LightCraft

Your photos. Your pixels. Your machine.

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Photo library and raw development; an open-source, non-destructive photo library and raw developer, built in pure Rust.
Native on macOS, Windows and Linux. In the browser via WebAssembly. Drivable end to end by AI agents over MCP.

LightCraft on getartcraft.com · ArtCraft · All Crafting Apps

_{Ansel Adams, "The Tetons and the Snake River" (1942). Public domain, U.S. National Archives. Developed in LightCraft.}

Note

ArtCraft is a community of artists from all walks of life. Digital, generative, music, games — if you make things, you're one of us. Come say hi on Discord.

Editing · Color grading · Before & after · Masking · Presets · Library · Agents & MCP · Performance · Status · Quick start · Roadmap · Downloads · Crafting Apps

Edit like you mean it

LightCraft is a complete darkroom in a single native app. Every adjustment is non-destructive, so your originals are never touched. Every slider renders through a scene-referred, wide-gamut, 32-bit float pipeline: highlights roll off like film, shadows open up without halos, and colour stays clean from capture to export.

☀️ Light Exposure, Contrast, Highlights, Shadows, Whites, Blacks, with edge-aware local tone mapping (a guided filter on log-luminance). Pulling −100 Highlights recovers a blown sky without the grey halos you'd get from a naive curve. 🎨 Color White balance by temperature and tint (Kelvin for raw, relative for JPEG) with presets, Auto and a click-to-neutralise eyedropper. Vibrance that protects skin tones, Saturation, an 8-band Color Mixer (hue / saturation / luminance) and 3-way Color Grading wheels with blending and balance. All of it is computed in OkLCh, a modern perceptual colour space.

✨ Effects Texture for fine detail, Clarity for mid-tone punch, Dehaze (dark-channel prior with guided refinement; push it negative to add atmosphere), post-crop Vignette with highlight priority, roundness and feather, and resolution-independent film Grain with size and roughness. 📈 Tone Curve Parametric region curve with movable splits plus point curves for RGB, Red, Green and Blue. Curves are monotone by construction, so you never get an accidental tone inversion.

_{A gentle S on the RGB point curve, right under the Light sliders. Ansel Adams, 1942 (public domain).}

Color grading, the cinematic way

Split-tone shadows, midtones and highlights independently with drag-anywhere colour wheels. Below, Dorothea Lange's Migrant Mother gets a warm, print-like tone (highlights at 42°, shadows at 28°) in two drags.

_{Shadows, midtones and highlights wheels in the Color panel. Dorothea Lange, "Migrant Mother" (1936). Public domain, Library of Congress.}

Before & after

Press \ to toggle the Before view, Y for side by side, or Shift+Y for a split view. Every image below is a real screenshot of LightCraft, captured automatically by an agent through the control channel.

The Tetons and the Snake River. Highlights −45, Shadows +38, Clarity +28, Dehaze +18. Ansel Adams, 1942 (public domain).	Migrant Mother. Shadows +42, Texture +18, split-toned grade, vignette. Dorothea Lange, 1936 (public domain).
Earthrise. Dehaze +22, Highlights −30, warmer white balance, Vibrance +22. NASA / Bill Anders, Apollo 8, 1968 (public domain).	The Blue Marble. Highlights −38, Blacks −20, Dehaze +15, Vibrance +30. NASA, Apollo 17, 1972 (public domain).

Masking that goes where you point

Paint with a Brush (size, feather, flow, density, erase), drop Linear and Radial Gradients with draggable pins, or select by Luminance Range, Color Range, Sky, Subject and Background. Combine components with Add / Subtract / Intersect, invert any of them, and dial in 17 local adjustments per mask (Temp, Tint, Exposure, Contrast, Highlights, Shadows, Whites, Blacks, Texture, Clarity, Dehaze, Hue, Saturation, Sharpness, Noise, Moiré, Defringe), plus an overall Amount.

Desktop Object and Describe masks use SAM 3 for click-based and text-prompt selection, with a separately installed model; see model setup and terms. Subject, Sky and Background selections still use classical heuristics. Existing model-generated masks render and export without the model installed.

_{A radial "Sun glow" mask (Temp +40, Exposure +0.50) layered over a linear "Sky" mask. Photo from LightCraft's procedurally generated demo library.}

Presets, profiles & the Color Mixer

Forty-one hand-built presets ship in the box (Golden Hour, Teal & Orange, Faded Matte, Selenium Tone, Crisp Landscape and more), each with an Amount slider from 0 to 200 %. Save your own from any group of settings, mark favourites, and copy, paste or sync edits across a whole selection with exactly the groups you choose.

