RunAPI is a unified inference API that routes requests across image, video, audio, and text generation models through a single endpoint and a single bill. The vendor states it is designed for high-volume workloads where per-request cost efficiency matters more than model-provider loyalty. Teams prototyping across modalities can swap providers without rewriting integration code. The ceiling appears when you need fine-grained control over model behavior, custom fine-tuned weights, or self-hosted deployment — none of which are available here. At that point, teams move request routing back in-house and use provider SDKs directly.