Runway Gen-4.5 API Tutorial: Generate AI Videos in 3 Lines of Code (Python & JavaScript)

Runway Gen-4.5 API Tutorial: Generate AI Videos in 3 Lines of Code (Python & JavaScript) Runway Gen-4.5 is making waves in the AI video generation space. Developers who've seen the outputs are impressed — cinematic quality, smooth motion, excellent prompt adherence. If you're building video generation into your app, you need to know how to access it via API. This tutorial shows you how to use the Runway Gen-4.5 API through NexaAPI — the cheapest and fastest way to access 56+ AI models including Runway's latest. What is Runway Gen-4.5? Runway Gen-4.5 is the latest iteration of Runway ML's text-to-video model, offering: Cinematic quality video generation from text prompts Smooth motion with improved temporal consistency Better prompt adherence compared to Gen-3/Gen-4 Support for various resolutions (720p, 1080p) 4-16 second video clips The model is available on Replicate as runwayml/gen-4.5 , but accessing it through NexaAPI gives you better pricing and no cold start delays. Why Use Nexa