Pixel art, born from code

Let AI write how your pixel art is made.

Tessarune is a Windows app that provides your AI coding agent—such as Claude Code, Codex CLI, or Cursor—with a pixel-art drawing language, a local Studio, and a deterministic renderer. Your agent writes each sprite as a JavaScript program, and Tessarune compiles it into PNG, GIF, and sprite sheets. You keep both the art and the code that builds it.

Buy Tessarune $32.99 Read the code

Windows 11 x64
Version 1.3.0
$32.99 one-time purchase
No API key
No network calls

Made with Tessarune

Every frame here was drawn by code.

These props come from Aurum Nocturne’s asset packs on itch.io. Each item is a program written by an AI coding agent in Tessarune, rendered by the engine, and adjusted after checking the frames. No hand painting, no image model.

Open the gallery → 60 props with their full source →

How it works

Describe it. Your agent writes it. Tessarune draws it.

Describe what you want

Specify the size, perspective, lighting, motion, and variants. Studio helps you assemble the brief, which your agent reads beside the manuals and templates.

The brief, as the first lines of cauldron.js:

cauldron.js · 1–3

// Cauldron over a wood fire — 48x48, top-down 3/4, key light top-left.// Loop: 12 frames @ 10 fps. Bubbles swell and pop, the brew swirls, the sigil pulses, steam drifts, fire flickers.// Variants: brew colour green / violet / blue (ramp swap — no new colours).

Your agent writes the drawing as code

Your coding agent writes a JavaScript file using Tessarune’s drawing commands, then runs the Tessarune CLI to render and verify the frames. There is no API key field: Tessarune never makes network calls to an AI.

cauldron.js · 108–116

function bubbles(g, t) {  const spots = [[-6, 1, 0.0], [3, 2, 0.34], [8, 0, 0.68]];  g.detached("bubbles", () => {    for (const [dx, dy, ph] of spots) {      const p = (t + ph) % 1;      const x = CX + dx, y = MOUTH.cy + dy;      if (p < 0.2) g.pixel(x, y, "brew2");      else if (p < 0.45) { g.rect({ x: [x - 1, x], y: [y - 1, y] }, "brew2", { fill: "brew2" }); g.pixel(x - 1, y - 1, "brew3"); }      else if (p < 0.62) {

03
A deterministic render
The engine runs the code for every frame of the loop to place the pixels. Same code, same settings, identical pixels. Export as PNG, GIF, sprite sheets with JSON, or PNG frame sequences.
4×

Why code

A program is a better master copy than a picture.

Reproducible

The same code, engine version, and settings yield identical pixels. Re-export at a different scale, frame count, or sheet layout without running an AI again or paying per-image generation fees.

No image model in the loop

Pixels are created from shapes, ramps, and rules you can inspect, not from a model trained on other people’s art. The license permits you to sell both the images and the code you produce.

Editable part by part

Every part has a name. Shorten a sleeve, shift a lamp by one pixel, or darken a ramp: you or your agent simply edit those specific lines, leaving everything else as it was.

Chest, four facings — A single chest rotated by its program: four directional facings, each lit from the top left.

Variants and motions from one source

Colour variants swap an entire palette ramp. States like lit, unlit, and ignite are arguments in the same function, so a single correction updates every variant.

Wall torch, soulfire — wall_torch.js: fire, soulfire, witchfire, and the ignite animation.

What’s in the box

The renderer, and everything around it.

Studio

A local studio in your browser. Preview art beside your code as it updates with every file save. Inspect motions, frames, palettes, layers, and notes.

JSON CLI for agents

Create, render, check, and export via CLI commands with JSON output. Your agent drives Tessarune just like your standard build tools.

Deterministic renderer

The pixel-art compiler and runtime. Ships with both runtimes (0.3.0 and 0.4.0), ensuring earlier files continue to render the exact same picture.

25 manuals, Japanese and English

Written for agents to read: drawing APIs, pixel-art rules, motion, 3D rigs, manikin-first characters, and review workflows.

Templates, style profiles, examples

Editable starter files, plus designated places to keep style guidelines, references, and production notes between sessions.

Review and history

Magnified views, frame inspection, value studies, highlighting candidates for flicker or missing pixels, and a full history of accepted versions.

Export for games

Export as PNG, GIF, sprite-sheet PNG with JSON metadata (frame bounds, fps, anchor points), or PNG frame sequences at any integer scale.

Japanese and English

Studio, CLI messages, AI handoffs, and all manuals in both English and Japanese.

Requirements

What you need.

