Teaching Antigravity to Direct: A Stateful Video-Editing Skill Built on Gemini's Interactions API and MCP

TL;DR: omni-skill-agy wraps Google's gemini-omni-flash-preview model (Omni Flash) in a tiny FastMCP server and packages it as an Antigravity CLI skill. You type "generate a video of a fox running through snow" into Antigravity, and it just... does it. Then you say "make it nighttime with snowfall" and it edits the same video without re-prompting the whole scene. It can also animate a still image, interpolate between two keyframes, restyle a video you already have — and when you're happy, upload the result to YouTube. Without leaving your terminal. Background: why another video tool? Most video-generation workflows are stateless . You send a prompt, you get frames back, and the model immediately forgets everything. Want to tweak the result? You re-describe the entire scene and pray the character, lighting, and camera work survive the round trip. (Narrator: they don't.) Google's Omni Flash — gemini-omni-flash-preview — takes a different approach. It's the video-generation model in Google's Gemini "Omni" line: built for fast, high-fidelity clips, and — the headline feature — wired into the stateful Interactions API , which lets you iterate on a video across multiple turns while the model keeps the visual context server-side. What Omni Flash actually does The "Omni" part isn't branding fluff — the model accepts genuinely mixed multimodal input. A single request's input can be a plain string, or a list of typed parts: text parts, base64-encoded image parts, and document parts pointing at a video you've uploaded via the Gemini File API. The model composes whatever you hand it into one clip. That single mechanism covers five distinct ways to make a video: Text → video. A prompt in, an .mp4 out — landscape 16:9 or portrait 9:16 , chosen at generation time. One image + a motion prompt → animation. A still comes to life ("the group smiles and waves at the camera"). Two images + a transition prompt → keyframe interpolation. The model invents the in-between footage from frame A