Forex Dashboard v8.0

2026-08-16 05:58:05 +00:00 · 2026-05-27 13:18:45 +02:00
commit 236afa3087
31 changed files with 9292 additions and 0 deletions
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+import { NextResponse } from "next/server";
+
+// AV primary (real-time) → Frankfurter fallback (ECB daily)
+// AV free plan: 25 req/day, 5 req/min
+// With revalidate:86400, server fetches each URL at most once per day → 7 calls/day total
+const CURRENCIES = ["EUR", "GBP", "JPY", "CHF", "CAD", "AUD", "NZD"];
+const AV_BASE    = "https://www.alphavantage.co/query";
+
+export async function GET() {
+  const avKey = process.env.ALPHA_VANTAGE_KEY;
+  if (avKey) {
+    const result = await fetchAV(avKey);
+    if (result) return NextResponse.json(result);
+  }
+  return fetchFrankfurter();
+}
+
+async function fetchAV(apiKey: string) {
+  // Sequential (not parallel) to respect AV's 5 req/min limit
+  const rates: Record<string, number> = {};
+  for (const ccy of CURRENCIES) {
+    try {
+      const url = `${AV_BASE}?function=CURRENCY_EXCHANGE_RATE&from_currency=USD&to_currency=${ccy}&apikey=${apiKey}`;
+      const res  = await fetch(url, { next: { revalidate: 86400 } }); // 24h server cache
+      if (!res.ok) continue;
+      const json = await res.json();
+      const rate = json?.["Realtime Currency Exchange Rate"]?.["5. Exchange Rate"];
+      if (rate) rates[ccy] = parseFloat(rate);
+    } catch { /* skip on error */ }
+  }
+  if (Object.keys(rates).length < 4) return null; // too many failures → fall back
+  // Approximate DXY from fetched pairs (no extra AV call needed)
+  // DXY = 50.14 × EUR^0.576 × (1/JPY)^0.136 × GBP^0.119 × (1/CAD)^0.091 × (1/CHF)^0.036
+  const e = rates.EUR, g = rates.GBP, j = rates.JPY, c = rates.CAD, ch = rates.CHF;
+  const dxy = (e && g && j && c && ch)
+    ? parseFloat((50.14348112 * Math.pow(e,0.576) * Math.pow(1/j,0.136) * Math.pow(g,0.119) * Math.pow(1/c,0.091) * Math.pow(1/ch,0.036)).toFixed(3))
+    : null;
+  return { rates, dxy, base: "USD", source: "alphavantage", timestamp: Date.now() };
+}
+
+async function fetchFrankfurter() {
+  try {
+    const res = await fetch("https://api.frankfurter.app/latest?from=USD", { next: { revalidate: 86400 } });
+    if (!res.ok) throw new Error(`Frankfurter ${res.status}`);
+    const data = await res.json();
+    return NextResponse.json({ rates: data.rates, dxy: null, base: "USD", source: "frankfurter", date: data.date });
+  } catch (err) {
+    return NextResponse.json({ error: String(err) }, { status: 502 });
+  }
+}