I use Claude Code every day on my main PC. It’s the tool I talk to when making apps for my family. It worked well without problems for several weeks.

Then I wanted to use it on a second device. This is my daughter’s PC. Sometimes I work on her apps there. Same subscription, same account, everything was the same. I installed the VS Code extension and opened it. Then I saw this error:

API Error: 401 Invalid authentication credentials

That was the start of about 90 minutes I wish I could get back.

What I Tried First (Nothing Worked)

The Claude chatbot suggested the problem was an environment variable. It was showing an old API key. I opened the terminal. I saw that ANTHROPIC_API_KEY was indeed set. I deleted it and restarted. The same error happened again.

Next, I searched for the error and tried other things I found:

  • I deleted the %USERPROFILE%\.claude folder. No change.
  • I checked Windows Credential Manager for anything labeled “claude” or “anthropic”. There was nothing.
  • I uninstalled the VS Code extension and reinstalled it from scratch.

That last method looked promising. I thought a clean install would clear everything. But the extension seemed to remember the same broken state. The same error showed up again.

I also tried running claude logout and claude login in the terminal. Both commands put me into Claude’s interactive chat mode. They did not do anything helpful. I didn’t know what to do, so I closed it and kept searching.

I tried to find a “Sign Out” option in VS Code’s command palette. It wasn’t there in the version I was running.

I checked the VS Code extension logs. (You press Ctrl+Shift+U, then choose “Claude Code” from the dropdown.) All it said was this:

AuthManager initialized
Claude code extension is now active

And then nothing. No login flow. No error details. Just silence.

How I Actually Fixed the Problem

The solution was to use the same command I had already tried, but in a slightly different way.

Running claude logout by itself put me into interactive chat mode. It treated “logout” as a message to send, not a subcommand. Instead, this is what I had to do:

  1. Run claude without any arguments. This brings you into interactive mode on purpose.
  2. Once inside, type /logout as a slash command.
  3. Then, type /login.

At step 3, a browser window opened. I logged into my claude.ai account. Done. The VS Code extension saw this right away when I restarted it.

The difference was important. Running claude logout versus running claude first and then /logout. The first one treats “logout” as a chat message. The second one actually runs the logout action.

I don’t know why claude logout doesn’t work as a direct command. I am not a developer, so I can’t explain it at that level. I can only tell you that this sequence worked when nothing else did.

The Cost of Getting Here

I use Claude Code with a Pro subscription. It costs $20 per month. The 90 minutes I spent on this problem did not add to my costs. But it was time I could have used to build something.

If you use an API billing plan instead of a subscription, the cause of a 401 error is different. Most likely, your API key is set up incorrectly. The slash command fix I explained here is especially for users with a subscription (claude.ai Pro or Max).

Summary

If you are getting a 401 error with Claude Code in VS Code, and you have a claude.ai subscription:

  1. Open your terminal and run claude (no arguments).
  2. Inside the interactive prompt, type /logout and press Enter.
  3. Then type /login and press Enter.
  4. Complete the browser login that opens.

That’s it. It took me 90 minutes to find a 30-second solution. I am writing this so the next person can find it in under 30 seconds.

An Embarrassing User Error: SSH Connection to My NAS

Around the same time, I ran into another connection problem. This one was about SSH.

I tried to connect to my home NAS using ssh [email protected]. But I got a “Connection refused” error. I went through the usual checks:

  • DSM auto-block list — It was empty.
  • Terminal & SNMP settings — SSH was active.
  • iptables startup task — It was already running.
  • TCP port test — Ports 22, 445, and 5000 were all blocked.

I checked all of these before even thinking about running ipconfig. My laptop was connected to the wrong Wi-Fi. My home has two routers, so there are two Wi-Fi networks. I should have been on the one connected to the NAS, but I wasn’t. As soon as I changed the Wi-Fi, SSH connected right away.

If your SSH or SMB connection to a local NAS fails, check your Wi-Fi name first. Do this before changing any port or firewall settings.