Building an AI video interface looks simple in a demo: add a prompt box, an upload button, and a Generate button.
The real product work starts when those inputs mean different things.
While building MiniMaxH3.app, an independent third-party studio around the MiniMax H3 open-weight video model, we found that text-to-video, first/last frame, and multi-reference generation should not be treated as cosmetic tabs over the same form. Each workflow has a different input contract, a different failure surface, and a different definition of "control."
This post explains the implementation decisions behind those three workflows: how we normalize user intent, validate media before upload, preserve reference order, expose task state, and reserve credits without charging for failed jobs.
MiniMaxH3.app is an independent third-party project. It is not affiliated with MiniMax or Hailuo AI, and it does not distribute model weights.
