Modern, open-source ECU tuning software for Speeduino, rusEFI, epicEFI, and other INI-compatible aftermarket engine control units. Built with a Rust core and a native desktop UI via Tauri.
⚠️ Pre-release software. LibreTune is under active development and has not shipped a stable release yet. The nightly build is the recommended way to run it — it is rebuilt whenever there are new commits and published only after the full test suite passes. Expect rough edges, and keep backups of your tunes. Contributions are welcome — see CONTRIBUTING.md and the CHANGELOG for what's landed recently.
Download the latest nightly build — no compilation required:
| Platform | Download | How to run |
|---|---|---|
| Linux | AppImage (recommended; .deb and .rpm also available) |
chmod +x LibreTune-nightly-*.AppImage, then run it — no install needed |
| Windows | Portable EXE |
Download and run — no installer needed |
| macOS | aarch64 DMG for Apple Silicon (M1+), x64 DMG for Intel — not universal |
Drag LibreTune to Applications, then see the first-run note below |
First-run notes
- macOS: builds are ad-hoc signed but not notarized, so macOS may report the app as damaged or from an unidentified developer. Open System Settings → Privacy & Security and click Open Anyway, or run:
xattr -dr com.apple.quarantine /Applications/LibreTune.app - Windows: the EXE is unsigned, so SmartScreen may warn on first launch — click More info → Run anyway.
- Linux (AppImage): if it will not launch, make sure it is executable and that FUSE is available (most desktop distros ship it).
Starting from a blank tune? Describe your engine — cylinders, displacement, injector size, fuel type, aspiration — and LibreTune generates a conservative, driveable starting tune: VE, ignition, and AFR tables plus cranking and warmup enrichment curves. Available from the new-project flow or Tools → Generate Base Map; individual tables can also be regenerated in place via the table editor's Generate… action.
Full-featured 2D grid editor with 3D surface visualization, keyboard navigation, and live ECU cursor tracking. Includes Set Equal, Scale, Interpolate, Smooth, Re-bin, Copy/Paste, table comparison, per-table generation, and direct Burn to ECU.
Import existing .dash files or build layouts from scratch with 13 gauge types (analog dials, bar gauges, sweep gauges, digital readouts, line graphs, histograms, tachometers, and more). Drag-and-drop designer mode with three default dashboards included.
Live fuel table recommendations based on AFR targets with heat map visualization, cell locking, authority limits, transient filtering, lambda delay compensation (fixed, flow-scaled, or measured via the built-in AFR Delay Test), and fuel-cut / railed-sensor exclusion.
Data logger with configurable sample rates, playback controls, CSV import/export, math channels, and alert rules. Tooth logger and composite logger for trigger pattern analysis. Text-based ECU console for rusEFI/FOME/epicEFI.
Project-based workflow with restore points, Git-based tune versioning, CSV export/import, TunerStudio-compatible per-table .table import/export, TunerStudio project import, INI version tracking with automatic tune migration, and change annotations. Online INI search from Speeduino, rusEFI, and FOME GitHub repos, offered automatically on ECU signature mismatch.
- AI Assistant: Bring-your-own-LLM co-pilot (OpenAI / Anthropic / Google / local Ollama or LM Studio, with one-click presets) that reads your tables, realtime data, and datalogs, diagnoses problems, and proposes validated, authority-clamped changes for explicit review — applied only after your approval (restore point first) and never burned automatically. OS-keychain API-key storage, capability tiers, pin-conflict warnings, and an "Ask AI" button on every table editor.
- MCP Server (local, read-only): expose the same tune-inspection tools to external agents (Claude Code, Claude Desktop, any MCP client) over a loopback HTTP server with bearer auth. Off by default; no tool can edit a tune or touch the ECU.
