Try Before You vi

Modifying your shell.rc can be… intimidating. If you just want to temporarily try dev out before you :wq—we got you:

$ cd my-project
$ eval "$(pkgx dev)"
+deno^2
$ deno --version
deno 2.1.1

The devenv will only exist for the duration of your shell session.

---

How Packages are Determined

• We look at the files you have and figure out the packages you need.
• Where possible we also determine the versions you need if such things can be determined by looking at configuration files.

Specifying Versions

We allow you to add YAML front matter to all files to specify versions more precisely:

# ---
# pkgx:
#   dependencies:
#     openssl.org: 1.1.1n
# ---

[package]
name = "my cargo project"
# snip…

We allow more terse expressions including eg:

# ---
# pkgx:
#   dependencies: [email protected] deno^2 npm
# ---

The major exception being json since it doesn’t support comments, in this case we read a special pkgx node:

{
  "pkgx": {
    "dependencies": {
      "openssl.org": "1.1.1n",
      "deno": "^2",
      "npm": null
    }
  }
}

You can also make a pkgx.yaml file.

Adding Custom Environment Variables

You can add your own environment variables if you like:

# ---
# pkgx:
#   dependencies:
#     openssl.org: 1.1.1n
#   env:
#     MY_VAR: my-value
# ---

Note

• Adding environment variables only works via the shellcode route.
• The environment variable's value is sanitized, so expressions like MY_VAR: $(sudo rm -rf --no-preserve-root /) will throw an error.
• We recommend direnv instead of this route.

dev & Editors

The sure fire way for things to work in editors is to use the dev/pkgm combo. Having said this most editors if opened via the Terminal will inherit that Terminal’s environment.

GitHub Actions

- uses: pkgxdev/dev@v1

Our action installs needed packages (via pkgx) and sets up the environment the same as dev does in your terminal.

Contributing

We use deno, so either install that or—you know—type dev.

Edit ./src/sniff.ts to add new dev types.