Documentation: https://vercel.com/docs/functions/serverless-functions/runtimes/node-js#advanced-node.js-usage Vercel expects you to export a function whose signature is compatible with the argument to Node.js [`createServer`](https://nodejs.org/api/http.html#httpcreateserveroptions-requestlistener) method. Fortunately there is already an implementation of such a function in http4s. https://github.com/http4s/http4s/blob/ec939b1b354843d53293d4f9a9ac0e205fd4ec47/client-testkit/js/src/main/scala/org/http4s/client/testkit/scaffold/ServerScaffold.scala#L70-L72
Documentation: https://vercel.com/docs/functions/serverless-functions/runtimes/node-js#advanced-node.js-usage
Vercel expects you to export a function whose signature is compatible with the argument to Node.js
createServermethod.Fortunately there is already an implementation of such a function in http4s.
https://github.com/http4s/http4s/blob/ec939b1b354843d53293d4f9a9ac0e205fd4ec47/client-testkit/js/src/main/scala/org/http4s/client/testkit/scaffold/ServerScaffold.scala#L70-L72