Supabase Authentication: Phone Sign-In Guide
Hey guys! Ever wanted to add phone number authentication to your Supabase project? You're in the right place! Phone authentication is a super important feature for many apps these days, adding an extra layer of security and making it easier for users to sign up. Supabase, being the awesome open-source Firebase alternative that it is, makes this process relatively straightforward. In this guide, we'll break down how to set up phone authentication in your Supabase project, step by step. We'll cover everything from enabling the feature in your Supabase dashboard to implementing the necessary client-side code. So, grab your coding hats, and let's dive in!
Setting Up Supabase for Phone Authentication
Okay, first things first, let's get Supabase ready to handle phone authentication. This involves a few configurations in your Supabase project dashboard. Don't worry; it's not as scary as it sounds!
Enable Phone Authentication in Supabase
To enable phone authentication in Supabase, head over to your Supabase project dashboard. Find the Authentication section in the sidebar – usually marked with a key or shield icon. Inside the Authentication settings, look for the Providers tab. You should see a list of different authentication methods like Email/Password, Google, and, of course, Phone. Toggle the switch next to Phone to enable it. Supabase might ask you to configure some additional settings, such as SMS provider details, which we'll cover in the next section.
Configure Your SMS Provider
Alright, listen up! To actually send SMS verification codes, Supabase needs to know which SMS provider to use. Think of SMS providers like Twilio, Vonage (formerly Nexmo), or AWS SNS. Supabase supports several SMS providers, so pick one that suits your needs and budget. Once you've chosen your provider, you'll need to create an account and get your API keys (usually an Account SID and Auth Token for Twilio, or an API Key and Secret for Vonage). Go back to your Supabase project dashboard, and in the Phone Authentication settings, you should find fields to enter these API keys. Make sure you enter them correctly, or else Supabase won't be able to send those sweet, sweet verification codes.
Setting Up the Phone Authentication Template
Phone authentication template is essential for guiding the user in the sign-up process. Often, the sign-up page can become confusing and convoluted when it contains a lot of elements. To solve this problem, you can create a template that breaks up the process into smaller parts. For example, you can separate the page into sections asking for the country code, the phone number, and then the verification code after submission. This breaks up the whole sign-up process and guides the user through it.
Client-Side Implementation: Signing Up and Signing In
Now that Supabase is all set up, let's get our hands dirty with some code! We'll need to implement the sign-up and sign-in flows in our client-side application. This usually involves a bit of JavaScript (or your framework of choice, like React, Vue, or Svelte) to interact with the Supabase API.
Sign-Up with Phone Number
The first step is to allow users to sign up with their phone numbers. This involves collecting the user's phone number and sending a request to Supabase to initiate the sign-up process. Supabase will then send an SMS verification code to the provided phone number. You'll typically have an HTML form with an input field for the phone number and a button to trigger the sign-up. When the user submits the form, you'll use the Supabase client library to call the signUp method with the phone number.
Here's some example JavaScript code using the Supabase client library:
import { createClient } from '@supabase/supabase-js';
const supabaseUrl = 'YOUR_SUPABASE_URL';
const supabaseKey = 'YOUR_SUPABASE_ANON_KEY';
const supabase = createClient(supabaseUrl, supabaseKey);
async function signUpWithPhone(phoneNumber) {
const { data, error } = await supabase.auth.signUp({ phone: phoneNumber });
if (error) {
console.error('Error signing up with phone:', error);
alert('Failed to sign up. Please try again.');
} else {
console.log('Sign-up successful. Verification code sent.');
// Redirect user to verification code input page
}
}
Don't forget to replace YOUR_SUPABASE_URL and YOUR_SUPABASE_ANON_KEY with your actual Supabase project credentials. Also, after a successful sign-up, redirect the user to a page where they can enter the verification code.
