A re-frame inspired desktop UI framework built on Odin, Raylib, and LuaJIT.

Write reactive desktop apps in Fennel (or Lua) with the same dataflow model that makes re-frame a joy: single state atom, event-driven updates, path-tracked subscriptions, declarative effects. No browser, no Electron, no JS bundler.

Experimental. This project is under active reboot. APIs will change.

Stack

Layer	Technology
Host / renderer	Odin + Raylib
Scripting	LuaJIT (Lua 5.1)
App language	Fennel (or plain Lua)
AI interface	HTTP dev server

Getting started

The easiest way to start is with redin-cli:

# Install the CLI (requires Babashka)
curl -sL https://raw.githubusercontent.com/sstoehrm/redin-cli/main/install.sh | bash

# Create a Fennel project
redin-cli new-fnl my-app
cd my-app
./redinw main.fnl

# Or a Lua project
redin-cli new-lua my-app

The CLI downloads a pinned redin binary into .redin/ — no build tools needed. See redin-cli help for all commands.

Building from source

The one-step path is ./setup.sh, which installs system packages (via apt / dnf / pacman / brew), pulls submodules, and runs ./build-dev.sh. The manual equivalent is below.

# Prerequisites (Ubuntu/Debian)
sudo apt-get install -y luajit libssl-dev \
  libgl1-mesa-dev libx11-dev libxrandr-dev libxi-dev \
  libxcursor-dev libxinerama-dev

# Initialize submodules (lib/odin-http)
git submodule update --init --recursive

# Dev build (bakes in REDIN_DEV / REDIN_PROFILE / REDIN_TRACK_MEM)
./build-dev.sh

# Run — dev server starts because REDIN_DEV is compiled in.
# Exactly one positional argument is accepted; extra args exit 2.
./build/redin examples/kitchen-sink.fnl

For a release-stripped binary (no dev server, no profile, no tracker), use bare odin build instead:

odin build src/cmd/redin -collection:lib=lib -collection:luajit=vendor/luajit -out:build/redin

Dependency	Purpose	Required
Odin (nightly)	Compiles the host/renderer	Yes
Raylib	Bundled with Odin	--
LuaJIT (luajit)	Runs tests, AOT compiles Fennel; the C library is statically linked from vendor/luajit/ so libluajit-5.1-dev is not required	Yes
OpenSSL (libssl-dev)	HTTPS support via odin-http	Yes
OpenGL + X11 dev headers (Linux only — libgl1-mesa-dev, libx11-dev, libxrandr-dev, libxi-dev, libxcursor-dev, libxinerama-dev)	Required by Odin's bundled Raylib at link time	Yes (Linux)
lib/odin-http submodule	Async HTTP client used by redin.http	Yes

Test

# Fennel runtime tests
luajit test/lua/runner.lua test/lua/test_*.fnl

# Build check
odin build src/cmd/redin -collection:lib=lib -collection:luajit=vendor/luajit -out:build/redin

UI integration tests additionally need Babashka (bb), and xvfb for headless runs:

sudo apt-get install -y xvfb
bash test/ui/run-all.sh --headless

Project structure

src/cmd/redin/           Thin CLI entry (package main)
  main.odin              Arg parsing, calls redin.run
src/redin/               Importable framework (package redin)
  runtime.odin           Public API + main loop
  render.odin            Raylib renderer
  bridge/                Lua/Fennel bridge
  canvas/                Canvas provider system
  input/                 Input handling
  types/                 Shared type definitions
src/runtime/             Fennel runtime modules
examples/                Demo apps
test/lua/                Fennel unit tests
test/ui/                 UI integration tests (Babashka)
.claude/skills/          Claude Code development skills
docs/                    Documentation

Documentation

Guides

• Quickstart
• Building Apps
• Re-frame Quickstart
• Lua Guide
• Fennel Cheatsheet

Reference

• Elements
• Theme
• Effects
• Dev Server
• Canvas

Specs

• Core API -- frame format, events, host functions, dev server
• App API -- dataflow, effects, view runner