- Multi-monitor: Pop out any tab to its own window with bidirectional sync
- Unit preferences: Temperature (°C/°F/K), pressure (kPa/PSI/bar/inHg), AFR/Lambda
- Performance calculator: Estimated HP/torque curves and acceleration times
- Action scripting: Record and replay tuning actions across tunes, with INI-backed validation
- Lua scripting: Sandboxed Lua 5.4 engine for custom calculations, automated test sequences, and advanced data processing (Tools → ECU Lua Editor)
- Extensible: WASM plugin system with sandboxing and permission model
- Localization: i18n scaffold with English, Brazilian Portuguese (
pt-BR), and Hungarian (hu-HU); add new locales undercrates/libretune-app/src/i18n/locales/ - Demo mode: Run the app without an ECU using the bundled simulator (Settings → Enable Demo Mode)
For full documentation, open the in-app manual (Help → User Manual — bundled with every build, no internet needed) or read the architecture overview.
| Welcome Screen | Settings Dialog | Dashboard |
|---|---|---|
 |
 |
 |
| AutoTune | ECU Settings | VE Table |
|---|---|---|
 |
 |
|
| ECU | INI Support | Serial Protocol |
|---|---|---|
| Speeduino | ✅ | ✅ |
| rusEFI | ✅ | ✅ |
| FOME | ✅ | ✅ |
| epicEFI | ✅ | ✅ |
| MegaSquirt MS2/MS3 | ✅ | Partial |
Any ECU using the standard INI definition format should be compatible.
Prefer to compile it yourself? The same procedure works on Windows, macOS, and Linux.
Show build instructions
You will need Rust (stable) via rustup, Node.js 20+, and your platform's build dependencies — WebKitGTK packages on Linux, Visual Studio Build Tools on Windows, or the Xcode command-line tools on macOS. The exact lists are in CONTRIBUTING.md:
git clone https://github.com/RallyPat/LibreTune.git
cd LibreTune/crates/libretune-app
npm install
npm run tauri devFor an optimized release build, run npm run tauri build instead.
libretune/
├── crates/
│ ├── libretune-core/ # Core Rust library
│ │ └── src/
│ │ ├── ini/ # INI file parsing
│ │ ├── protocol/ # Serial communication
│ │ ├── ecu/ # ECU memory model
│ │ ├── datalog/ # Data logging
│ │ ├── autotune/ # AutoTune algorithms
│ │ ├── tune/ # Tune file management
│ │ ├── dash/ # Dashboard format (incl. layout.rs defaults)
│ │ ├── agent/ # AI assistant orchestrator, tools, safety tiers
│ │ ├── llm/ # LLM provider trait + OpenAI/Anthropic/Google impls
│ │ └── project/ # Project, restore points, Git versioning
│ └── libretune-app/ # Tauri desktop application
│ ├── src/ # React frontend (TypeScript)
│ │ ├── components/ # UI (dialogs, dashboards, gauges, tuner-ui, …)
│ │ ├── contexts/ # Cross-cutting React providers
│ │ ├── hooks/ # Reusable hooks (realtime, ECU events, …)
│ │ ├── i18n/ # Localization (en, hu-HU, pt-BR)
│ │ └── stores/ # State stores
│ └── src-tauri/ # Tauri backend (Rust)
│ └── src/
│ ├── commands/ # Tauri commands (~80 topic modules)
│ └── state.rs # Shared AppState
├── docs/ # User manual (mdBook) + architecture.md
├── scripts/ # Build and development scripts
├── CHANGELOG.md # Keep-a-Changelog history
└── Cargo.toml # Workspace root
For a deeper dive into module boundaries and Phase 1–8 cleanup history, see docs/architecture.md and CHANGELOG.md.
See CONTRIBUTING.md for development setup and guidelines, and docs/architecture.md for a tour of the codebase.
# Rust workspace
cargo test --workspace
# Frontend (vitest)
cd crates/libretune-app && npm run test:runcargo clippy --workspace --all-targets -- -D warnings
cargo fmt --all -- --check
cd crates/libretune-app
npm run typecheckThe full pre-push pipeline (build + tests + clippy + fmt + frontend build/tests) is wrapped in scripts/pre-push.sh. Both Git hooks are opt-in: scripts/setup-git-hooks.ps1 (or .sh) enables the pre-commit format check, and ./scripts/pre-push.sh --install-hook runs the full pipeline before every push.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation.
See LICENSE for the full license text.
Contributions are welcome! Please read CONTRIBUTING.md before submitting PRs.
LibreTune is an independent open-source project and is not affiliated with EFI Analytics.