Fix Background Agent Write Permissions

Background agents (run_in_background: true) can't perform write operations even when those operations are in permissions.allow. Read-only operations work fine.

This is a known bug. The workaround: use bypassPermissions mode and add hooks for safety.

The Workaround

Set agents to mode: "bypassPermissions" to skip the broken permissions layer, then use PreToolUse hooks to enforce safety rules:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [{
          "type": "command",
          "command": "bash ~/.claude/hooks/destructive-guard.sh"
        }]
      }
    ]
  }
}

Hooks fire regardless of permission mode — they run at the process level and cannot be bypassed by the model.

Install Safety Hooks

npx cc-safe-setup

892 example hooks. 213 test files.

cc-safe-setup · 892 example hooks · 213 test files · GitHub