_{The Presets column next to the 8-band Color Mixer. Photo from the demo library.}

✂️ Crop, straighten & geometry Free or locked aspect ratios (1:1, 4:5, 5:7, 2:3, 4:3, 16:9, 16:10, original), drag-to-rotate straightening that always keeps the largest crop inside the image, thirds / grid / golden-ratio overlays, flips and 90° rotations, plus manual Vertical, Horizontal, Rotate, Aspect, Scale and Offset transforms.	⚫️ Black & White One click (V) to monochrome, with an 8-band B&W Mix that lets you darken skies or make foliage glow. Then tone it with Color Grading for selenium, sepia or split-tone prints.
A 16:9 crop straightened +2.5° with the thirds overlay. Ansel Adams, 1942 (public domain).	Split view: colour original on the left, B&W with Clarity, Vignette and Grain on the right. Demo library.

Organize everything

A library that stays out of your way: All Photos, Recently Added, Picks, By Date, Albums nested in Folders, and Recently Deleted. Rate with 0–5, flag with P / X / U, colour-label with 6–9. Search understands fields: rating:>3 flag:pick iso:>800 camera:x2 date:2026-04 keyword:mountains person:"Jane Doe"; plain words also match the people named on faces, and quotes keep several words together. Every view sorts by capture date, import date, edit date, name, rating, size or at random (a stable shuffle; View → Sort → Reshuffle for a new one). The justified Photo Grid and Square Grid views are virtualized, so they stay smooth whether you have forty photos or forty thousand.

The People view groups named faces, including names read from XMP; face boxes can be edited in the loupe. On desktop, automatic detection and recognition use optional models installed through Settings → Faces; no weights are bundled. See face models and setup.

Photo Grid with albums nested in a folder, ratings and flags. Demo library.	Square Grid of the four public-domain showcase photos.
The Info panel: file, dimensions, rating, title, caption, copyright and camera metadata. NASA / Bill Anders, "Earthrise", Apollo 8, 1968 (public domain).

Built for agents

Every menu item, slider, brush stroke, crop handle and keystroke in LightCraft is a command with a stable id and JSON parameters. The UI, the keyboard, the CLI, a JSON-lines control channel and an MCP server all dispatch through the same entry point. An agent can cull a shoot, develop it, mask a sky and export it, and see the result.

lightcraft --control 7980 ~/Pictures/trip

{"method": "engine.execute", "params": {"command": "photo.flag",  "params": {"flag": "pick"}}}
{"method": "engine.execute", "params": {"command": "develop.set", "params": {"values": {"light.highlights": -45, "light.shadows": 38}}}}
{"method": "engine.execute", "params": {"command": "mask.add",    "params": {"kind": "radial", "center": [0.62, 0.4], "rx": 0.2, "ry": 0.14}}}
{"method": "ui.clickWidget",   "params": {"id": "slider:effects.clarity"}}       // drive any widget by name
{"method": "ui.pointer",       "params": {"events": [{"kind":"down","x":0.2,"y":0.3}, {"kind":"up","x":0.4,"y":0.3}]}}
{"method": "ui.screenshot",    "params": {"path": "after.png"}}

• Command registry. engine.commands lists the available commands; develop.controls lists every slider's range, default and current value.

• MCP server. lightcraft-cli mcp exposes the command registry to Claude (or any MCP client), alongside helpers for import, query, develop, render (returned as an image) and export. Masks have no helper of their own: create and edit them through run_command (e.g. mask.add). It runs headless, or attached to the running app with screenshots, clicks and gestures. See docs/mcp.md.

  cargo build --release -p lightcraft-cli
  claude mcp add lightcraft -- "$PWD/target/release/lightcraft-cli" mcp ~/Pictures/shoot          # headless
  claude mcp add lightcraft-app -- "$PWD/target/release/lightcraft-cli" mcp --connect 127.0.0.1:7980  # live app
  

• Scriptable CLI: lightcraft-cli run --import in.dng develop.set control=light.exposure value=0.7 app.export path=out.jpg longEdge=2048 runs any chain of commands (headless, on a saved library, or against the running app) and prints one JSON result per command; lightcraft-cli render in.dng -o out.jpg --set light.exposure=0.7 --preset ….

• Undo for everything, including agent actions: a slider drag (or a scripted burst of updates) is one undo step.

• Contact sheets (native app / CLI): select photos, then File → Contact Sheet PDF…. Choose A4 or Letter, landscape, rows/columns and filename captions; save a paginated PDF and print it from your PDF viewer. Exports use the current edits, fit each photo without further cropping, and render at 150 dpi in sRGB. The background export supports cancellation and protects originals and XMP sidecars. From the CLI:

  lightcraft-cli run --import ~/Pictures/shoot library.selectAll export.contactSheet path=Contact.pdf paper=a4 columns=3 rows=4 captions=true
  

  export.contactSheet also accepts explicit ids, landscape=true, and paper=letter. It replaces an existing output only after the entire PDF succeeds. Limits: 1,000 photos, 100 pages, 256 MiB; captions are rasterized with the same font coverage as watermarks (CJK requires craft-fonts), with long names shortened in the middle. This is a contact-sheet workflow, not a printer-driver or custom picture-package layout editor.

