import asyncio, httpx
from fastapi import FastAPI

app = FastAPI()

@app.get('/agg')
async def agg():
    async with httpx.AsyncClient() as c:
        a, b = await asyncio.gather(
            c.get('https://x/1'), c.get('https://x/2'))
    return {'a': a.status_code, 'b': b.status_code}