Trazo

Enhanced chart widgets for ratatui terminal UIs.

ratatui's built-in chart widgets (Chart, BarChart, Sparkline) are functional but limited. Trazo extends them with stacked and grouped bars, candlesticks, heatmaps, area plots, richer axes with auto-tick and date formatting — all as drop-in widgets that implement ratatui::widgets::Widget.

Status: early development. 0.0.x is published on crates.io to claim the name and unblock downstream Cargo.toml entries; no widgets are usable yet and APIs will break freely between 0.0.x releases.

Motivation

Capability	`ratatui::widgets` 0.30	`trazo` (planned)
Stacked bars	—	✓
Grouped bars (side-by-side)	partial	✓
Percent-stacked bars	—	✓
Candlestick (OHLC)	—	✓
Heatmap	—	✓
Area / stacked area	—	✓
Negative bar values	—	✓
Auto-tick axes	—	✓
Date / time axes	manual	✓
`f64` data	`u64` only	✓

Roadmap

Widgets land one at a time. Each starts from a design document in docs/design/ with API rationale, ASCII mockups, and open questions:

BarChart — single + stacked first, then grouped + percent-stacked. (design)
Render styles & interactive playground — pluggable backends (ascii, ascii+color, half-block, octants, braille) and a cargo run --example playground TUI to test them live. (design)
AreaChart — single + stacked area.
Candlestick — OHLC, optional volume sub-chart.
Heatmap — sequential and diverging palettes.
LineChart — improved over ratatui's Chart (multiple series, dual axes, markers).
Sparkline — improved (multiple series, thresholds).
Axes — auto-tick, date/time formatting, log scale (extracted once two widgets share it).
Legend — shared widget (extracted once two widgets share it).

Compatibility

Targets ratatui 0.30. Once trazo ships its first widget, a tested matrix will track ratatui releases.

Documentation

API reference: https://docs.rs/trazo (once published).
Design documents: docs/design/.

License

Dual-licensed under either of

Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.