Supabase Integration Guide

Use Passage to add authentication to your site built with Supabase.

This guide steps through building a Next.js application with Passage and Supabase. We will use Passage to authenticate users and manage tokens, while using Supabase for storing data and enforcing authorization logic using Row Level Security policies.

The full code example for this guide can be found here.

Passage is a passwordless authentication platform that makes is simple for developers to add passkey authentication to their apps and websites.

Next.js is a web application framework built on top of React. We will be using it for this example, as it allows us to write server-side logic within our application. Passage’s frontend elements and Node.js SDK are designed to work for Next.js.

For this guide, you will need a Passage account which can be created here, and a Supabase account which can be created here.

1. Create a Passage application

In the Passage Console, create a new application with the following configuration:

Application name: Todo Application
Authentication origin: http://localhost:3000
Redirect URL: /dashboard

2. Create and configure a Supabase project

Create a new project

In the Supabase dashboard, click New Project.

Enter a name for your project and create a secure database password.

Create a table schema

We are building Todo list application, similar to the Supabase demo application so we will need a table for the todo list items.

Create a new table in the Table Editor view
Set the Name field to “todo”
Select Enable Row Level Security (RLS)
Create two new columns
- title as text
- user_id as text with a default value of auth.user_id()
- is_complete as bool with a default value of false
Click Save to create the table

Add initial data to table

From the Table editor, select the todo table and click Insert row. Fill out the required fields with an example todo item, leaving the user_id as NULL and click Save.

After adding a few todo items, the table editor view will look like this:

3. Build a Next.js app

Create Next App

Create a new Next.js project on the command line. You can choose your settings through the setup wizard - for this guide we will use JavaScript instead of TypeScript. This example uses the create script in Next v13.2.

npx create-next-app <name-of-project>
cd <name-of-project>/

You should be able to use the default settings for the project, but here are the settings used for the example app.

Configure your ENV Create a .env file and enter the following values.

NEXT_PUBLIC_PASSAGE_APP_ID=get-from-passage-settings
PASSAGE_API_KEY=get-from-passage-settings
NEXT_PUBLIC_SUPABASE_URL=get-from-supabase-dashboard
NEXT_PUBLIC_SUPABASE_ANON_KEY=get-from-supabase-dashboard
SUPABASE_JWT_SECRET=get-from-supabase-dashboard

The Supabase values can be found under Project->Settings->API Settings

The Passage values can be found under General->Settings and General->API Keys

The PASSAGE_API_KEY and SUPABASE_JWT_SECRET are secret values and should never be shared publicly. They will only be used in the server-side code of the Next.js application.

Restart your Next.js development server to read in the environment variables.

npm run dev

Add Passage Element

Install the @passageidentity/passage-elements package.

npm install @passageidentity/passage-elements

Create a new folder called components with a new login file components/login.js and add the following content.

import { useEffect } from 'react';

const PassageLogin = () => {

    useEffect(()=>{
        require('@passageidentity/passage-elements/passage-auth');
    }, []);

    return (
        <>
          <passage-auth app-id={process.env.NEXT_PUBLIC_PASSAGE_APP_ID}></passage-auth>
        </>
      )
  }
  
  export default PassageLogin

Then update pages/index.js to include the login component.

import styles from '@/styles/Home.module.css'
import PassageLogin from '@/components/login'


export default function Home(props) {
    return(
      <div className={styles.main}>
        <PassageLogin />
      </div>
    ) 
}

When we have a successful registration the Passage element will request a redirect to '/dashboard' due to the app settings we set app creation above. Create a new file pages/dashboard.js for this new route with the following content:

import styles from '@/styles/Home.module.css'

export default function Dashboard({isAuthorized, userID, todos}) {    
    return(
       <div className={styles.main}>
        <div className={styles.container}>
          <p>
            You've logged in! 
          </p>
        </div>
      </div>
    )
}

Now when you visit http://localhost:3000 in a browser you will have a fully functioning and passwordless login page!

Go ahead and go through the registration process. You will be able to register an account with either a passkey or a magic link. Once you've logged in, you will notice that you just get redirected to /dashboard page.

The login was successful, but we need to build in the functionality to know when a user is authenticated and show them the appropriate view.

Use Passage to verify the JWT

Now we will need to use a Passage SDK to verify the JWT from Passage.

