vercel/next.js / errors / invalid-route-source.mdx

---

title: 'Invalid Custom Route source'

Why This Error Occurred

A pattern could not be parsed when defining custom routes or a proxy matcher.

This could have been due to trying to use normal RegExp syntax like negative lookaheads (?!exclude) without following path-to-regexp's syntax.

Possible Ways to Fix It

Wrap the RegExp part of your source as an un-named parameter.

Custom Routes

Before

{
  source: '/feedback/(?!general)',
  destination: '/feedback/general'
}

After

{
  source: '/feedback/((?!general).*)',
  destination: '/feedback/general'
}

Proxy

Before

const config = {
  matcher: '/feedback/(?!general)',
}

After

const config = {
  matcher: '/feedback/((?!general).*)',
}

Useful Links

• path-to-regexp
• un-named parameters