Fix EIA API routing with Vercel catch-all route

api/eia/[[...path]].js

@@ -0,0 +1,111 @@
+// EIA (Energy Information Administration) API proxy
+// Keeps API key server-side
+export const config = { runtime: 'edge' };
+
+export default async function handler(req) {
+  const url = new URL(req.url);
+  const path = url.pathname.replace('/api/eia', '');
+
+  const apiKey = process.env.EIA_API_KEY;
+
+  if (!apiKey) {
+    return Response.json({
+      error: 'EIA API not configured',
+      configured: false,
+      message: 'Get a free API key at https://www.eia.gov/opendata/',
+    }, {
+      status: 503,
+      headers: { 'Access-Control-Allow-Origin': '*' },
+    });
+  }
+
+  // Handle CORS preflight
+  if (req.method === 'OPTIONS') {
+    return new Response(null, {
+      status: 204,
+      headers: {
+        'Access-Control-Allow-Origin': '*',
+        'Access-Control-Allow-Methods': 'GET, OPTIONS',
+        'Access-Control-Allow-Headers': 'Content-Type',
+      },
+    });
+  }
+
+  // Health check
+  if (path === '/health' || path === '') {
+    return Response.json({ configured: true }, {
+      headers: { 'Access-Control-Allow-Origin': '*' },
+    });
+  }
+
+  // Petroleum data endpoint
+  if (path === '/petroleum') {
+    try {
+      const series = {
+        wti: 'PET.RWTC.W',
+        brent: 'PET.RBRTE.W',
+        production: 'PET.WCRFPUS2.W',
+        inventory: 'PET.WCESTUS1.W',
+      };
+
+      const results = {};
+
+      // Fetch all series in parallel
+      const fetchPromises = Object.entries(series).map(async ([key, seriesId]) => {
+        try {
+          const response = await fetch(
+            `https://api.eia.gov/v2/seriesid/${seriesId}?api_key=${apiKey}&num=2`,
+            { headers: { 'Accept': 'application/json' } }
+          );
+
+          if (!response.ok) return null;
+
+          const data = await response.json();
+          const values = data?.response?.data || [];
+
+          if (values.length >= 1) {
+            return {
+              key,
+              data: {
+                current: values[0]?.value,
+                previous: values[1]?.value || values[0]?.value,
+                date: values[0]?.period,
+                unit: values[0]?.unit,
+              }
+            };
+          }
+        } catch (e) {
+          console.error(`[EIA] Failed to fetch ${key}:`, e.message);
+        }
+        return null;
+      });
+
+      const fetchResults = await Promise.all(fetchPromises);
+
+      for (const result of fetchResults) {
+        if (result) {
+          results[result.key] = result.data;
+        }
+      }
+
+      return Response.json(results, {
+        headers: {
+          'Access-Control-Allow-Origin': '*',
+          'Cache-Control': 'public, max-age=1800', // 30 min cache
+        },
+      });
+    } catch (error) {
+      return Response.json({
+        error: `EIA fetch failed: ${error.message}`,
+      }, {
+        status: 500,
+        headers: { 'Access-Control-Allow-Origin': '*' },
+      });
+    }
+  }
+
+  return Response.json({ error: 'Not found' }, {
+    status: 404,
+    headers: { 'Access-Control-Allow-Origin': '*' },
+  });
+}