Run npm login for the correct registry, then retry the install or publish command.
Updated
Verification status
General troubleshooting guidance
Evidence
0 public source URLs
Before you change production
This page does not expose source URLs in the page body. Treat it as general troubleshooting guidance and verify against official documentation before changing systems.
Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for npm, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.
What this error means
npm ERR! code E401 means npm reached a registry that requires authentication, but the current credentials were missing, expired, or rejected.
Common causes
Your npm token expired or was revoked.
The project uses a private package scope and the matching registry is not configured.
.npmrc contains an old token, wrong registry URL, or malformed auth line.
Publishing requires two-factor authentication and the command did not include an OTP.
Quick fixes
Check which registry npm is using:
npm config get registry
Log in again:
npm login
If the package uses a scope, verify the scoped registry:
npm config get @your-scope:registry
Retry the original command.
Step-by-step troubleshooting
Run npm whoami to confirm whether npm sees a valid logged-in user.
Inspect project and user .npmrc files for stale registry or token entries.
Confirm that private package scopes point to the correct registry host.
For publishing, add the OTP when your npm account requires two-factor authentication.
If CI fails, rotate the npm token and update the CI secret value.
Diagnostic flow for this page
Match npm ERR! code E401 exactly before applying the quick fix.
Compare the failing environment with npm versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.