Verifying the Code
After the user submits their phone number, Supabase sends them a verification code via SMS. Your app needs a way for the user to enter this code and verify their account. Create another input field for the verification code and a button to submit it. When the user submits the code, you'll use the verifyOtp method in the Supabase client library to verify the code. Here’s some sample JavaScript code for verifying the code:
async function verifyCode(phoneNumber, code) {
const { data, error } = await supabase.auth.verifyOtp({
phone: phoneNumber,
token: code, // Ensure the parameter name is 'token'
type: 'sms',
});
if (error) {
console.error('Error verifying code:', error);
alert('Invalid verification code. Please try again.');
} else {
console.log('Verification successful:', data);
alert('Verification successful!');
// Redirect user to the main app page
}
}
This function sends the phone number and the verification code (code) to Supabase. If the code is correct, Supabase confirms the verification, and you can then redirect the user to the main part of your application. Make sure to handle errors gracefully and let the user know if something goes wrong. It's also good practice to add some loading indicators while waiting for the Supabase API to respond, so the user knows that something is happening.
Sign-In with Phone Number
Once a user has signed up and verified their phone number, they can use it to sign in to your app. The sign-in process is very similar to the sign-up process. Collect the user's phone number, send a request to Supabase to send a verification code, and then verify the code. The main difference is that you'll use the signInWithOtp method instead of the signUp method. Here's some example code:
async function signInWithPhone(phoneNumber) {
const { data, error } = await supabase.auth.signInWithOtp({ phone: phoneNumber });
if (error) {
console.error('Error signing in with phone:', error);
alert('Failed to sign in. Please try again.');
} else {
console.log('Sign-in initiated. Verification code sent.');
// Redirect user to verification code input page
}
}
And here’s the code for verifying the sign-in code, which is identical to the verification code process in the sign-up flow:
async function verifyCode(phoneNumber, code) {
const { data, error } = await supabase.auth.verifyOtp({
phone: phoneNumber,
token: code, // Ensure the parameter name is 'token'
type: 'sms',
});
if (error) {
console.error('Error verifying code:', error);
alert('Invalid verification code. Please try again.');
} else {
console.log('Verification successful:', data);
alert('Verification successful!');
// Redirect user to the main app page
}
}
Handling Edge Cases and Security Considerations
Okay, listen up! While implementing phone authentication, it's super important to think about edge cases and security. You want to make sure your app is secure and handles unexpected situations gracefully.
Rate Limiting
One of the most important things to consider is rate limiting. You don't want malicious actors to spam your SMS provider by repeatedly requesting verification codes for random phone numbers. This can cost you a lot of money and potentially disrupt your service. Supabase doesn't provide built-in rate limiting for phone authentication, so you'll need to implement it yourself. You can do this by tracking the number of SMS requests from a particular IP address or phone number and blocking requests that exceed a certain threshold within a specific time period. Implementing rate limiting will prevent abuse and keep your SMS costs under control.
Input Validation
Always validate user input! Before sending a phone number to Supabase, make sure it's in the correct format. You can use a regular expression to validate the phone number and ensure that it only contains digits and a plus sign. This prevents users from entering invalid phone numbers that could cause errors or security vulnerabilities. Additionally, sanitize the input to prevent any potential injection attacks.
Securely Storing Phone Numbers
If you need to store phone numbers in your database (which is often necessary for user management), make sure you do it securely. Hash the phone numbers using a strong hashing algorithm like bcrypt or Argon2. Never store phone numbers in plain text! Plain text storage leaves user data vulnerable in the event of a data breach. Hashing adds an extra layer of security, making it much harder for attackers to access the actual phone numbers.
User Experience Considerations
Besides security, think about the user experience. Make the phone authentication process as smooth and intuitive as possible. Provide clear instructions to the user and guide them through each step of the process. Use descriptive error messages to help users understand what went wrong and how to fix it. For example, if the user enters an invalid verification code, tell them exactly that, instead of just saying "Error." A well-designed user experience can significantly improve user satisfaction and reduce frustration.
Conclusion
Alright, you've made it to the end! Implementing phone authentication with Supabase involves a few steps, but it's definitely achievable with a bit of effort. You need to set up Supabase, configure your SMS provider, implement the client-side code for signing up and signing in, and handle edge cases and security considerations. Phone authentication adds an extra layer of security and makes it easier for users to sign up for your app. So, go ahead and give it a try! If you run into any problems, don't hesitate to consult the Supabase documentation or ask for help in the Supabase community. Good luck, and happy coding!