• Print layouts (native app / CLI): File → Print… opens the Print module's layout editor: Single Image, Contact Sheet, Picture Package (Auto Layout packs cells onto pages) and Custom Package (drag and resize cells, stacking order, snap to cells or a grid), Zoom to Fill / Rotate to Fit, Photo Border and Inner Stroke, paper sizes from 4 × 6 to 13 × 19 and A3 to A5 or custom, margins, rulers in in/cm/mm/pt, page background, 72–720 ppi, and saved templates. Print to PDF… renders in the background. Everything is a print.* command (print.get, print.set, print.cell.add, print.layout.autoLayout, print.exportPdf, print.template.save…), so the CLI and MCP drive it too:

  lightcraft-cli run --import ~/Pictures/shoot print.set 'layout={"style":"picturePackage","page":{"paper":"8x10"}}' \
      print.cell.add width=5 height=7 print.cell.add width=2.5 height=3.5 print.layout.autoLayout print.exportPdf path=Package.pdf
  

  The Print Job panel supports printer/paper ICC profiles, rendering intent, black point compensation, print adjustment, sharpening and 8/16-bit PDF output. Direct printing through an OS print dialog and page overlays (identity plate, watermark, page numbers) are not there yet.

• Slideshows: View → Slideshow plays the photos in view full screen, with fades, repeat and random order. Settings → Slideshow configures layouts, templates, backgrounds, overlays and title screens. Native exports support PDF, JPEG sequences and AV1 video in MP4 or WebM; music and a dedicated Slideshow module editor remain missing. See docs/slideshow.md.

• Every widget is addressable (ui.widgets) and clickable by name, so agents operate the real UI, not a side door.

• The screenshots in this README were produced end to end by the docs/showcase/ scripts. Protocol reference: docs/control-protocol.md.

Fast, native, private

• Pure Rust, no C. Our own RAW decoders (DNG, Canon CR2/CR3, Sony ARW, Nikon NEF, Fujifilm RAF incl. X-Trans, Panasonic RW2 / Leica RWL, Pentax PEF, Olympus ORF), our own colour science, our own pipeline. JPEG, PNG, TIFF, WebP, PSD composites, JPEG XL, GIF (first frame) and BMP open today; HEIC/HEIF photos too with --features heif (HEVC is a build-time choice, as in PhotoCraft).
• Scene-referred & wide-gamut. Linear Rec.2020 float internally, Bradford-adapted white balance, gamut mapping instead of clipping, a filmic shoulder for raw and pixel-exact pass-through for JPEGs you haven't touched.
• Resolution-independent edits. Radii and brush sizes are relative to the image, so a 400 px preview, your 5K display and a 60 MP export look the same.
• GPU-accelerated, CPU-exact. The whole develop pipeline runs as wgpu compute kernels (Metal / Vulkan / DX12), checked against the CPU pipeline to within 1/255. On a 24 MP raw (Apple M4 Pro): a slider update re-renders in ~4 ms, a cold 2.5 MP loupe in ~30 ms, and a full-size export in ~0.3 s including a parallel JPEG encode. Without a GPU the same pipeline runs on all CPU cores, redoing only the stages a slider affects. Batch exports render several photos side by side, so one's decode and encode overlap another's render.
• Instant culling. Opening a raw shows its embedded camera preview or cached render within ~0.1 s while the full render follows (~0.2–0.5 s for 24 MP). The next and previous photos are prepared in the background, so stepping through a shoot takes ~50 ms per photo.
• Background rendering. A worker pool renders the loupe, before/after and every visible thumbnail off the UI thread: drafts during drags, full quality on release.
• Local-first. No account, no cloud, no telemetry, no subscription. Your catalog is an append-only log of human-readable operations you can diff, back up or replay.

Feature status

LightCraft is young and moving fast: alpha. Where we honestly stand (details in the roadmap and docs/target-app-parity.md):

