aggregate-multiple-requests.js

// Make multiple requests, aggregate the responses
// and send them back as a single response.
export default {
	/**
	 * @returns {Promise<Response>}
	 */
	async fetch() {
		const init = {
			method: 'GET',
			headers: {
				'Authorization': 'XXXXXX',
				'Content-Type': 'text/plain',
			},
		};

		const [btcResp, ethResp, ltcResp] = await Promise.all([
			fetch('https://api.coinbase.com/v2/prices/BTC-USD/spot', init),
			fetch('https://api.coinbase.com/v2/prices/ETH-USD/spot', init),
			fetch('https://api.coinbase.com/v2/prices/LTC-USD/spot', init),
		]);

		const [btc, eth, ltc] = await Promise.all([btcResp.json(), ethResp.json(), ltcResp.json()]);

		const combined = {
			btc: btc['data'].amount,
			ltc: ltc['data'].amount,
			eth: eth['data'].amount,
		};

		return new Response(JSON.stringify(combined), {
			status: 200,
			headers: {
				'Content-Type': 'application/json',
			},
		});
	},
};