Simplified Discord interactions endpoint

cgen-fff869494de045faa8711d66edc6bab2

api/discord/interactions.ts

@@ -1,31 +1,10 @@
 import { VercelRequest, VercelResponse } from "@vercel/node";
 import { createVerify } from "crypto";
 
-export const config = {
-  api: {
-    bodyParser: {
-      raw: {
-        type: "application/json",
-      },
-    },
-  },
-};
-
 export default function handler(req: VercelRequest, res: VercelResponse) {
-  // Set CORS headers for Discord
   res.setHeader("Access-Control-Allow-Origin", "*");
-  res.setHeader("Access-Control-Allow-Methods", "POST, OPTIONS");
-  res.setHeader(
-    "Access-Control-Allow-Headers",
-    "Content-Type, x-signature-ed25519, x-signature-timestamp",
-  );
-
-  if (req.method === "OPTIONS") {
-    return res.status(200).end();
-  }
 
   if (req.method !== "POST") {
-    res.setHeader("Allow", "POST, OPTIONS");
     return res.status(405).json({ error: "Method not allowed" });
   }
 
@@ -34,71 +13,55 @@ export default function handler(req: VercelRequest, res: VercelResponse) {
     const timestamp = req.headers["x-signature-timestamp"] as string;
     const publicKey = process.env.DISCORD_PUBLIC_KEY;
 
-    console.log("[Discord] Interaction received");
-    console.log("[Discord] Has signature:", !!signature);
-    console.log("[Discord] Has timestamp:", !!timestamp);
-    console.log("[Discord] Has public key:", !!publicKey);
-
-    if (!publicKey) {
-      console.error("[Discord] DISCORD_PUBLIC_KEY not set");
-      return res.status(500).json({ error: "Server not configured" });
+    if (!signature || !timestamp || !publicKey) {
+      console.error("[Discord] Missing signature, timestamp, or public key");
+      return res.status(401).json({ error: "Unauthorized" });
     }
 
-    if (!signature || !timestamp) {
-      console.error("[Discord] Missing required headers");
-      return res.status(401).json({ error: "Invalid request" });
+    // Reconstruct raw body exactly as Discord sent it
+    let rawBody: string;
+    if (typeof req.body === "string") {
+      rawBody = req.body;
+    } else {
+      rawBody = JSON.stringify(req.body);
     }
 
-    // Get raw body - Vercel sends it as Buffer with raw: true config
-    const rawBody =
-      req.body instanceof Buffer
-        ? req.body.toString("utf8")
-        : typeof req.body === "string"
-          ? req.body
-          : JSON.stringify(req.body);
-
-    // Verify signature
+    // Create message for signature verification
     const message = `${timestamp}${rawBody}`;
-    console.log(
-      "[Discord] Verifying signature for message length:",
-      message.length,
-    );
 
-    const signatureBuffer = Buffer.from(signature, "hex");
-    const verifier = createVerify("ed25519");
-    verifier.update(message);
-    const isValid = verifier.verify(publicKey, signatureBuffer);
-
-    if (!isValid) {
-      console.error("[Discord] Signature verification failed");
-      return res.status(401).json({ error: "Invalid signature" });
-    }
-
-    console.log("[Discord] Signature verified successfully");
-
-    let interaction;
+    // Verify Discord's signature
     try {
-      interaction = typeof rawBody === "string" ? JSON.parse(rawBody) : rawBody;
-    } catch {
-      console.error("[Discord] Failed to parse JSON body");
-      return res.status(400).json({ error: "Invalid JSON" });
+      const signatureBuffer = Buffer.from(signature, "hex");
+      const verifier = createVerify("ed25519");
+      verifier.update(message);
+      const isValid = verifier.verify(publicKey, signatureBuffer);
+
+      if (!isValid) {
+        console.error("[Discord] Signature verification failed");
+        return res.status(401).json({ error: "Invalid signature" });
+      }
+    } catch (err: any) {
+      console.error("[Discord] Signature verification error:", err.message);
+      return res.status(401).json({ error: "Signature error" });
     }
 
-    console.log("[Discord] Interaction type:", interaction?.type);
+    // Parse interaction
+    const interaction = JSON.parse(rawBody);
 
-    // Discord sends a PING to verify the endpoint
-    if (interaction?.type === 1) {
+    // Respond to PING with type 1
+    if (interaction.type === 1) {
       console.log("[Discord] ✓ PING verified");
       return res.status(200).json({ type: 1 });
     }
 
-    // For all other interactions, acknowledge them
+    // Handle other interaction types
+    console.log("[Discord] Interaction type:", interaction.type);
     return res.status(200).json({
       type: 4,
-      data: { content: "Interaction received" },
+      data: { content: "Pong!" },
     });
   } catch (err: any) {
-    console.error("[Discord] Error:", err?.message, err?.stack);
-    return res.status(500).json({ error: "Server error" });
+    console.error("[Discord] Error:", err?.message);
+    return res.status(500).json({ error: "Internal server error" });
   }
 }