How to make a narrated explainer video for a side project from one prompt

My tool pages explained everything in text, and I wasn't going to record and edit a video for each of them by hand.

I used Animator, a Python CLI that turns one prompt into a hand-drawn whiteboard video with narration:

bash

pip install -r requirements.txt   # plus FFmpeg on PATH and GEMINI_API_KEY in .env
python -m animator --prompt "How tabs-broadcast lets browser tabs talk to each other" --scenes 4 -o tabs_broadcast.mp4

Gemini writes the storyboard, draws each scene, voices it and finds every icon in the frame. A local CPU engine then draws each icon while its sentence is being spoken. A 4–5 scene video takes about a minute.

That's how I got the videos on tabs-broadcast, XPLOIT Game UI, Steam AI Disclosure and Contract Red-Flag Scanner: one command each, uploaded to YouTube as is.

If a caption shows up before it's spoken, rerun with --save-storyboard and fix the beat in scene_XX.regions.json. The art style and the script tone are plain-text prompts in animator/prompts/, so you can change them without touching code.

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