Making Dynamic MDX Blogs Work with OpenNext on Cloudflare Workers

I ran into a small but annoying problem while deploying a Next.js MDX blog to Cloudflare Workers with OpenNext.

The blog worked locally. The build passed. OpenNext even listed the blog routes during the build.

Then I opened the deployed site, and the blog page was empty.

The issue was not MDX. It was not frontmatter. It was not a missing route. The real problem was that my blog code was still thinking like a normal Node.js app, while Cloudflare Workers runs from a bundled Worker output.

The Short Version