Ilha is a UI library built for a weird constraint: it needs to fit inside an AI context window. The project appeared on Hacker News this week.
The problem is real. Traditional HTML, CSS, and JavaScript eat through tokens fast. token overhead as a potential downside. When context windows have hard limits, that difference decides whether an AI agent can reason about your interface at all.
Ilha swaps verbose HTML for symbolic shorthand. Instead of spelling out full element tags and style attributes, it uses condensed tokens that carry the same structural meaning. AI models can read layout and hierarchy without wading through markup soup.
Developers plan to test it with Claude and other models. A few spotted bugs already, including a non-functional "Get Started" button on the landing page. A broken button on a UI library's own site isn't a great sign. But the concept has people interested enough to look past it.
Most agents today work with APIs and text, not interfaces. If that changes and agents start browsing the web or building apps visually, compact UI formats like Ilha become a lot more relevant. Ilha is betting it happens.