final version

apps/web/app/deeplink/[url]/page.tsx

@@ -1,7 +1,37 @@
 export const runtime = "edge";
 
 export default function DeepLinkPage({ params }: { params: { url: string } }) {
-  const url = decodeURIComponent(params.url).replace(/\+/g, " ");
+  // First decode the full URL parameter from the route
+  const url = decodeURIComponent(params.url);
+  // Split into base URL and query string
+  const [front, query] = url.split("?");
 
-  return <meta httpEquiv="refresh" content={`0; url=${url}`} />;
+  let redirectUrl = url;
+
+  // if there are query parameters, we need to process them
+  if (query) {
+    // Parse the query string (but don't use toString() later as it adds extra encoding)
+    const queryParams = new URLSearchParams(query);
+
+    // Process each parameter with proper encoding
+    const processedParams = Array.from(queryParams.entries()).map(
+      ([key, value]) => {
+        // Handle form-encoded spaces ('+' → ' ')
+        const decodedFromForm = value.replace(/\+/g, " ");
+        // Decode any existing percent-encoding (e.g., '%26' → '&')
+        const fullyDecoded = decodeURIComponent(decodedFromForm);
+        // Apply one clean round of encoding
+        const encoded = encodeURIComponent(fullyDecoded);
+
+        return `${key}=${encoded}`;
+      },
+    );
+
+    // Reconstruct the URL with properly encoded parameters
+    redirectUrl = `${front}?${processedParams.join("&")}`;
+  }
+
+  // Redirect to the redirect URL (which may be the same as the original URL,
+  // or a cleaned-up version with properly encoded parameters)
+  return <meta httpEquiv="refresh" content={`0; url=${redirectUrl}`} />;
 }