How to build a public Salesmsg integration: Building the Auth Flow

Hey there, fellow JavaScript aficionados! Ready to dive into the world of Salesmsg integration? Today, we're focusing on the crucial part of any integration: the authorization flow. Buckle up, because we're about to make your Salesmsg integration secure and user-friendly.

Prerequisites

Before we jump in, make sure you've got:

• Node.js and npm installed
• Your favorite code editor
• Salesmsg API credentials (if you don't have these, hop over to the Salesmsg developer portal and grab 'em)

Setting up the project

Let's kick things off by setting up our project:

mkdir salesmsg-integration
cd salesmsg-integration
npm init -y
npm install express axios dotenv

Understanding Salesmsg OAuth 2.0 flow

Salesmsg uses OAuth 2.0 for authorization. In a nutshell, it goes like this:

1. We redirect the user to Salesmsg's login page
2. User grants permission
3. Salesmsg sends us an authorization code
4. We exchange that code for an access token
5. We use the access token to make API calls

Simple, right? Let's make it happen!

Implementing the authorization request

First, let's set up our server and create the authorization URL:

require('dotenv').config();
const express = require('express');
const app = express();

const authUrl = `https://api.salesmsg.com/oauth/authorize?client_id=${process.env.CLIENT_ID}&redirect_uri=${encodeURIComponent(process.env.REDIRECT_URI)}&response_type=code`;

app.get('/auth', (req, res) => {
  res.redirect(authUrl);
});

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

Handling the callback

Now, let's handle that callback and grab the authorization code:

app.get('/callback', async (req, res) => {
  const { code } = req.query;
  if (code) {
    // We'll use this code in the next step
    console.log('Authorization code:', code);
    res.send('Authorization successful! You can close this window.');
  } else {
    res.status(400).send('Authorization failed');
  }
});

Exchanging the code for access token

Time to trade that code for an access token:

const axios = require('axios');

async function getAccessToken(code) {
  try {
    const response = await axios.post('https://api.salesmsg.com/oauth/token', {
      grant_type: 'authorization_code',
      client_id: process.env.CLIENT_ID,
      client_secret: process.env.CLIENT_SECRET,
      code,
      redirect_uri: process.env.REDIRECT_URI
    });
    return response.data.access_token;
  } catch (error) {
    console.error('Error getting access token:', error.response.data);
    throw error;
  }
}

Refreshing the access token

Don't forget to implement token refresh:

async function refreshAccessToken(refreshToken) {
  try {
    const response = await axios.post('https://api.salesmsg.com/oauth/token', {
      grant_type: 'refresh_token',
      client_id: process.env.CLIENT_ID,
      client_secret: process.env.CLIENT_SECRET,
      refresh_token: refreshToken
    });
    return response.data.access_token;
  } catch (error) {
    console.error('Error refreshing token:', error.response.data);
    throw error;
  }
}

Securing the token storage

Remember, treat access tokens like passwords. Store them securely, preferably encrypted. For this example, we'll use environment variables, but in a production app, you'd want something more robust.

Making authenticated requests

Now that we have our token, let's use it:

async function makeAuthenticatedRequest(accessToken) {
  try {
    const response = await axios.get('https://api.salesmsg.com/v1/user', {
      headers: { Authorization: `Bearer ${accessToken}` }
    });
    return response.data;
  } catch (error) {
    if (error.response && error.response.status === 401) {
      // Time to refresh that token!
      const newToken = await refreshAccessToken(refreshToken);
      // Retry the request with the new token
    }
    throw error;
  }
}

Error handling and edge cases

Always be prepared for things to go wrong. Implement proper error handling and provide clear error messages to your users. Remember, a good error message can save hours of debugging!

Testing the auth flow

Before you ship it, test it! Try different scenarios:

• Happy path (everything works)
• Invalid credentials
• Expired tokens
• Network errors

Consider setting up automated tests to catch any regressions.

Wrapping up

And there you have it! You've just built a robust authorization flow for your Salesmsg integration. Pretty cool, right? Remember, this is just the beginning. From here, you can start building out the rest of your integration, adding more features and functionality.

Keep coding, keep learning, and most importantly, keep having fun with it! If you run into any snags, the Salesmsg docs and community are great resources. Now go forth and integrate!