What is the difference between prepare and prepublishOnly?

prepublishOnly runs only on npm publish, never on local installs, so it is ideal for publish-only guards like running tests. prepare runs on publish, on local npm install with no args, and on git-dependency installs, making it the right place for build steps that consumers need.

In what order do install hooks run?

On npm install the order is preinstall, then dependencies are installed, then install, then postinstall, then prepare. pre and post wrappers always bracket the matching script automatically.

What hooks does npm publish fire?

prepublishOnly runs first, then the pack chain prepack and prepare, then postpack once the tarball exists, then publish and postpublish after the registry upload succeeds.

Do pnpm and Yarn use the same hook names?

Yes, they honour the same script names. For security, pnpm v7+ ignores preinstall, install and postinstall scripts of dependencies unless you allow-list them, so do not rely on a dependency's postinstall under pnpm.

How do pre and post wrappers work?

For any script x, npm automatically runs prex before it and postx after it when those scripts exist. This applies to your own custom scripts too, so a test script can have a pretest and posttest.

npm/pnpm Lifecycle Hooks Reference

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npm lifecycle hooks in execution order

npm runs a defined set of lifecycle scripts at known points during install, pack, publish and version operations. Knowing the exact order — and which command triggers which hook — lets you place build steps, guards and release automation in the right package.json field. This reference groups every hook by its triggering command and shows the precise sequence, with a live filter.

How it works

Each script is a named field under scripts in package.json. For any script x, npm automatically wraps it with prex and postx when those exist:

{
  "scripts": {
    "preinstall": "node check-node-version.js",
    "prepare": "tsc -p .",
    "prepublishOnly": "npm test",
    "postversion": "git push --follow-tags"
  }
}

On npm install the order is preinstall → dependency install → install → postinstall → prepare. On npm publish the chain is prepublishOnly → prepack → prepare → postpack → publish → postpublish.

Tips and notes

Put build output that consumers need in prepare — it runs on publish and on git-dependency installs.
Use prepublishOnly for tests and lint gates that should run only at publish.
postversion is the conventional place to push tags after npm version.
pnpm v7+ skips dependency install hooks for safety; allow-list any you trust.