backend/router_crypto.py

from fastapi import APIRouter
import os, requests

router = APIRouter()

API_KEY = os.getenv("APILAYER_KEY")

@router.get("/price")
def get_price(base: str = "BTC", quote: str = "USD"):
    url = f"https://api.apilayer.com/exchangerates_data/latest?base={base}&symbols={quote}"
    headers = {"apikey": API_KEY}
    r = requests.get(url, headers=headers)
    data = r.json()
    if "error" in data or not data.get("success"):
        return {"error": data.get("error", "API call failed")}
    return {"base": base, "quote": quote, "rate": data["rates"].get(quote)}