Everything about your AI connection is in Settings, AI connection. Your key is stored encrypted and never shown again, so to change it you replace it.
1.Replace your key
Click Replace key, paste the new key, and click Check and replace. The new key is checked with Anthropic before the old one is swapped out, so a wrong key never breaks your assistant. Cancel leaves the current key in place.
2.Change models
Pick a model for each kind of job and click Save models.
3.Remove your key
Click Disconnect. Your assistant stops answering until you connect a key again; your notes are untouched.
4.Tidy up in Anthropic
After replacing or removing a key, delete the old one on the Claude Console's API keys page, so it cannot be used anywhere else.
5.If your assistant suddenly stops answering
The usual cause is the AI account, not Your Business Mind: credit ran out, a spending limit was reached, or the key was deleted in the Console. Check your AI costs, then replace the key if needed.