Dropzon Public API

const express = require('express');
const crypto = require('crypto');
const app = express();

const CLIENT_ID = 'dzo_your_client_id';
const CLIENT_SECRET = 'dzs_your_client_secret';
const REDIRECT_URI = 'https://yourapp.com/callback';
const OAUTH_AUTHORIZE = 'https://dropzon.app/oauth';  // consent screen (frontend)
const OAUTH_API = 'https://api.dropzon.app/api/oauth';              // token + userinfo (API)

// Step 1: Redirect to Dropzon
app.get('/login', (req, res) => {
  const state = crypto.randomBytes(16).toString('hex');
  req.session.oauthState = state;

  const params = new URLSearchParams({
    client_id: CLIENT_ID,
    redirect_uri: REDIRECT_URI,
    response_type: 'code',
    scope: 'profile email',
    state,
  });

  res.redirect(OAUTH_AUTHORIZE + '/authorize?' + params);
});

// Step 3-4: Handle callback and exchange code
app.get('/callback', async (req, res) => {
  const { code, state, error } = req.query;

  if (error) return res.send('Authorization denied');
  if (state !== req.session.oauthState) return res.status(403).send('Invalid state');

  // Exchange code for tokens
  const tokenRes = await fetch(OAUTH_API + '/token', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      grant_type: 'authorization_code',
      code,
      redirect_uri: REDIRECT_URI,
      client_id: CLIENT_ID,
      client_secret: CLIENT_SECRET,
    }),
  });
  const { data: tokens } = await tokenRes.json();

  // Step 5: Fetch user info
  const userRes = await fetch(OAUTH_API + '/userinfo', {
    headers: { Authorization: 'Bearer ' + tokens.access_token },
  });
  const { data: user } = await userRes.json();

  // user = { sub, name, email, ... }
  req.session.user = user;
  res.redirect('/dashboard');
});

<a href="https://dropzon.app/oauth/authorize?client_id=YOUR_CLIENT_ID&redirect_uri=YOUR_REDIRECT_URI&response_type=code&scope=profile email&state=RANDOM_STATE"
   style="display:inline-flex;align-items:center;gap:10px;height:44px;padding:0 20px;background:#0d84d4;color:#fff;border:none;border-radius:12px;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;font-size:14px;font-weight:600;text-decoration:none;cursor:pointer;transition:opacity 0.15s;"
   onmouseover="this.style.opacity='0.9'" onmouseout="this.style.opacity='1'">
  <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none"><path d="M12 2C8.13 2 5 5.13 5 9c0 5.25 7 13 7 13s7-7.75 7-13c0-3.87-3.13-7-7-7z" fill="#ffffff"/><circle cx="12" cy="9" r="2.5" fill="white"/></svg>
  Sign in with Dropzon
</a>