Aggregate requests

Send two GET request to two urls and aggregates the responses into one response.

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This creates a repository in your GitHub account and deploys the application to Cloudflare Workers.

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);
    },
};

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;

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;

from workers import Response, fetch, WorkerEntrypoint
import asyncio
import json

class Default(WorkerEntrypoint):
    async def fetch(self, 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)

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description: Example of how to add, change, or delete headers sent in a request or returned in a response. title: Alter headers image: https://developers.cloudflare.com/workers/examples/alter-headers/og.png?v=d39783579ea7a60c

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