Claude Code /login: Re-authenticate Right Away When Login Drops

It's jarring when Claude Code suddenly stops mid-work saying "login required." You wonder if you did something wrong, but mostly it's just that authentication expired and dropped. At times like this, instead of closing and reopening the terminal, the command that lets you log back in right there is /login.

Definition (What It Is)

/login is a command that logs you into your Anthropic account.

To use Claude Code, you need authentication that confirms who you are. You log in once when first installing, but over time that authentication expires for security. Then you need to log in again, and /login does exactly that. You can re-authenticate immediately, even in the middle of a session (one work span of running Claude Code).

How to Use It (By Difficulty)

Basic — Logging Back In

Type it.

/login

This starts the login procedure. Usually a browser opens to proceed with account authentication, and when done you return to Claude Code to continue your work. Just follow the on-screen guidance.

Intermediate — Recognizing the Signs of Dropped Auth

The following situations likely mean authentication has dropped.

• A notice like "login required" appears.
• A request that worked fine is suddenly rejected with an auth-related message.

In such cases, try /login before touching anything else. It usually solves it.

Advanced — Using It for Account Switching

Login is used not only to refresh authentication but also when switching the account you use.

1. First, leave the current account with /logout.
2. Log into the other account with /login.

If you split a personal account and a work account, switch with this flow. However, since the authentication info handled during login is sensitive, on a shared PC be sure to log out when done.

Common Pitfalls

• If the browser doesn't open automatically during login, just follow the guidance shown on screen (an address or code) to proceed manually.
• Authentication info is sensitive. Don't share the codes or links shown on screen with others.
• In a company network or firewall environment, the auth connection may be blocked. If it keeps failing, check your network environment.

Real-World Example

A beginner developer worked all afternoon, and around evening requests suddenly started getting rejected. At first they thought the tool was broken and closed and reopened the terminal, but it turned out authentication had expired. One /login re-authenticated them and they picked up work right away. After that, when this message appears, they don't panic and just type /login immediately.

Taking It Further

Login travels in a pair with logout. When finishing work or stepping out of a shared environment, leave the account safely with /logout. If you need other actions related to account authentication, look at the auth-related commands together.

Summary

/login is a command that logs you into your Anthropic account, re-authenticating right there when auth drops mid-work. When an auth-related message appears, think of /login first before touching anything else. Authentication info is sensitive, so don't forget to log out when done in a shared environment.

Based on: Claude Code v2.1.154 (2026.05)