Get all sales of a product in dollars.

import fetch from 'isomorphic-unfetch';

export default async (_, res) => {
  const apiKey = process.env.GUMROAD_API_KEY;
  const productId = 'sDpG';
  const response = await fetch(
      headers: {
        Authorization: `Bearer ${apiKey}`,
        'Content-Type': 'application/json'
      method: 'GET'

  const { product } = await response.json();
  const sales = product.sales_usd_cents / 100;

  return res.status(200).json({ sales });



Create Gumroad Account

First, create a Gumroad account. Then, navigate to the Applications tab and create a new app.


Save Application Secret

Make note of your "Application Secret". Since we're communicating server to server, we only need the secret.


Add Environment Variable

To securely access the API, we need to include the secret with each request. We also do not want to commit secrets to git. Thus, we should use an environment variable. Learn how to add environment variables in Vercel.