• By feature count we're at ~82% (core features 98%), tracked row by row in docs/parity-checklist.md.
• As a day-to-day tool we're nearer 61% for the whole product, ~51% for a typical working photographer and ~65% for casual use. It's great for JPEG/DNG and most Sony / Panasonic / Fujifilm / Nikon / older-Canon raws on one machine; see docs/raw-parity.md for your camera.
• The biggest gaps:
  • camera colour calibration: Sony, Nikon, Panasonic, Fujifilm and Canon CR3 and CRW raws have guarded estimates from their camera JPEGs, with built-in Canon EOS D60, ILCA-99M2, ILCE-7CR, ILCE-7M4, ILCE-7RM5, X-H2S, X-T4, Nikon Z 6II, Z 8 and D5300 profiles; measured calibration covers one model so far (chart-measured matrices for the Canon EOS D60), and other raws or rejected fits retain a neutral matrix;
  • compressed Olympus raws and unsupported CR3 variants: these use embedded JPEG previews when present. Fujifilm lossless/lossy compressed RAF now decodes sensor data; verification and existing-library reload instructions;
  • AI quality and model setup: Subject and Sky selection are classical heuristics; Object/Describe use an optional SAM 3 model. AI Denoise supports Bayer RAW with separately installed weights, while X-Trans and linear-RGB denoise and Super Resolution remain missing; see AI masks and AI Denoise;
  • network libraries: a preview reads the raw's header — or, for a CR3 or a TIFF raw whose preview tag sits past it, exactly the ranges the sparse planner names — and its embedded JPEG only (56.5 MB → 5.9 MB, 10 s → 1 s on the test share), but the developed picture still needs the sensor data over the wire; see docs/raw-preview-reads.md;
  • on-screen HDR display, video import/editing, and the Book / Map module views. Print layouts and colour-managed PDF output work; direct printer output and page overlays remain missing. Slideshow playback and export work, with a dedicated module editor and music still missing.
• What's next: see the ranked gaps and the roadmap.

Area	Status
Library: albums, folders, smart albums, stacks (incl. auto-stack), virtual copies, ratings, flags, labels, filter bar, search, sort, grids, filmstrip	✅
Culling: Compare (synced zoom) and Survey views, auto-advance, instant previews	✅
Light, Color, Effects (vignette styles), Tone Curve (+ refine saturation, targeted adjustment), Color Mixer (+ targeted), Point Color, Color Grading, Calibration, B&W	✅
Masking: brush, linear, radial, luminance/colour range, add/subtract/intersect; Object and Describe selections	✅ · Object/Describe require optional SAM 3; Subject/Sky remain heuristic (details)
Crop, straighten tool + auto straighten, flip, rotate, aspect ratios, overlays	✅
Profiles (Color, Neutral, Vivid, Landscape, Portrait, Monochrome: our own looks), presets, versions, history, copy/paste/sync settings	✅
Camera colour: DNG matrices, guarded camera-JPEG look fits and built-in profiles for selected cameras	🚧 measured calibration and per-model coverage remain incomplete (raw parity)
Native macOS menu bar (generated from the command registry), control channel + every widget addressable, headless UI snapshots	✅
RAW: DNG, CR2, CR3 (lossless CRX Bayer and version 0x100/0x200 C-RAW), ARW, NEF (uncompressed + lossless/lossy compressed, incl. lossy after split), Fujifilm RAF (uncompressed + lossless/lossy compressed, Bayer + X-Trans), Panasonic RW2 / Leica RWL / Panasonic RAW (every raw format, DMC-LX1 to DC-S1RM2), Pentax PEF, Olympus ORF (uncompressed, 12.8 bpp), Samsung SRW (uncompressed); embedded previews for every format incl. CR3	🚧 · other CR3 variants, compressed ORF / SRW and Nikon HE NEF decode ⬜ (raw parity)
Detail: sharpening, luminance + colour noise reduction	✅ · AI Denoise 🚧 (Bayer, user-installed weights; setup), Super Resolution ⬜
Remove / Heal / Clone spots (auto source), non-generative Fill, editable spot pins, Visualize Spots, Red Eye and Pet Eye	✅ · Fill uses PatchMatch; no generative fill
Export: JPEG / PNG / TIFF / flat PSD / WebP / AVIF / JPEG XL / raw or rendered DNG / original, sizing, file-size limit, output sharpening, naming templates, batch, metadata policy, text or image watermark	✅
HDR: HDR editing with a headroom limit, SDR rendition, Visualize HDR; gain map JPEG, PQ/HLG AVIF, PQ PNG/JPEG XL and float TIFF export	✅ · HDR display ⬜
Library persistence (crash-safe op log + snapshots, background compaction, failed saves reported), disk thumbnail cache	✅
Import: Add in place / Copy / Move, rename and folder templates, devices, duplicate detection, watched folders; Local folder browsing	✅
MCP server (headless or live app, persistent libraries), CLI, control channel	✅
XMP sidecars (read/write, auto-write), reading crs: develop settings, preset files (.lcpreset, XMP presets)	✅
Optics (distortion, vignetting, auto + manual CA, defringe, lens corrections embedded in DNG files, Panasonic / Leica RW2 / RWL distortion data and Nikon Z 6II / Z 8 / Z f distortion data), Geometry (transforms, Constrain Crop), Upright (Auto/Level/Vertical/Full/Guided)	✅ · camera lens profiles (our own) ⬜
Photo Merge: HDR (auto-align, deghost), Panorama (spherical/cylindrical/perspective, boundary warp, auto crop), HDR Panorama → DNG	✅
GPU pipeline (wgpu compute, CPU-exact within 1/255), CPU fallback on device limits / errors	✅ · WebGPU in the browser 🚧
People view, XMP face names and editable face boxes; automatic face detection and recognition	✅ · detection/recognition require optional models (setup)
GPX tracklog auto-tagging and offline reverse geocoding	✅ · place names require the GeoNames dataset; Map view ⬜
Print layouts, picture packages, templates and colour-managed PDF export	✅ layouts/PDF · 🚧 direct printer output and page overlays
Slideshow playback, layouts, overlays, templates and PDF/JPEG/AV1 export	✅ playback · 🚧 dedicated module editor and music (details)
Video import/editing and Book module	⬜
Web build (same UI in the browser via WASM): persistent library in OPFS/IndexedDB, Web Worker rendering, export downloads	✅ · WebGPU, Safari/Firefox testing 🚧

