Alright, let's get started with setting up Supabase and MobX for state management. First things first, we need to install some packages. Just run this command in your terminal:

npm install mobx mobx-react-lite supabase supabase-react

Next up, we need to set up Supabase. Head over to Supabase.io, create an account if you don't have one, and start a new project. Once that's done, grab your SUPABASE_URL and SUPABASE_PUBLIC_ANON_KEY. You'll need these for your app.

Now, let's create a Supabase client. Make a new file called supabaseClient.js and add this code:

import { createClient } from '@supabase/supabase-js'

export const supabase = createClient(
  process.env.NEXT_PUBLIC_SUPABASE_URL,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY,
)

You might need to replace process.env.NEXT_PUBLIC_SUPABASE_URL and process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY with your actual Supabase URL and anon key if you're not using environment variables.

Before we dive into state management, let's initialize a MobX store. Create a new file named store.js and add this code:

import { makeAutoObservable } from "mobx"

class Store {
  constructor() {
   makeAutoObservable(this)
  }
  
  // your state goes here
}
export default Store

Now, let's use this MobX Store in your components. Import Store into your component and wrap your component with the observer HOC (High Order Component). Here's a simple example:

import Store from './store'
import { observer } from 'mobx-react-lite'

const MyComponent = observer(() => {
  const store = React.useContext(Store)
  
  // use store.state here
})

export default MyComponent

Finally, let's combine Supabase with your MobX store. Import the Supabase client into your MobX store and call Supabase methods as needed. Check out this example:

import { makeAutoObservable } from "mobx"
import { supabase } from './supabaseClient.js'

class Store {
  constructor() {
   makeAutoObservable(this)
  }

  // Getting data from Supabase database
  fetchData = async () => {
    let { data: items, error } = await supabase
      .from('items')
      .select('*')
  }
}
export default Store

After that, you can use this fetchData function in your components to load data from Supabase and use it in your state. Don't forget to wrap your component with observer to keep track of state changes.