Install the Passage Node.js library.

npm install @passageidentity/passage-node

Create a utils folder and a file called utils/passage.js with the following content.

import Passage from '@passageidentity/passage-node';

const passage = new Passage({
    appID: process.env.NEXT_PUBLIC_PASSAGE_APP_ID,
    apiKey: process.env.PASSAGE_API_KEY,
});

export const getAuthenticatedUserFromSession = async (req, res) => {
    try {
        const userID = await passage.authenticateRequest(req);
        if (userID) {
          return {isAuthorized: true, userID: userID};
        }
      } catch (error) {
        // authentication failed
        return {isAuthorized: false, userID: ''};
      }
}

This will be used in the getServerSideProps() function to check authentication status for a user. Add this function to index.js then update the Home function to use the props.

import styles from '@/styles/Home.module.css'
import PassageLogin from '@/components/login'
import { getAuthenticatedUserFromSession } from '@/utils/passage'
import { useEffect } from 'react'
import Router from 'next/router';

export default function Home({isAuthorized}) {
  useEffect(()=> {
    if(isAuthorized){
      Router.push('/dashboard')
    }
  })
  
    return(
      <div className={styles.main}>
        <PassageLogin />
      </div>
    ) 
}


export const getServerSideProps = async (context) => {
  const loginProps = await getAuthenticatedUserFromSession(context.req, context.res)
    return {
      props: {
        isAuthorized: loginProps.isAuthorized?? false,
        userID: loginProps.userID?? ''
      },
    }
}

We will also use this logic on the dashboard page to check if a user is authenticated. If not we should redirect them to the login page. We will also add a quick sign out button using Passage while we are at it.

// pages/dashboard.js
import styles from '@/styles/Home.module.css'
import { useEffect } from 'react';
import Router from 'next/router';
import { getAuthenticatedUserFromSession } from '@/utils/passage'
import { PassageUser } from '@passageidentity/passage-elements/passage-user'

export default function Dashboard({isAuthorized, userID}) {
    useEffect(() => {
      if(!isAuthorized){
        Router.push('/');
      }
    })
    
    const signOut = async ()=>{
        new PassageUser().signOut()
        Router.push('/')
    }
    
    return (
      <div className={styles.main}>
        <h1>
          Welcome {userID}!{' '}
        </h1>
        <br></br>
        <button onClick={signOut}>Sign Out</button>
      </div>
    )
  }

export const getServerSideProps = async (context) => {
    const loginProps = await getAuthenticatedUserFromSession(context.req, context.res)

    return {
        props: {
          isAuthorized: loginProps.isAuthorized?? false,
          userID: loginProps.userID?? '',
        },
      }
}

The app can now tell the difference between an authenticated and unauthenticated user. When you log into the application, you will be redirected to the dashboard and see this message.

5. Integrate Supabase into Next.js app

Passage and Supabase do not currently allow for custom signing secrets. Therefore, we will need to extract the necessary claims from the Passage JWT and sign a new JWT to send to Supabase.

Because of the sensitive nature of this functionality, we will handle the authentication and JWT exchange in Next.js’s server-side rendering function getServerSideProps(). Imports used in this function will not be bundled client-side. Additionally, the JWT provided by Passage is stored in a cookie which is automatically passed to getServerSideProps().

Sign Passage token for Supabase

Install the Supabase client SDK and the popular Node package jsonwebtoken, which allows us to easily work with JWTs.

npm install @supabase/supabase-js jsonwebtoken

Create a new file called utils/supabase.js and add the following content. This function accepts a Passage user ID and then creates and signs a Supabase JWT for that user. This allows Supabase to verify the token and authenticate the user when making Supabase calls.

// utils/supabase.js
import { createClient } from '@supabase/supabase-js'
import jwt from 'jsonwebtoken'

const getSupabase = (userId) => {
  const options = {}

  if (userId) {
    const payload = {
      userId,
      exp: Math.floor(Date.now() / 1000) + 60 * 60,
    }
    const token = jwt.sign(payload, process.env.SUPABASE_JWT_SECRET)

    options.global = {
        headers: {
          Authorization: `Bearer ${token}`,
        },
      }
   }

  const supabase = createClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY,
    options
  )
  return supabase
}

export { getSupabase }

Enable Row Level Security (RLS) in Supabase

To enable users to view and create their own todo items we need to write a RLS policy. Our policy will check the currently logged in user is to determine whether or not they should have access. Let's create a PostgreSQL function to extract the current user from our new JWT.

Navigate back to the Supabase dashboard, select SQL Editor from the sidebar menu, and click New query. This will create a new query called new sql snippet, which will allow us to run any SQL against our Postgres database.

Write the following and click Run.

create or replace function auth.user_id() returns text as $$
 select nullif(current_setting('request.jwt.claims', true)::json->>'userId', '')::text;
$$ language sql stable;

You should see the output Success, no rows returned. This created a function called auth.user_id() which will return the userId field of our JWT payload.

To learn more about PostgresSQL functions, check out this deep dive video

Now we can create a policy that checks whether the current user is the owner of a todo item. From the Authentication sidebar menu in Supabase, click Policies then create a new policy.

Choose For full customization create a policy from scratch and add the following.

This policy is calling the function we just created to get the currently logged in user's ID auth.user_id() and checking whether this matches the user_id column for the current todo. If it does, then it will allow the user to select it, otherwise it will deny access.

Click Review and then Save policy.

Note: To learn more about RLS and policies, check out this deep dive video.

