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Should telefunc work with Vercel & other serverless platforms?

See original GitHub issue

Hi Rom, I’m struggling to get telefunc to work with vite-plugin-ssr and vercel.

I started from the example at and I added telefunc as illustrated in I added a button on the home page which is meant to call a telefunc function - and this works in the dev express server.

To make it work in Vercel I added a check to the vercel handler: if (url.startsWith('/_telefunc')) {} and called the telefunc handler in there. I also imported ../dist/server/importTelefuncFiles.js in vercel/render.js a la the similar import ../dist/server/importBuild.js but really not sure whether I should’ve or not.

Regardless, something does not quite work with the deploy step - see the following function log:

Request to url: /_telefunc
2022-02-11T12:01:53.645Z	47057682-17e9-45ed-a95b-574f2f269df7	ERROR	Error: [telefunc@0.1.10][Wrong Usage] Make sure to run `vite build && vite build --ssr` before running your Node.js server with `createTelefuncCaller({ isProduction: true })`. (Build file /var/task/dist/server/importTelefuncFiles.js is missing.)
    at loadViteEntry (/var/task/index.js:62944:33)
    at loadTelefuncFilesWithVite (/var/task/index.js:62906:67)
    at loadTelefuncFiles (/var/task/index.js:61781:74)
    at runTelefunc_ (/var/task/index.js:61431:108)
    at runTelefunc (/var/task/index.js:61403:22)
    at telefunc (/var/task/index.js:62341:62)
    at Server.handler (/var/task/index.js:68307:32)

Should this work? Do you have any advice about how to proceed?


Issue Analytics

  • State:closed
  • Created 2 years ago
  • Comments:17 (13 by maintainers)

github_iconTop GitHub Comments

brilloutcommented, Feb 18, 2022

Vercel now works out-of-the-box, with both techniques. And no need to import importBuild.js anymore (for Telefunc; you still need to do this for vite-plugin-ssr).


brilloutcommented, Feb 14, 2022

Alright, this works:

It uses the “old” technique which is not outdated at all; it’s just what vps officially recommended a while ago.

Using Vercel’s Filesystem API (the “new” technique) will also work with Telefunc. (I’ve found why it currently fails and I’ll implement the fix this week.)

After further digging, I think the api/ way (the “old” technique) makes more sense also for vps, so I will actuallly change the official vps recommendation back to the “old” technique.

I’m leaving this ticket open for tracking Filesystem API support and adding documentation to

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