Signal with start external workflow

What’s the best way to signal with start a workflow from another workflow?

My usecase:
I have a client that starts a video export workflow, this workflow needs to request a lot of small chunks which it combines into a video file. Some of these chunks might already exist, some might need to be rendered on the fly.

I want to have a single “render manager” workflow that receives these requests, prioritizes them on some metadata and executes them in activities directly or in child workflows. When the render is done, it should signal the waiting request workflows that need that render so they can finish their tasks with these renders.

I’ve read about the “signal reply” pattern and I thought it could make sense here.

The render manager workflow could auto close if there’s no requests in it’s in-code queue.

Sources:

So I thought I could signalwithstart the renderer-manager workflow with a new render request, but this is only available from a client. In my case the client doesn’t need to know about the individual renders, it just wants to start an export.

Should I hack this by calling signalwithstart in an activity, or is there a better pattern that I’m missing?

Right now I’m just firing it in an activity, and that seems to work alright.

Seems this is the confirmed way to do it, so closing this.