A GPU-backed terminal emulator, written from scratch in Rust — documenting itself.
OdyTTY is a terminal emulator we're building from scratch, in Rust. It's
GPU-backed (wgpu/Vulkan) and meant to be quick, sturdy, and pleasant enough to live
in all day.
The unusual part is what's underneath: we wrote the whole stack ourselves. Every byte — from the pseudo-terminal all the way to the pixel on your screen — runs through our own code instead of someone else's library.
The PTY layer uses rustix directly for openpt/grantpt/unlockpt
and session-leader spawn. The VT parser is a clean-room two-layer pipeline built from primary
specifications (vt100.net, ECMA-48, xterm ctlseqs) — not derived from vte
or any other terminal's source. vte, portable-pty, and crossterm
are not in the dependency tree. External crates handle only font rasterization, the GPU API,
windowing, and clipboard transport — the same boundary mature independent terminals draw.
We're building on Linux first, but OdyTTY isn't meant to stay there.
A few things most terminals don't do — or at least, not all at once, and not on top of their own code.
Full cluster rendering via swash: ZWJ family sequences, flag pairs,
skin-tone modifiers, keycap sequences, and VS15/VS16 variation-selector policy.
Noto Color Emoji CBDT/CBLC bitmaps in a dedicated premultiplied-RGBA atlas. Emoji pixels
are never SGR-tinted.
The full Kitty APC graphics surface (actions t/T/p/d/q, RGB/RGBA + PNG,
direct / file / shared-memory transports, placements, z-index, crop, cell scaling) plus a
complete Sixel data language with the VT340 palette and DECSDM.
Progressive enhancement as a negotiated overlay: disambiguation, event types
(press/repeat/release), alternate keys, report-all, associated text. Bounded stack;
RIS/DECSTR resets it. At flags 0 the output is byte-identical to
legacy key encoding.
End-to-end pixel mouse reporting: DECSET/DECRST/DECRQM
wired, native pixel-to-cell seam closed, reports emitted as
CSI < Cb ; Px ; Py M|m with true physical pixel coordinates.
A full 16-color ANSI palette plus semantic roles (cursor, selection, search, border).
53 contrast-validated built-ins, OSC-4 / OSC-10/11/12 dynamic
overrides with correct precedence, and a dependency-free .theme file format for
your own.
An off-by-default visual treatment — minimum-contrast lift, stem darkening, focus dimming, bloom, and a CRT pass (scanlines + vignette) — all gated behind explicit settings. Readability first; atmosphere on request.
Comprehensive VT coverage: SGR (256-color + truecolor, colon and semicolon forms), cursor movement and position reports, scroll regions (DECSTBM/DECOM), alternate screen (47/1047/1048/1049), mouse modes 9/1000/1002/1003 with encodings 1005/1006/1015/1016, focus reporting (1004), DECSCUSR, OSC 0/2 titles, wide-character handling, rectangle ops (DECCRA/DECFRA/DECERA/DECCARA), XTGETTCAP, DECRQSS, and bracketed paste. See protocols.
Building OdyTTY takes Cargo and a Vulkan-capable GPU. For now that means Linux — Wayland, or X11 through XWayland.
# clone, then from the repo root:
cargo build --release
cargo run -- --native# larger text with the Odyssey theme
ODYTTY_FONT_SIZE=18 ODYTTY_THEME=odyssey cargo run -- --native
# a custom font family
ODYTTY_FONT_FAMILY="DejaVu Sans Mono" cargo run -- --native
# RGB subpixel antialiasing
ODYTTY_SUBPIXEL=rgb cargo run -- --nativeodytty --list-themes # stable name / appearance / family rows
odytty --show-config # effective merged config as key=value linesConfiguration resolves defaults → ~/.config/odytty/odytty.conf → environment;
environment variables always win. The native app polls the config file about once per second for
live reloads. See config for the full knob reference.
