Show HN: Klad, a paint app your coding agent can drive (source-available)

klad Give your agent real brushes. klad is a 2D painting and animation app you share with a coding agent. You paint in the editor with a pen. The agent paints through the klad command line, with the same brushes, on the same drawing, and each of you sees the other's strokes instantly. There is no image model in klad. Your agent (Claude Code, Codex, anything that can run commands) decides what to paint; klad gives it brushes, layers and a timeline. Whatever either of you puts down stays what it was: a stroke with its path, pressure, brush and colour, a shape with its points, a fill with its region. So there's no rerolling and hoping for the best: if one leaf looks off, you fix that leaf. Asked for "a little sprout creature for my game", the agent paints 4,344 strokes and fills. You change them: recolour the leaves, bend the mouth, move a smudge, blend the blush. Then the agent animates it: the creature's parts go into five groups, 205 keys move them, and no frame is painted again. Drawings made with Claude Fable 5.2: the creature, the scene and the prop kit were painted stroke by stroke through the klad command line. Site and guides: klad.studio , with these drawings replayed stroke by stroke. Licence: source-available, not open source. Free to build and use for yourself, and inside a company with less than 500,000 euros a year in revenue. See Licence . Runs on: macOS (pen pressure and tilt). It also builds and passes its tests on Linux and Windows, checked on every change; the editor starts on Linux with the mouse for now, and nobody has drawn with it on Windows yet. Status: early. This is the first public version, and you build it yourself: see From source . Why not just generate the picture? An image generator hands you pixels, and the only edit left is another roll of the dice. klad keeps every stroke and every fill as data: where it went, how hard it was pressed, its brush and its colour. Pick any of them hours later, yours or the agent's, and recolour it, bend it, move it or delete it. It's paint, not just vectors. A stroke keeps its path and pressure like a vector does, and still lands as paint. Loaded oil leaves ridges that catch the light, and smudge drags the paint already on the layer. The smudge stays a stroke too: move it later and klad blends it again where it lands. It can also do just vectors. Shapes with editable points, gradients, glows and real text in about fifty open fonts that come with it, for posters, covers and cards. It's a full painting and animation app. Two dozen brushes and a brush editor, layers, masks, clipping, effects, a timeline with onion skins and clips, in-betweens made from your key drawings, bones with IK, and exports as PNGs, sprite sheets or straight into Godot. Your drawings stay yours. A drawing is a folder of plain files on your computer, and klad needs no account. It only looks for a new version once a day, and you can turn that off. An edit changes only the files of what it edits, so drawings live well in git. Working with your agent Ask. Tell your agent what the drawing needs, in plain words: a lantern for the inn, lit from the left, on its own layer. Watch. It paints through the klad command line, and its strokes show up in your editor about a second later. Point. Pin a note on the canvas or select the part you mean ("more moss on this side"). The agent reads both. Take over. Repaint whatever you like by hand, the agent's strokes as much as your own. Its strokes are marked as its own and every change is one step in a shared history, so you can undo any of it. The prompt to start with is under Try it . klad skill prints the agent skill in docs/skill/SKILL.md : how to look at a drawing, change it and check the result. A second one, klad skill drawing ( docs/skill/drawing/SKILL.md ), teaches the craft: planning a picture, light on form, values, edges, colour, materials and how to judge the result. Both are MIT, so use them with any agent and any tool. Open the drawing to watch and draw along: What an agent paints depends on the agent and on how much you steer it. The skills teach it the tool and some craft; the pen in your hand does the rest. For developers: the drawing is data Everything you can do in the editor has a klad command too, so a script or an agent works on the same drawing you have open. It reads strokes as JSON, changes any of them by its address and applies batches of edits as JSON ops. To In the editor From a script or an agent Paint B and a pen with pressure klad stroke art.klad l4 --brush oil --path 'M100 400 C 300 200 500 600 700 400' Change a stroke later S to pick it, then recolour, resize or move; A bends its path klad set art.klad c4:s12 size=3.5 color=#3355aa Read what is there Point at it with S klad strokes art.klad l4 --json Flat colour G , filling against the lines layer klad fill art.klad l2 --at 820,640 --ref lines --gap 4 --color skin Point at something N pins a note, S selects klad notes art.klad , klad selection art.klad In-betweens The in-between window klad inbetween art.klad --layers lines,colour --from 0 --to 6 Export cmd E , or export to Godot from a clip klad export art.klad --godot ../game/art Undo cmd Z , or the History pane klad undo art.klad The file format is documented down to the byte under the MIT licence ( docs/format.md ), so other apps and engines can read and write klad drawings with or without klad. Made for games Props, characters, backgrounds and frame-by-frame animation. Draw the key poses and klad makes the drawings in between, part by part; it checks the arcs (a foot that slides, a part that sinks under the ground), colours every drawing from the first one, and exports sprite sheets or a Godot SpriteFrames scene with each clip's timing. klad inbetween creature.klad --layers lines,colour --from 3 --to 5 --spacing in-out klad arcs creature.klad --track ' lines:near leg ' --clip walk --check klad export creature.klad --godot ../game/art Try it git clone https://github.com/klad-app/klad && cd klad just compile # about ten minutes the first time target/release/klad open # on Linux: target/linux/release/klad open Then let your agent paint Put klad on your path, for you and for your agent: target/release/klad install (on Linux target/linux/release/klad install ; on a Mac it may ask for your password). Start your coding agent (Claude Code, Codex, or anything else that can run commands) in the folder where the drawing should go, and paste: Run klad skill and klad skill drawing and read what they print. Then make scene.klad and paint a night scene: a hooded traveller holding a lantern out to a ruined arch, a small creature following, flat shaded and lit by the lantern. Once it has made scene.klad , open it in another terminal to watch the strokes land, and draw along: klad open scene.klad . Then steer it. Press N to pin a note on the canvas ("more moss on this side") and tell the agent to read your notes, or pick any stroke with S and change it yourself. Every build holds the klad command line tool, the editor, the fonts, the licences, the agent skill and six sample drawings to look at and draw on (the start window shows them; klad samples lists them and copies one out). The first start offers first steps: draw a shape, fill it and hand the drawing to an agent. The guides in docs/guide/ show how to paint, select, fill, animate, rig and export in the editor, one recipe at a time, starting with Getting started . From source Building takes about ten minutes the first time. Install Rust with rustup and just ( brew install just , or cargo install just ). On Linux also pkg-config , libfreetype-dev , libfontconfig1-dev , libxkbcommon-dev and libwayland-dev . git clone https://github.com/klad-app/klad && cd klad , then just compile makes klad and klad-editor for the machine you ar