Fetch data from Supabase

Now we can fetch data from Supabase specific to that user. We will update pages/dashboard.js to do the following:

authenticate the user using Passage
create and sign a JWT for the user with the Supabase secret
query Supabase to fetch a user’s todo list items

// pages/dashboard.js
import styles from '@/styles/Home.module.css'
import { useEffect } from 'react';
import Router from 'next/router';
import { getAuthenticatedUserFromSession } from '@/utils/passage'
import { getSupabase } from '../utils/supabase'


export default function Dashboard({isAuthorized, userID, todos}) {
    useEffect(() => {
      if(!isAuthorized){
        Router.push('/');
      }
    })
    
    return(
        <div className={styles.main}>
          <div className={styles.container}>
            <h1>
            Welcome {userID}!{' '}
            </h1>
            <br></br>
            <button onClick={signOut}>Sign Out</button>
            <br></br>
            <div className={styles.list}>
            {todos?.length > 0 ? (
            todos.map((todo) => <li key={todo.id}>{todo.title}</li>)
          ) : (
            <p>You have completed all todos!</p>
          )}
          </div>
        </div>
      </div>
    )
  }

export const getServerSideProps = async (context) => {
    const loginProps = await getAuthenticatedUserFromSession(context.req, context.res)

    if(loginProps.isAuthorized){
        const supabase = getSupabase(loginProps.userID)
        const {data} = await supabase.from('todo').select()


        return {
            props: {
              isAuthorized: loginProps.isAuthorized?? false,
              userID: loginProps.userID?? '',
              todos: data?? [],
            },
          }
    } else {
            return {
                props: {
                    isAuthorized: loginProps.isAuthorized?? false,
                    userID: loginProps.userID?? ''
                },
            }
        }
}

When we reload our application, we are still getting the empty state for todos.

This is because we enabled Row Level Security, which blocks all requests by default and lets you granularly control access to the data in your database.

Update the UserID Data

The last thing we need to do is update the user_id columns for our existing todos. Head back to the Supabase dashboard, and select Table editor from the sidebar. You will see that the user_id field is NULL for all of our todo items.

To get the user ID for our Passage user, go back to the Passage Console and check the Users tab.

Copy this user ID and update two of the three rows in the Supabase database to match this user ID. When you are done, the database table will look like this.

Now when we refresh the application, we will see the todo items for our user!

Bonus: Add to do items

To build out a bit more functionality in our application, we can now let users add items to their to do list. Create a file pages/api/addTodo.js with the following content.

// Next.js API route support: https://nextjs.org/docs/api-routes/introduction
import { getSupabase } from "../../utils/supabase";

export default async function handler(req, res) {
  const { userID, todo } = req.body;
  const supabase = getSupabase(userID);
  const { data, error } = await supabase
    .from("todo")
    .insert({ title: todo })
    .select()
    .single();
  if (error) return res.status(400).json(error);
  res.status(200).json(data);
}

Then update pages/dashboard.js to include a form for submitting new to do items. The complete file will look like this.

import styles from "@/styles/Home.module.css";
import { useEffect, useState } from "react";
import Router from "next/router";
import { getAuthenticatedUserFromSession } from "@/utils/passage";
import { getSupabase } from "../utils/supabase";
import { PassageUser } from "@passageidentity/passage-elements/passage-user";

export default function Dashboard({ isAuthorized, userID, initialTodos }) {
  const [todos, setTodos] = useState(initialTodos);
  useEffect(() => {
    if (!isAuthorized) {
      Router.push("/");
    }
  });

  const handleSubmit = async (e) => {
    e.preventDefault();
    const data = new FormData(e.target);
    const todo = data.get("todo");
    const res = await fetch("/api/addTodo", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({ todo, userID }),
    }).then((res) => res.json());
    setTodos([...todos, res]);
  };

  const signOut = async () => {
    new PassageUser().signOut();
    Router.push("/");
  };

  return (
    <div className={styles.main}>
      <div className={styles.container}>
        <h1>Welcome {userID}! </h1>
        <br></br>
        <button onClick={signOut}>Sign Out</button>
        <br></br>
        <div className={styles.list}>
          {todos?.length > 0 ? (
            todos.map((todo) => <li key={todo.id}>{todo.title}</li>)
          ) : (
            <p>You have completed all todos!</p>
          )}
        </div>
        <form onSubmit={handleSubmit}>
          <label>
            Todo: <input type="text" name="todo" />
          </label>
          <button>Submit</button>
        </form>
      </div>
    </div>
  );
}

export const getServerSideProps = async (context) => {
  const loginProps = await getAuthenticatedUserFromSession(
    context.req,
    context.res
  );

  if (loginProps.isAuthorized) {
    const supabase = getSupabase(loginProps.userID);
    const { data } = await supabase
      .from("todo")
      .select()
      .is("is_complete", false);

    return {
      props: {
        isAuthorized: loginProps.isAuthorized ?? false,
        userID: loginProps.userID ?? "",
        initialTodos: data ?? [],
      },
    };
  } else {
    return {
      props: {
        isAuthorized: loginProps.isAuthorized ?? false,
        userID: loginProps.userID ?? "",
      },
    };
  }
};