Create token exchange endpoint for Foundation OAuth

cgen-8034b9e955d547db9961099058064abf

api/auth/exchange-token.ts

@@ -0,0 +1,75 @@
+/**
+ * Token Exchange Endpoint
+ * 
+ * Frontend calls this endpoint after receiving the authorization code from Foundation.
+ * It stores the Foundation's access token and returns user information.
+ */
+
+import { VercelRequest, VercelResponse } from "@vercel/node";
+
+const FOUNDATION_URL = process.env.VITE_FOUNDATION_URL || "https://aethex.foundation";
+const API_BASE = process.env.VITE_API_BASE || "https://aethex.dev";
+
+export default async function handler(
+  req: VercelRequest,
+  res: VercelResponse,
+) {
+  if (req.method !== "POST") {
+    return res.status(405).json({ error: "Method not allowed" });
+  }
+
+  const { code } = req.body;
+
+  if (!code) {
+    return res.status(400).json({ error: "Authorization code is required" });
+  }
+
+  try {
+    // Exchange code for token with Foundation
+    const tokenResponse = await fetch(`${FOUNDATION_URL}/api/oauth/token`, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({
+        grant_type: "authorization_code",
+        code,
+        client_id: "aethex-corp",
+        client_secret: process.env.FOUNDATION_OAUTH_CLIENT_SECRET,
+        redirect_uri: `${API_BASE}/api/auth/foundation-callback`,
+      }),
+    });
+
+    if (!tokenResponse.ok) {
+      const errorData = await tokenResponse.json().catch(() => ({}));
+      console.error("[Exchange Token] Token exchange failed:", errorData);
+      return res.status(400).json({
+        error: "Failed to exchange code for token",
+        details: errorData,
+      });
+    }
+
+    const tokenData = await tokenResponse.json();
+
+    if (!tokenData.access_token) {
+      return res.status(400).json({ error: "No access token in response" });
+    }
+
+    // Set cookie with access token
+    res.setHeader("Set-Cookie", [
+      `foundation_access_token=${tokenData.access_token}; Path=/; HttpOnly; Secure; SameSite=Strict`,
+      `auth_user_id=${tokenData.user?.id || ""}; Path=/; Secure; SameSite=Strict`,
+    ]);
+
+    return res.status(200).json({
+      accessToken: tokenData.access_token,
+      user: tokenData.user,
+    });
+  } catch (error) {
+    console.error("[Exchange Token] Error:", error);
+    return res.status(500).json({
+      error: "Failed to exchange token",
+      details: String(error),
+    });
+  }
+}