Session management in Supabase

Introduction

Session management helps keep users logged in safely. It remembers who you are while you use an app.

When you want users to stay logged in after they close the app.

When you need to check if a user is allowed to see certain pages.

When you want to log users out after some time for security.

When you want to refresh login tokens without asking users to sign in again.

Syntax

Supabase

const { data, error } = await supabase.auth.getSession()

const { data, error } = await supabase.auth.signInWithPassword({ email, password })

const { error } = await supabase.auth.signOut()

getSession() gets the current user session if logged in.

signInWithPassword() logs in a user with email and password.

Examples

Check if a user session exists and print it.

Supabase

const { data, error } = await supabase.auth.getSession()
console.log(data.session)

Log in a user with email and password.

Supabase

const { data, error } = await supabase.auth.signInWithPassword({ email: '[e-mail]', password: 'secret' })
if (data.session) {
  console.log('User logged in')
}

Log out the current user.

Supabase

const { error } = await supabase.auth.signOut()
if (!error) {
  console.log('User logged out')
}

Sample Program

This program logs in a user, checks the current session, and then logs out the user. It shows how to manage user sessions step-by-step.

Supabase

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

const supabaseUrl = 'https://xyzcompany.supabase.co'
const supabaseKey = 'public-anonymous-key'
const supabase = createClient(supabaseUrl, supabaseKey)

async function manageSession() {
  // Sign in user
  const { data: signInData, error: signInError } = await supabase.auth.signInWithPassword({
    email: '[e-mail]',
    password: 'password123'
  })
  if (signInError) {
    console.log('Sign in error:', signInError.message)
    return
  }
  console.log('Signed in:', signInData.session !== null)

  // Get current session
  const { data: sessionData, error: sessionError } = await supabase.auth.getSession()
  if (sessionError) {
    console.log('Get session error:', sessionError.message)
    return
  }
  console.log('Current session user email:', sessionData.session?.user.email)

  // Sign out user
  const { error: signOutError } = await supabase.auth.signOut()
  if (signOutError) {
    console.log('Sign out error:', signOutError.message)
    return
  }
  console.log('User signed out successfully')
}

manageSession()

Important Notes

Always handle errors to know if login or logout fails.

Sessions keep users logged in without asking for password every time.

Use secure environment variables for your Supabase keys, not hardcoded strings.

Summary

Session management keeps track of who is logged in.

Use signInWithPassword to log in and signOut to log out.

Check current session anytime with getSession.

Practice

1. What does session management in Supabase primarily help you do?

easy

A. Keep track of who is logged in

B. Store database tables

C. Manage server resources

D. Create new users automatically

Solution

1. Step 1: Understand session management purpose

   Session management is about tracking user login status.

2. Step 2: Match with Supabase context

   Supabase uses sessions to know who is logged in or out.

3. Final Answer:

   Keep track of who is logged in -> Option A

4. Quick Check:

   Session management = tracking logged-in users [OK]

Hint: Sessions track logged-in users, not data or servers [OK]

Common Mistakes:

• Confusing session with database storage
• Thinking session manages server resources
• Assuming session creates users automatically

2. Which Supabase method is used to log a user in with email and password?

easy

A. signOut

B. getSession

C. signInWithPassword

D. createUser

Solution

1. Step 1: Identify login method

   Supabase uses signInWithPassword to log users in with email and password.

2. Step 2: Eliminate other options

   signOut logs out, getSession checks session, createUser is not a Supabase method.

3. Final Answer:

   signInWithPassword -> Option C

4. Quick Check:

   Login method = signInWithPassword [OK]

Hint: Login uses signInWithPassword, logout uses signOut [OK]

Common Mistakes:

• Choosing signOut to log in
• Confusing getSession with login
• Assuming createUser is a Supabase method

3. What will the following code return if a user is logged in?

const { data } = await supabase.auth.getSession();
console.log(data.session);

medium

A. An object with session details

B. null

C. An error message

D. Undefined

Solution

1. Step 1: Understand getSession behavior

   getSession returns session info if user is logged in.

2. Step 2: Analyze console output

   Logging data.session shows session object, not null or error.

3. Final Answer:

   An object with session details -> Option A

4. Quick Check:

   Logged-in session = session object [OK]

Hint: getSession returns session object if logged in, else null [OK]

Common Mistakes:

• Expecting null when user is logged in
• Thinking getSession throws error
• Assuming undefined is returned

4. You wrote this code to log out a user:

await supabase.auth.signInWithPassword();

What is wrong here?

medium

A. You need to pass email and password to signInWithPassword

B. signInWithPassword is for logging in, not logging out

C. signInWithPassword does not exist in Supabase

D. You should use getSession to log out

Solution

1. Step 1: Identify method purpose

   signInWithPassword is for logging in users, not logging out.

2. Step 2: Correct logout method

   To log out, use signOut method instead.

3. Final Answer:

   signInWithPassword is for logging in, not logging out -> Option B

4. Quick Check:

   Logout method ≠ signInWithPassword [OK]

Hint: Use signOut to log out, not signInWithPassword [OK]

Common Mistakes:

• Using signInWithPassword to log out
• Forgetting to pass credentials to signInWithPassword
• Confusing getSession with logout

5. You want to check if a user is logged in before showing a dashboard. Which code snippet correctly does this using Supabase session management?

hard

A. const session = await supabase.auth.signInWithPassword(); if (session) { showDashboard(); } else { showLogin(); }

B. const session = supabase.auth.signOut(); if (session) { showDashboard(); } else { showLogin(); }

C. const session = supabase.auth.getUser(); if (session) { showDashboard(); } else { showLogin(); }

D. const { data } = await supabase.auth.getSession(); if (data.session) { showDashboard(); } else { showLogin(); }

Solution

1. Step 1: Identify correct session check method

   getSession returns current session info to check login status.

2. Step 2: Verify conditional logic

   If data.session exists, user is logged in; else show login screen.

3. Step 3: Eliminate incorrect options

   signInWithPassword logs users in, signOut logs users out, getUser requires await and checking data.user (e.g. const { data } = await supabase.auth.getUser(); if (data.user)) but const session = supabase.auth.getUser(); if (session) { showDashboard(); } else { showLogin(); } lacks both.

4. Final Answer:

   const { data } = await supabase.auth.getSession(); if (data.session) { showDashboard(); } else { showLogin(); } -> Option D

5. Quick Check:

   Check session with getSession before showing dashboard [OK]

Hint: Use getSession and check data.session to confirm login [OK]

Common Mistakes:

• Using signOut or signInWithPassword to check session
• Using getUser without await and proper data.user check
• Not checking if session is null