_{✅ works today · 🚧 in progress · ⬜ not started}

Quick start

Workspace builds, including the desktop, web and CLI applications, require Rust 1.95 or newer.

git clone https://github.com/storytold/lightcraft && cd lightcraft
cargo run --release -p lightcraft                       # opens your library (~/Pictures/LightCraft Library; a new one starts with demo photos)
cargo run --release -p lightcraft -- ~/Pictures/trip    # import your photos (folders are scanned, duplicates skipped)
cargo run --release -p lightcraft -- --memory           # a throwaway in-memory demo session (writes nothing)
cargo run --release -p lightcraft -- --control 7980     # with the automation channel
cargo xtask web --serve                                 # the same app in the browser: http://127.0.0.1:8080/
cargo run --release -p lightcraft-cli -- render photo.jpg -o out.jpg --set light.exposure=0.5
cargo xtask ci                                          # fmt, clippy, HEIF, tests, parity, layers, assets, WASM
cargo xtask ci --quick                                  # only what your branch's changes can break (minutes)

cargo xtask ci --quick compares with the merge base of origin/main (--base REF for another) and runs fmt, clippy, the tests of the changed packages, layers and assets, plus HEIF, parity and the wasm check when the changes touch them; a change to Cargo.toml, Cargo.lock or the lint config tests everything. GitHub runs the full cargo xtask ci on every pull request (.github/workflows/ci.yml). Only one ci runs at a time per machine: a second one, from another worktree say, waits for the first and names it, since several at once take longer in total than in turn. LIGHTCRAFT_CI_SLOTS=2 allows two; LIGHTCRAFT_CI_LOCK=off skips the lock.

CI defaults to line-table debug information and one build job per 1.5 GB of RAM available when it starts (at most one per CPU; 4 if memory can't be read), so an 8 GB machine with 6 GB free builds with 4, and a busy machine with little free builds with fewer. Test threads follow, capped at 4. Full-debuginfo linkers, one per CPU, otherwise exhaust RAM before any test runs. GPU coverage is unchanged. Explicit CARGO_PROFILE_DEV_DEBUG, CARGO_BUILD_JOBS, RUST_TEST_THREADS and NEXTEST_TEST_THREADS settings override these defaults. The tests run under cargo test; LIGHTCRAFT_NEXTEST=1 runs them under cargo-nextest instead (one process per test, slower here because each regenerates the demo scenes). Ordinary development commands keep their own settings.

Release builds on memory-constrained machines: #1196 reports Arch/AUR release-link OOM kills on a 16 GB machine when the desktop and CLI build concurrently with full debug information, thin LTO and one codegen unit. The CI defaults above do not apply to ordinary cargo build --release. Start with one job; two may be suitable if enough memory is available:

CARGO_BUILD_JOBS=1 cargo build --release -p lightcraft -p lightcraft-cli
# Alternatively: CARGO_BUILD_JOBS=2 cargo build --release -p lightcraft -p lightcraft-cli

If a packaging environment enables full debug information or memory-heavy LTO settings, use command-local overrides for a lower-memory source build:

CARGO_BUILD_JOBS=1 CARGO_PROFILE_RELEASE_DEBUG=0 CARGO_PROFILE_RELEASE_LTO=false CARGO_PROFILE_RELEASE_CODEGEN_UNITS=16 cargo build --release -p lightcraft -p lightcraft-cli

These POSIX-shell assignments affect only this command, not global Cargo configuration or the repository's release profiles. Disabling LTO may change performance and binary size; disabling debug information reduces debugging detail. This is build guidance, not a guarantee that any machine has enough memory. Downstream packagers should serialize large binary builds and avoid full debug information combined with LTO and one codegen unit on low-memory builders. A PKGBUILD that exports its own profile settings can override inherited variables; adjust the packaging recipe locally or contact its maintainer rather than assuming an environment prefix on makepkg will take precedence.