Most of the time you won't come here — OdyTTY is configured from an in-app settings panel, so
you pick options and watch them take effect rather than editing a file by hand. But everything
that panel touches is also a plain key = value setting (and an environment variable),
and this is the complete list. It's generated straight from OdyTTY's
docs/runtime-knobs.md, so it never drifts from the real thing.
Loading the knob reference…
OdyTTY ships 53 built-in themes, each a full
appearance profile: default fg/bg, the window clear color, the 16-color ANSI palette, and semantic
roles. Click any theme to wear it — the whole page reskins live, including the
CRT field's hue. That is the same data the terminal loads; the gallery is generated from the real
.theme files.
Loading the theme gallery…
.theme file formatA theme is a plain text file of key = value lines. Drop one in
~/.config/odytty/themes/ and select it with theme = myname or point
ODYTTY_THEME at a path. A bad or missing theme never prevents startup — OdyTTY
falls back to plain and logs a warning.
name = example
appearance = dark
foreground = #d6def4
background = #0c1224
clear = #070b18
cursor = #86c1ff
selection = #243352
search = #4a4018
color0 = #12182a # ANSI black
color1 = #e06b74 # red
# … color2 – color15 …The default keyboard surface. You can rebind any of it from the settings panel, or via
ODYTTY_KEYBINDS / the keybinds config key
(e.g. ctrl+shift+y=copy;ctrl+shift+p=paste).
| Chord | Action |
|---|---|
| Ctrl+Shift+F | Scrollback search (next/prev, match highlights) |
| Ctrl+Shift+T | Theme picker — arrow to preview, Enter to keep, Esc to restore |
| Ctrl+Shift+, | In-app settings panel (font, theme, cursor, all knobs) |
| Ctrl+S (in panel) | Write changed rows back to odytty.conf (preservation-first) |
| Ctrl+Shift+Y | Copy selection (default; rebindable) |
| Ctrl+Shift+P | Paste (default; rebindable) |
| Double-click | Select word · Triple-click selects line |
| Ctrl+Click | Open OSC 8 hyperlink via xdg-open (scheme allowlist) |
What OdyTTY understands on the wire, for reference. Everything ticked here is verified by the test suite.
t/T/p/d/qf=24/f=32) & PNG (f=100)DCS q) — RGB/HLS, repeat, raster attrs, VT340 palette, DECSDM4:0–4:5) + underline color (58/59)No. OdyTTY renders crisp by default — its plain theme is xterm-exact and
all CRT/bloom/ambient effects are off until you enable them. The CRT look on this site is OdyTTY's
own opt-in visual layer, turned up as a showpiece. Hit plain in the visual-layer
control to strip it back to the shipped appearance.
Two things, mostly. First, it's menu-driven: you set it up from an in-app settings panel and a live theme picker — pick an option, watch it apply — instead of hunting through a config file in another window. (There's still a config file underneath, and the panel writes to it, so power users keep everything they'd want; you just rarely have to touch it.)
Second, it owns its whole stack — the pseudo-terminal layer, the parser, the model, the
renderer, the shaders — rather than wrapping an existing library like vte or
portable-pty. That, together with live color emoji, Kitty graphics and Sixel, the
Kitty keyboard protocol, pixel-precise mouse reporting, and 53
built-in themes, is a combination you don't often see in one place.
Today, Linux with a Vulkan-capable GPU (Wayland natively, X11 via XWayland). macOS support is a first-class goal we're actively working toward, and Windows is on the roadmap for a future release.
OdyTTY is GPL-3.0-only and uses a DCO sign-off workflow (see CONTRIBUTING.md in the
repository).
This page is a static site (Vite → Cloudflare Pages). The CRT field is a raw
WebGL shader; the theme gallery and knob table are generated from OdyTTY's real .theme
files and runtime-knobs.md by a small awk pipeline. It steals its tube from its sibling,
unfinished-works.com — same workshop,
different machine.