Explainroo

Explainroo is a free, open source video-generation kit for people who want an AI coding agent to make short explainer videos or product demos. The workflow is intentionally agent-first. You ask Claude Code, Codex, Pi, or another coding agent for a video, point it at the repository, and the agent writes the narration and canvas scenes that Explainroo turns into an MP4. The official site says the voice, timing, and rendering run on your own computer, so the base video pipeline does not require a hosted rendering service. The tool combines several local pieces. Kokoro provides text-to-speech with local voices. Whisper, through the JavaScript stack, creates word-level timing so scenes can react to the exact spoken words. Chrome or Chromium renders canvas frames with Playwright, while ffmpeg assembles audio, video, music, and effects into the final file. The project also includes Rough.js and Lucide-based drawing helpers so an agent can build animated diagrams without designing every primitive from scratch. Optional image generation through OpenRouter can be used when a video needs generated artwork, but the core path remains local. Explainroo is strongest for builders who need quick visual explanations: product demos, internal walkthroughs, onboarding clips, launch videos, and educational explainers. Instead of hand-editing a timeline, the user gives a topic and lets the agent create `script.md`, `scenes.js`, and the project settings. The docs cover getting started, scene references, looks, captions, commands, settings, image handling, and quality checks. The README also provides a copy-paste prompt for agents: ask for a short explainer, clone the repo, read `AGENTS.md`, and follow the steps. A useful detail is that Explainroo tries to make quality review possible for agents that cannot watch video. It can generate still frames, contact sheets, layout checks, and pronunciation checks so the agent can catch overlapping text, cut-off elements, or words the voice struggled to say. That makes it more practical for automated iteration than a simple render script. Pricing is simple: Explainroo itself is MIT-licensed and free. Users still need their own AI coding agent, local compute, Chrome or Chromium, ffmpeg, and any optional paid image-generation provider they choose. The project is new, but its narrow focus is clear: make agent-produced explanatory MP4s faster than opening a traditional video editor. For an OpenTools page, the practical takeaway is that Explainroo is not a hosted video generator or a generic prompt wrapper. It is a developer kit that gives an agent repeatable files, commands, and checks. That makes it easier to version a video project in Git, reuse examples, and inspect exactly what the agent changed between renders.