Linux/Arch build troubleshooting: rustc SIGILL with ThinLTO. In #2811, an Arch Linux x86_64 build on an AMD Ryzen 9 7900X3D with 64 GB RAM failed with rustc 1.99.0 / LLVM 23.1.1, AUR lightcraft 0.7.1-1 and 0.13.0-1, RUSTFLAGS="-C opt-level=3 -C target-cpu=native", and release settings opt-level=3, lto=thin, codegen-units=1. cargo build --frozen --release reached the executable crates before rustc crashed with signal 4 (SIGILL / ILL_ILLOPN). The core dumps point into LLVM's SelectionDAG / vector-combine optimization path; the exact compiler root cause has not been isolated. This does not mean every machine with that hardware or toolchain will fail. It is a different observed failure from the 16 GB OOM kills in #1196 above; there is no evidence establishing a shared root cause.

For a direct Cargo source build, the equivalent command-local LTO override is:

CARGO_PROFILE_RELEASE_LTO=off cargo build --frozen --release

Reporter @rwarmstr verified the workaround by exporting CARGO_PROFILE_RELEASE_LTO=off inside the AUR PKGBUILD's _srcenv() function and rebuilding both package versions, without changing RUSTFLAGS. The reporter tested the AUR recipe, not the direct Cargo invocation above. A variable prefixed to makepkg alone may be overwritten by the PKGBUILD's own exports; the recipe must honor or set the override. The AUR !lto opt-out behavior is tracked separately in #2813.

Cargo's LTO documentation distinguishes false from off: false can still perform thin local LTO across codegen units (unless codegen-units=1 or opt-level=0); off disables LTO explicitly. The low-memory recipe above is unchanged. This workaround is for affected builds, not a new default; disabling LTO may change performance, binary size and build behavior.

Tests that need a GPU, the corpus, the craft-fonts faces or a model pass without checking anything when those are missing (libtest has no "skipped" status), so cargo xtask ci lists them: tests record a skip with lightcraft_testkit::skip!, and the run ends with what the machine offered (OS, CPUs, RAM, GPU adapters per backend, corpus, fonts) and every skip by reason. It writes target/ci/report.json and target/ci/summary.md, a block to paste into a PR (--summary-md prints it); --hardware also runs the GPU tests on every backend that has a hardware adapter. Nothing is uploaded.

Chinese and Japanese text need the shared font repo, an optional build input (official releases always include it):

git clone https://github.com/storytold/craft-fonts ../craft-fonts
CRAFT_FONTS_DIR=../craft-fonts cargo run --release -p lightcraft

Without it LightCraft builds and runs the same, but Chinese and Japanese text have no glyphs. Fonts are never committed to this repo — what goes there is described in the craft-fonts README.

Interface language: Edit → Language (English, 简体中文, 繁體中文（台灣）, 日本語, Português (Brasil), Español, Deutsch, Русский, Français, Українська, Polski, Čeština, Italiano, ქართული, Svenska, Suomi, Bahasa Indonesia, Tiếng Việt) or Settings → General → Language; the choice applies immediately and persists. See docs/localization.md.

Logs: the desktop app writes its log to standard error and to logs/lightcraft.log in its settings folder (Linux $XDG_CONFIG_HOME/lightcraft/logs/, by default ~/.config/lightcraft/logs/; macOS ~/Library/Application Support/LightCraft/logs/; Windows %APPDATA%\LightCraft\logs\), never in the library. Portable mode: a file named portable.txt (or LightCraft.portable) next to the executable moves the settings folder to LightCraftData beside it. A launch from a desktop menu or the Dock has no terminal, so attach this file to a bug report (Help ▸ Open Log Folder shows it in the file manager). Each start moves the previous log to lightcraft.1.log and that one to lightcraft.2.log, so the log of a run that crashed survives the next start; the file stops growing at 16 MiB, --version and --help write none, and runs with LIGHTCRAFT_NO_PREFS log to standard error only. By default LightCraft's own crates log at info and everything else at warn. LIGHTCRAFT_LOG=info or debug works as before (that level for LightCraft's own crates, warnings and errors from the rest; any other value: warnings and errors only) and wins over RUST_LOG, which otherwise replaces the default with env_logger-style directives such as RUST_LOG=debug or RUST_LOG=warn,lightcraft_pipeline=trace (a directive ending in * covers every target starting with it, as in lightcraft*=debug). Panics are recorded there too, and still in lightcraft-panics.log in the temp folder. The logger is apps/lightcraft/src/logging.rs.

The web build needs the wasm32-unknown-unknown target and the matching wasm-bindgen CLI (cargo xtask web prints the exact install command); see docs/web.md.

Nix builds the desktop app and lightcraft-cli (the Nix build always includes the craft-fonts input, so Japanese text has glyphs):

nix run github:storytold/lightcraft                    # the desktop app
nix build github:storytold/lightcraft                  # → ./result/bin/{lightcraft,lightcraft-cli}
nix develop github:storytold/lightcraft                # rust toolchain + native deps + fonts

On NixOS, run a cargo build from nix develop: outside it the app can't find libvulkan.so.1, finds no GPU and renders on the CPU, much more slowly (it says so once at start-up). nix run and nix build set the path themselves.

