Sign In with Email/Phone Number

Our JavaScript SDK offers the easiest way to integrate Cotter 's email/phone verification. You can simply embed Cotter's Login Form and it will do the heavy lifting for you.

Concepts: Learn about how Sign in with Email/Phone Number works.

What you're building

Try it out

Quickly try out how it works in our Hello World Example! 🎉

Overview

Verifying email and phone number in your website using our JavaScript SDK consists of the following steps:

Embed Cotter in your website
Receive a Callback with user's data and a token from Cotter
Send the token to your backend server

Steps

Setup Cotter with your API_KEY_ID and some config
Show Cotter form
Send the Payload containing the user's information to your backend server

Step 1: Setup Cotter

Include Javascript SDK

To use our Javascript SDK, include the script below in your HTML page or use the npm package.

<script
    src="https://unpkg.com/[email protected]/dist/cotter.min.js"
    type="text/javascript"
></script>

Make sure you check for the latest version at https://www.npmjs.com/package/cotter

npm install cotter --save

yarn add cotter

Initialize Cotter

Initialize Cotter in your Login page. If using HTML, put this script at the bottom of your <body> . If you're using React, put this in useEffect or componentDidMount . We want this script to run right after the page is loaded.

<script>
  var cotter = new Cotter("<YOUR_API_KEY_ID>"); // 👈 Specify your API KEY ID here

   cotter
    .withFormID("form_default") // Use customization for form "form_default"
    .signInWithLink()  // to send a verification code, use .signInWithOTP()
    .showEmailForm()  // to send via phone number use .showPhoneForm()
    .then(payload => {
      // payload is Cotter's token containing user information
      console.log("Cotter User Information", payload);
      // ==================================
      // TODO: Login to backend
      // ==================================
  })
  .catch(err => console.log(err));
</script>

import Cotter from "cotter"; //  1️⃣  Import Cotter

//...

useEffect(() => {
  var cotter = new Cotter(API_KEY_ID); // 👈 Specify your API KEY ID here
  
  cotter
    .withFormID("form_default") // Use customization for form "form_default"
    .signInWithLink()  // to send a verification code, use .signInWithOTP()
    .showEmailForm()  // to send via phone number use .showPhoneForm()
    .then(payload => {
      // payload is Cotter's token containing user information
      console.log("Cotter User Information", payload);
      // ==================================
      // TODO: Login to backend
      // ==================================
  })
  .catch(err => console.log(err));
}, []);

Adding more fields

You can also add more fields, customize the styles, and intercept the authentication request before it's sent. Check out how to Customize the Form.

Send Code via WhatsApp

Instead of using SMS, you can also send the code via WhatsApp. Go to the Dashboard > Branding and chose "Phone" on top of the preview.

To send code/link via SMS or WhatsApp, you'll need to add some balance to you project in the Dashboard.

Step 2: Show Cotter Form

Add the <div> container with id "cotter-form-container"

<div
  id="cotter-form-container"
  style="width: 300px; height: 300px;"
></div>

{/*  3️⃣  Put a <div> that will contain the form */}
<div id="cotter-form-container" style={{ width: 300, height: 300 }} />

What we have so far

<script
    src="https://unpkg.com/[email protected]/dist/cotter.min.js"
    type="text/javascript"
></script>

<div
  id="cotter-form-container"
  style="width: 300px; height: 300px;"
></div>

<script>
  var cotter = new Cotter("<YOUR_API_KEY_ID>"); // 👈 Specify your API KEY ID here

  cotter
    .withFormID("form_default") // Use customization for form "form_default"
    .signInWithLink()
    .showEmailForm()  // to send via phone number use .showPhoneForm()
    .then(payload => {
      console.log("Cotter User Information", payload);
      // TODO: Login to server
    })
    .catch(err => console.log(err));
</script>

import React, { useEffect } from "react";
import Cotter from "cotter"; //  1️⃣  Import Cotter

function App() {

  //  2️⃣ Initialize and show the form
  useEffect(() => {
    var cotter = new Cotter(API_KEY_ID); // 👈 Specify your API KEY ID here
    
    cotter
      .withFormID("form_default") // Use customization for form "form_default"
      .signInWithLink() 
      .showEmailForm()
      .then(payload => {
        console.log("Cotter User Information", payload);
        // TODO: Login to server
    })
    .catch(err => console.log(err));
  }, []);

  return (
    <div>
      {/*  3️⃣  Put a <div> that will contain the form */}
      <div id="cotter-form-container" style={{ width: 300, height: 300 }} />
    </div>
  );
}

export default App;

Step 3: Sending the Payload to your Backend Server

You can get the authentication response in the then callback function and send it to your server. For example:

var cotter = new Cotter("<YOUR_API_KEY_ID>");

cotter
  .withFormID("form_default") // Use customization for form "form_default"
  .signInWithLink()
  .showEmailForm() 
  .then(payload => {
    console.log("Cotter User Information", payload);
    
    // TODO: Login to Server
    axios
      .post("http://localhost:3005/login", payload)
      .then((resp) => console.log("Response From Server", resp))
      .catch((err) => console.log(err));
  })
  .catch(err => console.log(err));

The payload that you receive from the promise is a JSON Object with the following format:

{
    "email": "[email protected]", // User's email (or phone number)
    "oauth_token": {
        "access_token": "eyJhbGciOiJFUzI1NiIsImt...", // Access Token to validate
        "id_token": "eyJhbGciOiJFUzI1Ni...",
        "refresh_token": "27805:CNf76faa8trMhjXM...",
        "expires_in": 3600,
        "token_type": "Bearer",
        "auth_method": "OTP"
    },
    "user": {
        "ID": "abcdefgh-abcd-abcd-abcd-af6f81fb5432", // [Deprecated] Cotter User ID
        "created_at": "2020-07-21T05:50:14.182738Z",
        "updated_at": "2020-07-21T06:00:47.115096Z",
        "deleted_at": "0001-01-01T00:00:00Z",
        "issuer": "<YOUR_API_KEY_ID>",
        "identifier": "[email protected]"
    }
}

Please use the identifier (email/phone number) as your main way to identify users, user.ID is deprecated.

You should verify the access token to ensure this is valid and it comes from Cotter's server.

Handling the response in your backend

Backend: Handling Response

🎉 You're done!

Securing your Project

Since you'll be using your API Key from a front-end website or mobile app, your API_KEY_ID is exposed to anyone inspecting your code. Here are some ways to prevent abuse:

What's Next

Styling the Form: You can add Styling from the dashboard or add custom CSS
Add Additional Fields: Add fields like Name, Address, etc to the login form
Check the email/phone before logging in: Useful for employees-only portals, RSVP, waitlists, checking if the user is registered, etc.

PreviousWeb NextCustomize the Form

Last updated 3 years ago