Aggregate requests

JavaScript

export default {
  async fetch(request) {
    // someHost is set up to return JSON responses
    const someHost = "https://jsonplaceholder.typicode.com";
    const url1 = someHost + "/todos/1";
    const url2 = someHost + "/todos/2";

    const responses = await Promise.all([fetch(url1), fetch(url2)]);
    const results = await Promise.all(responses.map((r) => r.json()));

    const options = {
      headers: { "content-type": "application/json;charset=UTF-8" },
    };
    return new Response(JSON.stringify(results), options);
  },
};

TypeScript

export default {
  async fetch(request) {
    // someHost is set up to return JSON responses
    const someHost = "https://jsonplaceholder.typicode.com";
    const url1 = someHost + "/todos/1";
    const url2 = someHost + "/todos/2";

    const responses = await Promise.all([fetch(url1), fetch(url2)]);
    const results = await Promise.all(responses.map((r) => r.json()));

    const options = {
      headers: { "content-type": "application/json;charset=UTF-8" },
    };
    return new Response(JSON.stringify(results), options);
  },
} satisfies ExportedHandler;

Hono

import { Hono } from "hono";

const app = new Hono();

app.get("*", async (c) => {
  // someHost is set up to return JSON responses
  const someHost = "https://jsonplaceholder.typicode.com";
  const url1 = someHost + "/todos/1";
  const url2 = someHost + "/todos/2";

  // Fetch both URLs concurrently
  const responses = await Promise.all([fetch(url1), fetch(url2)]);

  // Parse JSON responses concurrently
  const results = await Promise.all(responses.map((r) => r.json()));

  // Return aggregated results
  return c.json(results);
});

export default app;

Python

from workers import Response, fetch
import asyncio
import json

async def on_fetch(request):
    # some_host is set up to return JSON responses
    some_host = "https://jsonplaceholder.typicode.com"
    url1 = some_host + "/todos/1"
    url2 = some_host + "/todos/2"

    responses = await asyncio.gather(fetch(url1), fetch(url2))
    results = await asyncio.gather(*(r.json() for r in responses))

    headers = {"content-type": "application/json;charset=UTF-8"}
    return Response.json(results, headers=headers)