In a flake configuration (NixOS, home-manager, nix-darwin):

# flake.nix
inputs.lightcraft.url = "github:storytold/lightcraft";
# optional: build against your own nixpkgs instead of the one LightCraft pins
# inputs.lightcraft.inputs.nixpkgs.follows = "nixpkgs";

# then, in a NixOS or home-manager module (where `inputs` is in scope):
nixpkgs.overlays = [ inputs.lightcraft.overlays.default ];   # makes `pkgs.lightcraft` available
environment.systemPackages = [ pkgs.lightcraft ];           # home-manager: home.packages = [ pkgs.lightcraft ];

nix build installs the same desktop file, hicolor icons and AppStream metadata as the .deb/.rpm, and runs cargo test --workspace as its check phase (skip it with pkgs.lightcraft.overrideAttrs { doCheck = false; }).

Keyboard: G grid · D detail · E edit · C crop · M masking · Shift+P presets · \ original · Y before/after · Z zoom · J clipping · ⌘Z undo · ⌘/ all shortcuts.

How it's built

An engine-first Cargo workspace of small, tested crates with enforced layering (cargo xtask layers): geom, color, raster, tiff → raw, codecs, meta, develop → pipeline → catalog → engine → ui-egui. The egui frontend is one swappable crate; nothing below it knows a UI exists. mcp and the apps (lightcraft, lightcraft-cli) sit on top of engine.

Contributing

Humans and agents follow the same rules, so read AGENTS.md first. The short version:

• Clean-room. Never read proprietary binaries or GPL raw/photo code (darktable, RawTherapee, LibRaw, rawspeed, dcraw…); work from public specs and black-box observation.
• No proprietary assets, ever: no icons, screenshots, presets, profiles, LUTs or fonts from commercial products. Every image, icon and font in the repo is original, public domain, Creative Commons, OFL or permissively licensed, and has an entry in assets/ATTRIBUTION.md added in the same commit. New fonts go to storytold/craft-fonts, not here.
• Pure Rust, enforced crate layering, everything is a command, and cargo xtask ci green before every commit (one task id per commit).
• Never crash. Non-test code returns errors instead of panicking: no unwrap(), expect(), panic! or unsafe, checked indexing on anything derived from input, and a regression test with every crash fix. Details in AGENTS.md.

Questions, ideas or a bug you'd like to talk through first? Bring them to Discord.

Downloads

New to LightCraft? Download it from the LightCraft page on getartcraft.com. That's the easiest way to install it.

Want a specific build or format? On GitHub, the latest release has every build listed below, and all releases has earlier versions and their notes. <ver> in the file names is the version number, and SHA256SUMS.txt lists a checksum for every file.

Windows

Build	Installer	Portable
x64 (64-bit Intel/AMD)	lightcraft-<ver>-windows-x64.msi	lightcraft-<ver>-windows-x64-portable.zip
arm64 (Snapdragon and other ARM PCs)	lightcraft-<ver>-windows-arm64.msi	lightcraft-<ver>-windows-arm64-portable.zip
x86 (32-bit)	lightcraft-<ver>-windows-x86.msi	lightcraft-<ver>-windows-x86-portable.zip

Installers and executables are code-signed. The installer asks who to install for and where (for your account only, in %LOCALAPPDATA%\Programs\ArtCraft\LightCraft, by default; "Everyone on this computer" uses C:\Program Files\ArtCraft\LightCraft (Program Files (x86) for the 32-bit build); upgrades stay in the folder you chose) and ends on a page confirming LightCraft was installed, with an option to start it. For unattended installs: msiexec /i lightcraft-<ver>-windows-x64.msi /qn INSTALLFOLDER="D:\Apps\LightCraft\". A silent install is per-user by default. INSTALLFOLDER chooses the folder, not who it is installed for; add ALLUSERS=1, from an elevated terminal or deployment tool, for an all-users install.

Update or uninstall asks for an old .msi, or stops with error 1612 or 1714? Windows removes the installed version with its own cached copy of that version's installer; if the copy is gone, it asks for the original file and stops (an update then ends with error 1603). Download the release MSI of the version and build you have installed from all releases and run msiexec /fv "<path to that .msi>" /qb+ /norestart, approving the permission prompt if Windows shows one. That restores the cached copy; then retry the update or uninstall. Opening the MSI, or choosing Repair or Uninstall on it, may still fail. Error 1603 has other causes too; if this doesn't help, open an issue with the error message.

macOS

Build	File	Notes
App, universal (Apple silicon + Intel)	lightcraft-<ver>-macos-universal.dmg	Signed and notarized
Command-line tool, universal	lightcraft-cli-<ver>-macos-universal.zip	Signed and notarized

