Comment by AnotherGoodName

Add this to .claude/settings.json:

  {                                                                                                                                                              
    "sandbox": {                                                                                                                                               
      "enabled": true,
      "filesystem": {
        "allowRead": ["."],
        "denyRead": ["~/"],
        "allowWrite": ["."],
        "denyWrite": ["/"]
      }                                                                                                                                                          
    }
  }

You can change the read part if you're ok with it reading outside. This feature was only added 10 days ago fwiw but it's great and pretty much this.