Runway Solaris is an interface world model that generates working software interfaces frame by frame in real-time, announced by Runway on August 31, 2026 for designers and product teams who want to prototype interactive experiences without writing a line of front-end code. Instead of producing HTML or React, Solaris renders each screen as a continuous video-like stream that reacts to clicks, drags, and typed commands.
Core Features
- Frame-by-frame rendering: a paired language model decides what the interface should do next, and Solaris paints the result at 720p with roughly 37 ms latency.
- No code layer: there is no DOM, CSS, or JavaScript behind the visuals, so fidelity lost when translating mockups into layouts is preserved.
- Built on Gen-4.5: Runway adapted its Gen-4.5 video model with autoregressive generation, denoising distillation, and self-training for long-session coherence.
- Open-ended interaction: natural-language instructions can redefine what an object does mid-session, not just trigger a fixed menu.
- Agent-training substrate: variable environments let computer-use agents practice against interfaces that change while the task stays the same.
In Runway's launch study of 250 participants across 30 interaction examples, people preferred Solaris over interfaces coded live by Claude Opus 5, 61% to 24% on following instructions and 71% to 21% on natural behavior.
Use Cases
- Product showrooms and interactive tutorials where the scene reacts to a user's actions.
- Rapid UX prototyping before any engineering team is involved.
- Synthetic environments for training and testing UI-operating agents.
Pricing
Solaris is an early-access research model offered by request; Runway has published no standalone public price or API. General Runway plans that include Gen-4.5 start at $12 per month, and a free tier exists for lighter use. Treat any 'Solaris API key' offer as unverified until Runway ships public terms.
Our Take
Best for teams exploring post-code UI prototyping and agent training. The trade-off is real: generated interfaces cannot guarantee button identity, transaction safety, or accessibility, so it is not a production front-end yet.