Linux

Format	x86_64	aarch64 (ARM64)	Notes
AppImage	lightcraft-<ver>-linux-x86_64.AppImage	lightcraft-<ver>-linux-aarch64.AppImage	Portable; updates with AppImageUpdate (.zsync files)
Flatpak	lightcraft-<ver>-linux-x86_64.flatpak	lightcraft-<ver>-linux-aarch64.flatpak	Sandboxed; flatpak install --user <file>
Debian/Ubuntu	lightcraft-<ver>-linux-x86_64.deb	lightcraft-<ver>-linux-aarch64.deb
Fedora/RHEL/openSUSE	lightcraft-<ver>-linux-x86_64.rpm	lightcraft-<ver>-linux-aarch64.rpm
Tarball	lightcraft-<ver>-linux-x86_64.tar.gz	lightcraft-<ver>-linux-aarch64.tar.gz	Unpack anywhere

RISC-V (riscv64): lightcraft-<ver>-linux-riscv64.tar.gz, a tarball only (glibc 2.39 or newer, e.g. Ubuntu 24.04+).

On a Wayland desktop LightCraft runs through XWayland when it is available, because only X11 gives windows file drag-and-drop; set LIGHTCRAFT_WAYLAND=1 to use native Wayland (sharper fractional scaling, no drop).

FreeBSD

Build	File
x86_64	lightcraft-<ver>-freebsd-x86_64.tar.gz

Web (WebAssembly)

Build	File	Notes
Static site	lightcraft-web-<ver>.zip	Runs in a modern browser; host it on any static server

The Crafting Apps

LightCraft is one of the Crafting Apps: free, open-source creative tools from the ArtCraft team, each written from scratch in Rust and each able to stand on its own.

	App	What it's for	Code	Learn more
	PhotoCraft	Image editing: layers, masks, type and real PSD files	GitHub	Website
	VectorCraft	Vector illustration	GitHub	Website
	FilmCraft	Video editing, color and sound	GitHub	Website
	LightCraft	Photo library and raw development	GitHub	Website
	PdfCraft	Reading, organizing and protecting PDFs	GitHub	Website
	EffectCraft	Motion graphics and visual effects	GitHub	Website
	DesignCraft	Page layout and publishing	GitHub	Website
	FigCraft	Interface design and prototyping	GitHub	Website
	WordCraft	Word processing and documents	GitHub	Website
	SoundCraft	Audio recording and editing	GitHub	Website
	DeckCraft	Presentations and slide decks	GitHub	Website
	CADCraft	Computer-aided design	GitHub	Website
	GridCraft	Spreadsheets and data	GitHub	Website
	TextureCraft	3D texture painting	GitHub	Website
	Craft Anything	See how any software works, then build your own	GitHub	Website
	SolidCraft	Parametric 3D CAD by Tangency Labs (community app)	GitHub

And ArtCraft itself, our AI image and video studio for artists who want real control.

Come make things with us

Our Discord is where artists of every kind hang out: people who paint, shoot, draw, cut film, set type, and people still figuring out what they like to make. Share what you're working on, ask for help, tell us what's broken, or tell us what you wish these tools could do. Whatever your medium and however long you've been at it, you're welcome here.

discord.gg/artcraft · getartcraft.com · The Crafting Apps · LightCraft

License and credits

LightCraft is dual-licensed under MIT or Apache-2.0, at your option. Copyright (c) 2026 ArtCraft Team and the LightCraft contributors. Required notices are in NOTICE.

Bundled fonts, icons, images and other assets keep their own open licenses; each one is listed with its author, source and license in assets/ATTRIBUTION.md.

Showcase photographs are public-domain works, used via Wikimedia Commons: Ansel Adams, The Tetons and the Snake River (1942, U.S. National Archives); Dorothea Lange, Migrant Mother (1936, Library of Congress); Bill Anders / NASA, Earthrise (1968); NASA, The Blue Marble (1972). The demo library is procedurally generated by LightCraft. UI font: Inter (SIL OFL 1.1). Builds made with craft-fonts (all official releases) also embed its Chinese and Japanese fonts (Noto Sans CJK SC, BIZ UDPGothic, BIZ UDMincho, Shippori Mincho; SIL OFL 1.1), listed in its ATTRIBUTION.md. All icons are original.

The ArtCraft name, wordmark and logos in docs/brand/ are trademarks of the ArtCraft Team and are not covered by this license. They may be used only unmodified, and only as part of this repository and LightCraft, under docs/brand/LICENSE-brand.txt. Forks and modified versions must remove them.

_{Made by the ArtCraft team and community.}

Star history

Library, Tools, and Presets panels can be regrouped, split, floated within the app window, closed, and reopened. Tools keeps the current Edit/Crop/Masking mode; the photo view and filmstrip stay together. Drag a panel header to a target edge or another header. Its context menu offers Float panel, Move to group, and Close panel. Existing panel toggles reopen panels at their saved location; Reset Panel Layout restores the app layout. Floating panels remain inside the current app window.