I have a relatively simple setup that essentially bundles some source code and outputs to dist using esbuild. This works and I can see it in the output tab of my function.

However, when I attempt to import it from my serverless function in the api folder, i.e. "api/x.ts", it cannot find the module.

The code itself is very simple for x.ts

1
export { GET } from "../handler.js"

with the output directory structure being: api/ ├─ x.js ├─ middleware handler.js middleware

This is running on node 22.x. I cannot determine why I cannot import handler.js from my serverless function. I've added "includeFiles": "handler.js" to my vercel.json.

The actual error is: Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/var/task/handler.js' imported from /var/task/api/x.js

Thank you