Operating system	Windows 11 x64 only. There is no macOS, Linux, or mobile version.
Your AI agent	A coding agent that can edit local files, execute commands, and inspect images—such as Claude Code, Codex CLI, or Cursor. The agent is not included; its subscription and fees are yours.
Download	A single ZIP archive of approximately 61 MB, containing the Windows Setup, a portable build, and bilingual documentation.
Nothing else to install	The execution runtime is built in. No Node.js, dedicated GPU, or image models required.
Network	Tessarune itself makes no network calls. Studio listens only on 127.0.0.1.
Outputs	PNG, GIF, sprite-sheet PNG with JSON, and PNG frame sequences. No MP4, FBX, or glTF.

About the Windows SmartScreen warning

Because the installer is not code-signed, Windows SmartScreen may display “Windows protected your PC”. If you purchased and downloaded Tessarune from its store page, click More info → Run anyway. The portable edition requires no installation. To verify the download, compare file SHA-256 hashes against these values:

Tessarune-1.3.0-Setup.exe
6883468d611b7b0f9159e6e638093c047f5e054c23e4842c6aa1eabef282c75b

Tessarune-1.3.0-windows-x64.zip
131c5819a815181073fa9807b2b8b17b31460eaf2eb920bfae0aab975769d0a9

Price

One purchase. Yours to keep.

$32.99

USD, one-time purchase · Tessarune 1.3.0

Buy on itch.io Or buy on Gumroad

Your AI coding agent and subscription are not included. Windows 11 x64 only.

Future updates released for this product, including major versions, are included at no additional charge and delivered directly through your purchase store.
No account registration, license key, activation, or expiry.
Sell the images, animations, and code you create. Review the license.
One purchase covers one person across devices they own or manage.

License

The license, in plain words.

The complete end user license agreement is provided in the download in both English and Japanese. The Japanese text is legally authoritative; this summary is for reference only.

One purchase, one person. You may install Tessarune on devices you control. Each additional user must purchase a separate license.
What you make is yours to use and sell. You may use and sell all sprites, animations, videos, and artwork code you produce, including works based on the bundled templates and samples, commercially or not, with no revenue sharing.
The tool itself stays with you. Resale, redistribution, or sharing of the app, engine, or documentation is prohibited. Your AI agent may read the manuals and execute the CLI to help with your own work.
Third-party material is yours to check. Characters, references, and AI service terms you bring into your workflow are subject to their own conditions.

FAQ

Questions before buying.

Do I need an API key?

No. Tessarune has no API key field or AI configuration settings, because it never connects to any external network service. Your AI coding agent runs the Tessarune CLI locally on your computer. Any usage fees depend solely on your agent’s own plan.

Which AI should I use?

Use any coding agent that can edit files, run commands, and inspect images, such as Claude Code, Codex CLI, or Cursor. No model is guaranteed by name. Tiles, effects, and backgrounds usually come out cleanly, while human figures take a few rounds of review and revision. Tessarune provides review, history, and note tools specifically for those iterations. A top-tier model is not required.

Can I use an ordinary chat window?

Usually not directly. Automated workflows require an agent that can access local files and execute the CLI. However, you can still generate drawing code in a regular web chat and paste it manually into Studio.

Is this an automatic AI drawing service?

No. No AI model is bundled. You describe what you need, inspect the rendered frames, and decide on adjustments. A desired visual style or level of polish is not guaranteed in a single attempt.

Will I get the same pixels again?

Yes, provided the code does not rely on system time or unseeded randomness. The exact same source code, seed, settings, and engine version will always produce the same pixels. Note that an AI may write different code if prompted a second time.

Can I sell what I make?

Yes. The license permits the commercial use, modification, publication, and sale of any sprites, animations, video, and artwork code you create, including assets derived from the included templates and examples, with zero revenue share. You may not redistribute the Tessarune application, engine, or manuals, and you are responsible for checking any third-party references. License summary

Can a team use it?

Yes, but licenses are per person. One purchase covers one individual on their devices; other team members require their own copy. Using the exported art in your team’s game is entirely fine.

Does it work offline?

Yes. Editing, rendering, inspection, and export work without an internet connection. A cloud-based AI agent will need its own network access. Tessarune never transmits your art, prompts, or files to Aurum Nocturne.

Can it export MP4 or a 3D model?

No. Export PNG frame sequences and encode video in an external editor. Tessarune uses 3D joints to pose pixel-art parts, but it is not a mesh tool and cannot export FBX or glTF files.

How do updates and support work?

Updates are distributed through the store where you purchased Tessarune, available as free downloads for existing owners. If you encounter bugs or have suggestions, contact Aurum Nocturne through that store page, including your version number, what happened, and reproduction steps. There is no guaranteed response time.

Made with Tessarune