Allow server function to return ReadableStream

[lcswillems]

Goals

I want to stream data from server to client, and would like to use a ReadableStream for this.

Background

Don't know background.

Proposal

Allow server function to return ReadableStream.

[FraserMuir]

To put some context around this (as I believe I am facing the same issue) we're looking to be able to return ReadableStream objects from Server Actions. I believe this is an impossibility with the current architecture due to how the return values are serialized from Server Actions. I get the following at runtime when attempting to do exactly that:

It would be good to understand if this is just a temporary limitation that could be solved with some tweaks / additions, or if it's fundamentally impossible. Either way, updating the docs to make this limitation more visible would be ideal: https://nextjs.org/docs/app/building-your-application/data-fetching/server-actions

[aleksa-codes]

I am facing this right now, any updates? I am trying to pass stream.toReadableStream(); using OpenAI from server action to the client.

[yudistiraashadi]

I believe this is possible since Vercel's AI SDK has stream from server function link