Leptos is a full-stack Rust web framework designed for building reactive applications that share logic and types between the server and the browser. It provides a comprehensive toolkit for developing web interfaces where specific DOM nodes update automatically in response to changes in underlying reactive signals, rather than re-rendering entire component trees.
The framework distinguishes itself through a fine-grained reactivity model that tracks dependencies at the individual data point level. It utilizes compile-time template transformation to convert declarative HTML-like syntax into optimized imperative instructions, and supports isomorphic server-side rendering with streaming HTML delivery. By employing component-based hydration islands, it minimizes the amount of JavaScript sent to the client, attaching interactivity only where necessary.
Beyond its core rendering model, the project covers a broad surface of full-stack capabilities, including type-safe remote procedure calls that allow client-side code to invoke server-side functions directly. It integrates asynchronous data management, nested routing, and state synchronization between the server and client, while providing tools for managing component lifecycles and memory through a reactive ownership tree.
The framework includes a CLI for bootstrapping projects, orchestrating full-stack builds, and automating development cycles with live recompilation. It is documented to support various deployment strategies, including static hosting, containerized server-side applications, and serverless environments.