you need to contact someone on the plugin support or Anthropic!

The plugin is built by Firefox...It's part of the sidebar.

Hi Naviathan,

To my knowledge, there's no additional plugin associated with the sidebar. If you have trouble logging in from the sidebar, try to login to Claude from a normal window. If you still can't log in from a normal window, please share a screenshot of the message so we can troubleshoot further.

I don't understand why so many people don't know about this feature. Settings -> General -> Browser Layout -> Show sidebar. Right click inside sidebar and select Customize Sidebar. Check AI chatbot under Firefox Tools.

This happens because Anthropic no longer uses verification codes or passwords—only magic-link emails—so third-party plugins that expect a code can’t complete the login flow. The AI Chatbots sidebar can’t open or follow the magic link, so Claude sign-in simply won’t work there. The only fix is to use Claude directly in its supported interfaces (Anthropic’s site or official integrations) or ask the plugin developer to add support for magic-link authentication, since it can’t be done on the user side.

Hi Naviathan, if you are already signed into Claude in a regular tab, do you still need to sign in separately in the chatbot sidebar? Firefox does isolate cookies in some places (such as address bar search engine suggestions), but when I test with ChatGPT, the login from the regular tab carries over to the sidebar.

Hi Naviathan, if you are already signed into Claude in a regular tab, do you still need to sign in separately in the chatbot sidebar? Firefox does isolate cookies in some places (such as address bar search engine suggestions), but when I test with ChatGPT, the login from the regular tab carries over to the sidebar.

Yes, you do still need to be signed in separately in the ChatBot sidebar. I know the ChatGPT login works, but not the Claude login.

This happens because Anthropic no longer uses verification codes or passwords—only magic-link emails—so third-party plugins that expect a code can’t complete the login flow. The AI Chatbots sidebar can’t open or follow the magic link, so Claude sign-in simply won’t work there. The only fix is to use Claude directly in its supported interfaces (Anthropic’s site or official integrations) or ask the plugin developer to add support for magic-link authentication, since it can’t be done on the user side.

Well since the ChatBot plugin for the sidebar is a FireFox tool that comes with the sidebar feature, I assume it's developed by FireFox, hence the reason I'm posting in the Mozilla support forum.

Hmm, I don't know why ChatGPT and Claude work differently when it comes to how your login is handled between web pages and the sidebar. Strange.

When I search for a bug report, I find "Claude sidebar signin asks for a code, email does not come with a code." A comment there says:

For me the login link I received by email led me to a webpage containing a 6 digit code, which I then copypasted in the sidebar. It worked, but yeah, very unintuitive ...

Is that your experience with the link as well?

Hmm, I don't know why ChatGPT and Claude work differently when it comes to how your login is handled between web pages and the sidebar. Strange. When I search for a bug report, I find "Claude sidebar signin asks for a code, email does not come with a code." A comment there says:

For me the login link I received by email led me to a webpage containing a 6 digit code, which I then copypasted in the sidebar. It worked, but yeah, very unintuitive ...

Is that your experience with the link as well?

Unfortunately no, I don't get the code. I saw that post as well.