beer

beer is a small Wayland-native terminal emulator written in Rust. It renders through wl_shm with the CPU, uses a real PTY for the child shell, and keeps the architecture close to the model used by terminals like foot: no GPU renderer, no tabs, no ligatures, and no async runtime.

The project is still pre-1.0, but it is already usable as a single-window terminal on Wayland.

Features

• Software-rendered Wayland window with server-side decoration negotiation.
• PTY-backed login shell with resize propagation through TIOCSWINSZ.
• VT parsing through vte, including cursor movement, erase/edit operations, scroll regions, alternate screen, SGR attributes, truecolor, 256-color, OSC palette/theme escapes, title updates, DA/DSR, XTGETTCAP, and synchronized output.
• Font discovery and rasterization through fontconfig and FreeType, including fallback faces, styled variants, bounded glyph caching, and color emoji.
• Scrollback with wheel and key scrolling, reflow on resize, and incremental search.
• Mouse selection with word, line, and rectangular selection; clipboard and primary-selection integration; bracketed paste; OSC 52 set/query.
• Mouse and focus reporting for terminal applications.
• TOML configuration with live reload on SIGUSR1.
• Shell integration through OSC 7 and OSC 133 for cwd-aware new windows, prompt jumping, and piping the last command's output.
• OSC 8 hyperlinks, visible URL hint mode, and OSC 9/777/99 notifications.

Not Implemented Yet

• Daemon/server mode and client mode.
• Kitty keyboard protocol and Unicode codepoint input mode.
• Touchscreen input.
• Conformance and performance hardening passes beyond the current unit tests.

Build

The repository provides a Nix dev shell with the Rust toolchain and native Wayland/font dependencies:

# Enter the development shell.
$ nix develop

# Build an optimized local binary.
$ cargo build --release

The Nix package builds the binary, terminfo entry, and man pages:

# Build the Nix package.
$ nix build

Run

From a Wayland session:

# Start Beer from your terminal.
$ beer

or after a release build:

# Run the release binary directly.
$ ./target/release/beer

Useful flags:

# Pass a config file to Beer.
$ beer --config /path/to/beer.toml

# Check the version with -V or --version.
$ beer --version

# See the help text.
$ beer --help

--server exists as a future mode switch and currently returns an error.

Configuration

By default, beer reads:

$XDG_CONFIG_HOME/beer/beer.toml

or, if XDG_CONFIG_HOME is unset:

~/.config/beer/beer.toml

A missing file uses defaults. A malformed file logs a warning and falls back to defaults. Unknown keys are ignored for forward compatibility.

Example:

[main]
font = "monospace"
font-size = 16
pad-x = 2
pad-y = 2

[colors]
background = "#181818"
foreground = "#c5c8c6"
alpha = 1.0

[key-bindings]
"Ctrl+Shift+C" = "copy"
"Ctrl+Shift+V" = "paste"
"Ctrl+Shift+F" = "search"

[url]
launch = ["xdg-open"]

See doc/beer.toml.5.scd for the full configuration reference.

Development

The expected verification set is:

# Check Rust formatting.
$ cargo fmt --all -- --check

# Run Clippy with warnings denied.
$ cargo clippy --all-targets --all-features -- -D warnings

# Build a release-optimized binary.
$ cargo build --release

# Run the test suite.
$ cargo test

# Check dependency policy.
$ cargo deny check

# Verify the Nix package.
$ nix build

The code is organized as a single crate with internal modules for the PTY, VT model, grid, font pipeline, renderer, input encoding, configuration, and Wayland frontend. Keep feature logic in the module that owns the concept; avoid adding more state directly to the Wayland event root or the core grid when a focused submodule can own it.

License

EUPL-1.2.