Magic link integration using Lemón’s transactional email API

1. Generate the Magic Link

Use an authentication provider (e.g., Firebase, Auth0, or a custom token generator) to create a time-sensitive link. For simplicity, let’s assume you're using a custom token generator.

Example (Node.js):

const crypto = require("crypto");

// Generate a secure token
const generateMagicLink = (email) => {
    const token = crypto.randomBytes(32).toString("hex");
    const redirectUri = encodeURIComponent(`https://yourapp.com/verify?token=${token}`);
    return { magicLink: redirectUri, token };
};

2. Send the Magic Link via Lemón

Using Lemón’s transactional email API, send the generated link.

Node.js Example:

const axios = require("axios");

// Magic Link Generation
const { magicLink, token } = generateMagicLink("recipient@domain.com");

// Lemón Email API Call
const sendMagicLink = async () => {
    const payload = {
        fromname: "YourApp",
        fromemail: "no-reply@yourapp.com",
        to: "recipient@domain.com",
        subject: "Your Magic Login Link",
        body: `
            <html>
            <body>
                <p>Hello,</p>
                <p>Click the link below to log in:</p>
                <a href="${magicLink}">Log in</a>
                <p>This link will expire in 10 minutes.</p>
            </body>
            </html>
        `
    };

    try {
        const response = await axios.post(
            "https://app.xn--lemn-sqa.com/api/transactional/send",
            payload,
            {
                headers: {
                    "Content-Type": "application/json",
                    "X-Auth-APIKey": "YOUR_API_KEY"
                }
            }
        );
        console.log("Email sent successfully:", response.data);
    } catch (error) {
        console.error("Error sending email:", error.response?.data || error.message);
    }
};

sendMagicLink();

3. Handle the Magic Link on the Backend

When the user clicks the link, validate the token.

Backend Validation Example:

const express = require("express");
const app = express();

const tokenStore = new Map(); // Replace with a database in production

// Simulate storing tokens
tokenStore.set("some-token", { email: "recipient@domain.com", expiresAt: Date.now() + 600000 });

app.get("/verify", (req, res) => {
    const token = req.query.token;

    if (!tokenStore.has(token)) {
        return res.status(400).send("Invalid or expired link.");
    }

    const { email, expiresAt } = tokenStore.get(token);
    if (Date.now() > expiresAt) {
        return res.status(400).send("Link has expired.");
    }

    // Log in the user or start a session
    res.send(`Welcome back, ${email}!`);
});

app.listen(3000, () => console.log("Server running on port 3000"));

4. Test the Integration

Use your app to send a magic link.
Click the link in the email.
Verify that the link redirects and authenticates the user properly.