Supabase is an open source Firebase alternative. Start your project with a Postgres database, Authentication, instant APIs, Edge Functions, Realtime subscriptions, and Storage.

Supabase

okey so after hours of trying I solved in this way <:Prayge:878367590387421305> 
```jsx
  useEffect(() => {
    console.log('added listener')

    const previousSubscriptions = supabase.getSubscriptions()

    if (previousSubscriptions.length > 0) return // <--- THIS

    const listener = supabase
      .from('metrics')
      .on('INSERT', handleNewInsert)
      .subscribe((status) => {
        console.log({ status })
      })

    return () => {
      supabase.removeSubscription(listener)
    }
  }, [])
```