fix: use 303 redirect for checkout POST to prevent header errors

- Changed NextResponse.redirect() to Response with 303 status
- Added .gitignore file

.gitignore

@@ -0,0 +1,40 @@
+# Dependencies
+node_modules/
+.pnpm-store/
+
+# Next.js
+.next/
+out/
+
+# Build
+dist/
+build/
+
+# Environment
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Testing
+coverage/
+
+# Misc
+*.tsbuildinfo

app/api/create-checkout-session/route.ts

@@ -86,7 +86,11 @@ export async function POST(request: NextRequest) {
       },
     })
 
-    return NextResponse.redirect(session.url!)
+    // Use 303 redirect for POST requests (tells browser to follow with GET)
+    return new Response(null, {
+      status: 303,
+      headers: { Location: session.url! },
+    })
   } catch (err) {
     console.error("Error creating checkout session:", err)
     return NextResponse.json({ error: "Error creating checkout session" }, { status: 500 })

package.json

@@ -46,7 +46,7 @@
     "embla-carousel-react": "8.5.1",
     "input-otp": "1.4.1",
     "lucide-react": "^0.454.0",
-    "next": "16.0.3",
+    "next": "16.0.10",
     "next-themes": "^0.4.6",
     "react": "19.2.0",
     "react-day-picker": "9.8.0",