npm ERR! code EUSAGE

What This Error Means

npm rejected the command usage or configuration (invalid usage).

How to Fix It

1. Run npm help <command> and confirm correct flags and argument order.
2. Print npm version: npm -v and update if you are using an old version.
3. If this started after config changes, temporarily move .npmrc aside and retry.

Why It Happens

• The command was invoked with invalid flags or arguments.
• The environment or .npmrc contains an unsupported option for your npm version.

How to Verify

1. Re-run the same command with corrected flags and confirm it completes.
2. Restore config only after confirming which setting caused the issue.

Common CLI Output

npm ERR! code EUSAGE

npm ERR! `npm ci` can only install packages when your package.json and package-lock.json are in sync.

Prevention Tips

• Pin npm versions in CI.
• Keep .npmrc minimal and documented.

Where This Can Be Triggered

      prefix += '\n\n'
    }
    return Object.assign(new Error(`\n${prefix}${this.usage}`), {
      code: 'EUSAGE',
    })
  }