npm ERR! code E422

What This Error Means

The registry rejected the publish payload as invalid (unprocessable entity).

How to Fix It

1. Check which registry npm is using: npm config get registry.
2. If the package is scoped, verify scope registry mapping in .npmrc (example: @your-scope:registry=...).
3. Validate package.json fields (name, version, files) and ensure the package packs correctly: npm pack.
4. Check for invalid semver or forbidden characters in the package name.

Why It Happens

• The version is already published (most common).
• The package metadata is invalid or violates registry policy.
• You are publishing to the wrong registry or scope.

How to Verify

1. Run npm view <pkg>@<version> and confirm the new version exists after publish.
2. Re-run publish and confirm the registry accepts it.

Manual validation checklist

1. Preview what will be published: npm pack --dry-run (or npm pack and inspect the tarball).
2. Confirm effective registry: npm config get registry.

Common CLI Output

npm ERR! code E422

npm ERR! 422 Unprocessable Entity - PUT https://registry.npmjs.org/npm-sync - Unprocessable Entity

How npm surfaces this error

1. Registries treat versions as immutable. A version conflict is an expected protection.
2. Invalid package metadata causes publish validation errors.

Prevention Tips

• Automate version bumps as part of release workflow.
• Keep registry routing explicit for scoped packages.
• Validate package contents with npm pack before publishing.

Where This Can Be Triggered

// used by the ping and doctor commands
const npmFetch = require('npm-registry-fetch')
module.exports = async (flatOptions) => {
  const res = await npmFetch('/-/ping', { ...flatOptions, cache: false })
  return res.json().catch(() => ({}))
}