Spotify

import { getNowPlaying } from '../../lib/spotify';

export default async (_, res) => {
  const response = await getNowPlaying();

  if (response.status === 204 || response.status > 400) {
    return res.status(200).json({ isPlaying: false });
  }

  const song = await response.json();
  const isPlaying = song.is_playing;
  const title = song.item.name;
  const artist = song.item.artists.map((_artist) => _artist.name).join(', ');
  const album = song.item.album.name;
  const albumImageUrl = song.item.album.images[0].url;
  const songUrl = song.item.external_urls.spotify;

  return res.status(200).json({
    album,
    albumImageUrl,
    artist,
    isPlaying,
    songUrl,
    title
  });
};

// lib/spotify.js

import fetch from 'isomorphic-unfetch';
import querystring from 'querystring';

const client_id = process.env.SPOTIFY_CLIENT_ID;
const client_secret = process.env.SPOTIFY_CLIENT_SECRET;
const refresh_token = process.env.SPOTIFY_REFRESH_TOKEN;

const basic = Buffer.from(`${client_id}:${client_secret}`).toString('base64');
const NOW_PLAYING_ENDPOINT = `https://api.spotify.com/v1/me/player/currently-playing`;
const TOKEN_ENDPOINT = `https://accounts.spotify.com/api/token`;

const getAccessToken = async () => {
  const response = await fetch(TOKEN_ENDPOINT, {
    method: 'POST',
    headers: {
      Authorization: `Basic ${basic}`,
      'Content-Type': 'application/x-www-form-urlencoded'
    },
    body: querystring.stringify({
      grant_type: 'refresh_token',
      refresh_token
    })
  });

  return response.json();
};

export const getNowPlaying = async () => {
  const { access_token } = await getAccessToken();

  return fetch(NOW_PLAYING_ENDPOINT, {
    headers: {
      Authorization: `Bearer ${access_token}`
    }
  });
};

Usage

First, we need to create a Spotify application to give us credentials to authenticate with the API.

• Go to your Spotify Developer Dashboard and log in.
• Click Create an App.
• Fill out the name and description and click create.
• Click Show Client Secret.
• Save your Client ID and Secret. You'll need these soon.
• Click Edit Settings.
• Add http://localhost:3000 as a redirect URI.

All done! You now have a properly configured Spotify application and the correct credentials to make requests.

There are a variety of ways to authenticate with the Spotify API, depending on your application. Since we only need permission granted once, we'll use the Authorization Code Flow.

First, we'll have our application request authorization by logging in with whatever scopes we need. Here's an example of what the URL might look like. Swap out the client_id and scopes for your own.

https://accounts.spotify.com/authorize?client_id=8e94bde7dd
b84a1f7a0e51bf3bc95be8&response_type=code&redirect_uri=http
%3A%2F%2Flocalhost:3000&scope=user-read-currently-playing%20
user-top-read

After authorizing, you'll be redirected back to your redirect_uri. In the URL, there's a code query parameter. Save this value.

http://localhost:3000/callback?code=NApCCg..BkWtQ

Next, we'll need to retrieve the refresh token. You'll need to generate a Base 64 encoded string containing the client ID and secret from earlier. You can use this tool to encode it online. The format should be client_id:client_secret.

curl -H "Authorization: Basic <base64 encoded client_id:client_secret>"
-d grant_type=authorization_code -d code=<code> -d redirect_uri=http%3A
%2F%2Flocalhost:3000 https://accounts.spotify.com/api/token

This will return a JSON response containing a refresh_token. This token is valid indefinitely unless you revoke access, so we'll want to save this in an 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.