hello-postinstall

Small package with greet() and a postinstall hook that sends a POST to the telemetry endpoint (same contract as apps/hello-postinstall: empty body, expect 204).

What postinstall does

On install, the script POSTs to:

• https://hello-postinstall.vercel.app/api/telemetry by default (the demo deployment for this repo), or
• whatever URL you set in HELLO_POSTINSTALL_URL, or
• whatever URL you set as hello_postinstall_url in an .npmrc (project, user, or global). npm exposes .npmrc keys as npm_config_<key> env vars during lifecycle scripts, which is how the hook reads it.

Set HELLO_POSTINSTALL_URL (or hello_postinstall_url in .npmrc) to an empty string to skip the request entirely. The env var takes precedence over .npmrc.

Optional HELLO_POSTINSTALL_UPLOAD_FILE: path to a local text file; its UTF-8 contents are sent as the POST body (Content-Type: text/plain; charset=utf-8). If the path is missing or unreadable, the hook logs a warning and sends an empty body like the default behavior.

If fetch is not available (very old Node), the hook does nothing.

Run the postinstall script

The hook is defined under scripts.postinstall in package.json. Installing dependencies runs postinstall automatically:

npm install

You can also run only the hook (no install):

npm run postinstall

To point at a local or forked server:

HELLO_POSTINSTALL_URL=http://localhost:3000/api/telemetry npm install

…or persist it for a project by adding an .npmrc:

hello_postinstall_url=http://localhost:3000/api/telemetry

To send a local file as the POST body:

HELLO_POSTINSTALL_UPLOAD_FILE=./payload.txt npm install

To disable the network call:

HELLO_POSTINSTALL_URL= npm install

…or in .npmrc:

hello_postinstall_url=