Start with a Blank Project:
Vercel lets you create a project without any pre-made template files. This is often easiest if you only need a single serverless function (like our proxy).
Summary
Vercel Serverless Functions: They’re free, don’t sleep, and are very simple to deploy.
Minimal Code: You only need one file (api/fred.js) that fetches the data and adds the CORS header.
No Extra Maintenance: Once deployed, you get a stable URL that you can use in your front-end.
This is one of the simplest long‑term solutions to fix the CORS issue with the FRED API while keeping your costs at zero (within Vercel’s free tier). Let me know if you need any more details or help with any of these steps!
I'd be happy to help you create a simple serverless function on Vercel to proxy requests to the FRED API and handle CORS. Let's go through the process step by step.
Let's start by creating a new Vercel project with a single serverless function:
- First, create a new directory for your project and navigate into it:
mkdir fred-api-proxy
cd fred-api-proxy- Initialize a new Node.js project:
npm init -y- Create an
apidirectory and a file namedfred.jsinside it:
mkdir api
touch api/fred.js- Now, let's implement the proxy function in
api/fred.js:
This serverless function does the following:
- Sets CORS headers to allow requests from any origin.
- Handles preflight OPTIONS requests.
- Retrieves the FRED API key from environment variables.
- Extracts the
series_idfrom the query parameters. - Constructs the FRED API URL.
- Fetches data from the FRED API using the
httpsmodule. - Returns the FRED API response to the client.
- Create a
vercel.jsonfile in the root of your project to configure the Vercel deployment:
This configuration ensures that requests to /api/fred are routed to your serverless function.
- To deploy this project to Vercel, you'll need to:
a. Install the Vercel CLI:
npm install -g vercelb. Log in to your Vercel account:vercel loginc. Deploy the project:vercel - During the deployment process, you'll be prompted to set up environment variables. Make sure to add your FRED API key as
FRED_API_KEY.
Once deployed, Vercel will provide you with a URL for your serverless function. You can now use this URL in your front-end application to make requests to the FRED API without CORS issues.
For example, if you want to fetch data for the GDP series (series_id: GDPC1), you would make a request to:
https://your-vercel-url.vercel.app/api/fred?series_id=GDPC1This solution provides a simple, maintenance-free way to proxy FRED API requests and handle CORS issues. It's free to use within Vercel's generous free tier limits, and the serverless function will always be available without any cold start issues 1.
Remember to keep your FRED API key secure by using Vercel's environment variables feature and never exposing it in your client-side code 1.
Please make sure to add the following environment variable to your project:
Thank you for confirming that you've added the FRED_API_KEY environment variable to your Vercel project. That's an important step in securing your API key. Now, let's make some adjustments to your api/fred.js file to use this environment variable and make the function more flexible.
Let's update your api/fred.js file:
These changes accomplish the following:
- We're now using
process.env.FRED_API_KEYto access the API key from the environment variables 1. - The
series_idis now extracted from the query parameters, making the function more flexible. - We've added error handling for when
series_idis not provided in the request. - CORS headers are set for all types of requests, and we're handling OPTIONS requests for CORS preflight 2.
- Error messages are more generic in the response to avoid exposing sensitive information.
Your vercel.json file looks good as it is, so we don't need to make any changes there.
Now, when you deploy this updated function to Vercel, it will use the FRED_API_KEY from your environment variables and allow you to query different series by passing the series_id as a query parameter.
To use this function, you would make a request like this:
https://your-vercel-url.vercel.app/api/fred?series_id=GDPC1This setup provides a secure and flexible way to proxy requests to the FRED API. It uses environment variables for the API key, handles CORS issues, and allows you to query any series by passing the series_id as a parameter 12.
Remember, you don't need to include a package.json file or install node-fetch manually. Vercel will automatically install the necessary dependencies based on the require statements in your code 1.
Is there anything else you'd like to modify or any questions about how to use this serverless function?