Bolt.new AI and Fitbit API integration: Step-by-Step Guide 2025

 

Prerequisites

 

• Setup a Fitbit Developer account at https://dev.fitbit.com and create a new application to obtain your clientid and clientsecret.
• Note your app’s callback URL; this will be used as the redirect URI (e.g. https://your-app.com/fitbit/callback).
• Make sure you have your Bolt.new AI project open.

 

Adding Necessary Dependencies

 

• Since Bolt.new AI doesn’t have a terminal, add a package.json file in the root of your project if it doesn’t exist yet.
• Add the dependency for axios by pasting the following JSON code into the file. This ensures that the required modules are installed when the project loads.

{
  "name": "bolt-fitbit-integration",
  "version": "1.0.0",
  "dependencies": {
    "axios": "^0.27.2"
  }
}

 

Creating the Fitbit API Integration File

 

• Create a new file named fitbit.ts in your project’s source directory.
• This file will contain functions to generate the Fitbit authorization URL and to exchange the authorization code for an access token.
• Paste the code snippet below into fitbit.ts. Replace environment variables as needed.

import axios from 'axios';

const CLIENTID = process.env.FITBITCLIENT_ID as string;
const CLIENTSECRET = process.env.FITBITCLIENT_SECRET as string;
const REDIRECTURI = process.env.FITBITREDIRECT_URI as string;

export function getAuthUrl(): string {
  const scopes = 'activity profile';
  const url = https://www.fitbit.com/oauth2/authorize?response_type=code&client_id=${CLIENT_ID}&redirect_uri=${encodeURIComponent(REDIRECT_URI)}&scope=${encodeURIComponent(scopes)};
  return url;
}

export async function exchangeCodeForToken(code: string): Promise {
  const tokenUrl = 'https://api.fitbit.com/oauth2/token';
  const authHeader = Buffer.from(${CLIENT_ID}:${CLIENT_SECRET}).toString('base64');

  const params = new URLSearchParams();
  params.append('clientid', CLIENTID);
  params.append('granttype', 'authorizationcode');
  params.append('redirecturi', REDIRECTURI);
  params.append('code', code);

  try {
    const response = await axios.post(tokenUrl, params, {
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Authorization': Basic ${authHeader}
      }
    });
    return response.data;
  } catch (error) {
    console.error('Error exchanging code for token:', error);
    throw error;
  }
}

 

Creating Route Handlers for Authentication

 

• Create a new file named routes.ts in your project’s source directory to handle HTTP routes for Fitbit OAuth.
• Insert the following code which uses the functions from fitbit.ts:

import express from 'express';
import { getAuthUrl, exchangeCodeForToken } from './fitbit';

const router = express.Router();

// Route to redirect users to Fitbit for authorization
router.get('/fitbit/auth', (req, res) => {
  const authUrl = getAuthUrl();
  res.redirect(authUrl);
});

// Callback route to handle Fitbit response
router.get('/fitbit/callback', async (req, res) => {
  const code = req.query.code as string;
  if (!code) {
    return res.status(400).send('Authorization code not provided.');
  }
  try {
    const tokenData = await exchangeCodeForToken(code);
    // Process the tokenData (e.g. save tokens for future API calls)
    res.json(tokenData);
  } catch (error) {
    res.status(500).send('Error exchanging code for token.');
  }
});

export default router;

 

Integrating Routes with Your Main Application

 

• Open your main application file (commonly index.ts or app.ts) in your Bolt.new AI project.
• Import the Express framework and the routes from routes.ts.
• Add the routes to your app and make sure your server listens on the correct port. Insert the following snippet into your main file:

import express from 'express';
import fitbitRoutes from './routes';

const app = express();

// Middleware for parsing JSON if needed
app.use(express.json());

// Use the Fitbit API routes
app.use(fitbitRoutes);

// Default route to test the server
app.get('/', (req, res) => {
  res.send('Bolt.new AI Fitbit integration is running.');
});

// Start the server on the port provided by Bolt.new or a default port
const PORT = process.env.PORT || 8080;
app.listen(PORT, () => {
  console.log(Server is listening on port ${PORT});
});

 

Configuring Environment Variables

 

• Because Bolt.new AI does not expose a terminal for setting environment variables, use its built-in secrets feature.
• Add the following keys and their corresponding values (from your Fitbit Developer app) using your project’s environment variable configuration:
• FITBITCLIENTID – your Fitbit client ID
• FITBITCLIENTSECRET – your Fitbit client secret
• FITBITREDIRECTURI – the callback URL you registered with Fitbit

 

Testing Your Integration

 

• Deploy your project on Bolt.new AI by clicking the Run button.
• Visit the default route (e.g. /) to ensure your server is up.
• Navigate to /fitbit/auth to be redirected to Fitbit’s authorization page. After authorizing, Fitbit will redirect you to your callback URL where the access token details are returned as JSON.

 

Final Notes

 

• Make sure to handle and store the token data securely if you plan to make additional API calls on behalf of the user.
• This guide assumes the Bolt.new AI project supports Express-based routing. Adjust accordingly if your project structure is different.