eye-declare

Introduction #

eye-declare is a declarative, React-like TUI rendering library for Rust, built on Ratatui. It provides a component model for building terminal UIs that render inline — content grows into the terminal's native scrollback rather than taking over the full screen.

Why inline rendering? #

Traditional TUI frameworks (Ratatui's Terminal, cursive, tui-realm) operate in full-screen mode: they claim the entire terminal viewport and redraw it on every frame. This works well for dashboards and editors, but it's the wrong model for tools where output accumulates:

  • AI assistants — streaming responses should persist in scrollback
  • Build tools — earlier task output should remain visible
  • Interactive prompts — submitted answers shouldn't disappear
  • CLI tools — output should behave like normal terminal programs

eye-declare's inline rendering model treats the terminal like a document that grows downward. New content appears below old content, and earlier rows naturally scroll into the terminal's scrollback buffer. This means your TUI output coexists with regular shell output — no alternate screen, no viewport takeover.

The programming model #

If you've used React, the mental model will feel familiar:

  1. State — your application data, owned by the framework
  2. View function — a pure function that maps state to a component tree
  3. Components — reusable UI building blocks with props and internal state
  4. Reconciliation — the framework diffs old and new trees, preserving component state across rebuilds
use eye_declare::{element, Application, Elements, Spinner, TextBlock};



struct AppState {

    messages: Vec<String>,

    loading: bool,

}



fn view(state: &AppState) -> Elements {

    element! {

        #(for msg in &state.messages {

            TextBlock {

                Line { Span(text: msg.clone()) }

            }

        })

        #(if state.loading {

            Spinner(label: "Working...")

        })

    }

}

The element! macro provides JSX-like syntax. Components are Rust structs that implement the Component trait. State is automatically tracked for dirty detection, so only changed components re-render.

What eye-declare is not #

  • Not a full-screen TUI framework — if you need a fixed viewport with scrollable panes, use Ratatui directly
  • Not a widget library — it provides a small set of built-in components; the value is in the rendering model and component system
  • Not stable yet — the API is evolving; expect breaking changes before 1.0

Built on Ratatui #

eye-declare uses Ratatui's buffer, cell, style, and widget primitives internally. Components render into Ratatui Buffers, and you can use any Ratatui Widget inside a component's render() method. If you know Ratatui, you already know how to draw things — eye-declare adds the component model, reconciliation, and inline rendering on top.

Next steps #