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

Hey there, fellow JavaScript enthusiasts! Ready to dive into the world of FareHarbor integrations? Today, we're going to tackle one of the most crucial aspects of building a public integration: the authorization flow. Buckle up, because we're about to make your integration secure and user-friendly in no time!

Introduction

FareHarbor's API is a powerful tool for integrating booking functionality into your applications. But before we can start making those sweet, sweet API calls, we need to set up a robust authorization flow. This isn't just a box to tick – it's the foundation of a secure and reliable integration. Trust me, your users (and your future self) will thank you for getting this right.

Prerequisites

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

• FareHarbor API credentials (if you don't have these yet, hop over to their developer portal and get set up)
• A Node.js environment with Express.js ready to roll

Got all that? Great! Let's get our hands dirty.

OAuth 2.0 Flow Overview

We'll be implementing the Authorization Code Grant flow – it's the gold standard for user-facing integrations. Here's what you need to know:

• Client ID: Your application's identifier
• Client Secret: Keep this safe! It's the secret sauce of your auth flow
• Redirect URI: Where FareHarbor will send your users after they authorize your app

Implementing the Authorization Flow

Initiating the Auth Request

First things first, let's get that authorization URL set up:

const authUrl = `https://fareharbor.com/oauth/authorize/?client_id=${clientId}&redirect_uri=${redirectUri}&response_type=code`;

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

When a user hits this endpoint, they'll be whisked away to FareHarbor's authorization page. Magic!

Handling the Callback

Now, let's set up our redirect endpoint to catch that authorization code:

app.get('/callback', async (req, res) => {
  const { code } = req.query;
  // We'll use this code in the next step
});

Exchanging the Code for Access Token

Time to trade in that code for an access token:

const tokenResponse = await axios.post('https://fareharbor.com/oauth/token/', {
  grant_type: 'authorization_code',
  code,
  client_id: clientId,
  client_secret: clientSecret,
  redirect_uri: redirectUri
});

const { access_token, refresh_token } = tokenResponse.data;
// Store these securely - we'll need them later!

Refreshing the Access Token

Access tokens don't last forever, so let's implement a refresh mechanism:

async function refreshAccessToken(refreshToken) {
  const response = await axios.post('https://fareharbor.com/oauth/token/', {
    grant_type: 'refresh_token',
    refresh_token: refreshToken,
    client_id: clientId,
    client_secret: clientSecret
  });

  return response.data.access_token;
}

Making Authenticated Requests

Now for the fun part – using that access token:

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

Security Considerations

Listen up, because this part's important:

• Never, ever expose your client secret on the client-side
• Always use HTTPS in production
• Consider implementing PKCE for an extra layer of security

Testing the Auth Flow

Before you ship it, test it! Here's a quick checklist:

1. Start the auth flow and make sure you're redirected to FareHarbor
2. Authorize the app and ensure you're redirected back with a code
3. Check that you can exchange the code for tokens
4. Make an API call and verify you get a valid response
5. Let your access token expire and confirm the refresh flow works

Conclusion

And there you have it! You've just built a rock-solid authorization flow for your FareHarbor integration. With this foundation, you're all set to start building out the rest of your integration. Remember, a secure auth flow is the backbone of any good API integration, so pat yourself on the back – you've done the hard part!

Additional Resources

Want to dive deeper? Check out:

• FareHarbor API Documentation
• OAuth 2.0 Best Practices

Now go forth and integrate with confidence! Happy coding!