Glyphloop

A browser studio and headless toolkit for creating loop-perfect generative ASCII animations: flow fields, wave interference, morphing noise blobs, matrix rain, rotating 3D shapes, custom math expressions, and parametric surfaces. Layer effects over images, video, or text, inherit their colors, and export to PNG, GIF, MP4, self-contained web embeds, or terminal players.

Also usable headless by AI agents through the package CLI or MCP server - agents can even define their own animations and 3D shapes as expression strings. See AGENTS.md.

Glyphloop = glyphs + seamless loops.

Try the hosted studio with no account, or see live examples.

Local Studio

npm ci
npm run dev        # opens on http://localhost:5199

Node.js 20 or newer is required. Chrome is recommended because MP4 export uses WebCodecs; the other workflows work in modern browsers.

Related MCP server: ASCII Motion MCP

CLI and MCP

The package exposes one glyphloop executable with two commands:

npx glyphloop@beta render --preset flowfield-hero --out hero
npx glyphloop@beta mcp

From a source checkout, the equivalent development commands are:

npm run render -- --preset flowfield-hero --out hero
npm run mcp

render accepts a built-in preset name, a preset JSON file, or inline JSON. Run node bin/glyphloop.js --help for the complete command summary.

Use

1. Pick an effect source and tweak its parameters live - or drag & drop any image/video onto the editor to ASCII-fy your own design with its colors intact.

2. Style it: character ramp (or type your own), gamma, invert, mono or two-color gradient.

3. Set grid columns, cell size, aspect ratio, duration, and FPS. Imported media starts at its native aspect ratio, and raster exports can match its exact pixel dimensions.

4. Export:

   • PNG - current frame, at 1–3× scale.

   • GIF / MP4 - one animation pass, rendered deterministically frame-by-frame (never drops frames). Generated motion wraps seamlessly.

   • Web embed (zip) - frames.json (RLE-compressed character frames) + player.js (tiny dependency-free player, honors prefers-reduced-motion) + a demo index.html. Drop the two files into any site and add <div data-ascii-player></div>.

   • Terminal (zip) - frames.ans + play.sh; run bash play.sh to loop the animation in a terminal.

The editor includes six starter presets. Presets can also be saved to localStorage or downloaded/loaded as JSON via the header bar. A shared preset can be opened with /studio/?preset=flowfield-hero.

Imported media stays in the browser; Glyphloop does not upload it. For a stable beta experience, images are limited to 25 MiB and 40 decoded megapixels, videos to 100 MiB and the first 20 seconds, and preset files to 10 MiB. Very large render workloads are rejected with guidance to reduce scale, columns, FPS, or duration.

The hosted website and Studio send a small allowlisted set of anonymous product events to a first-party Cloudflare endpoint. Creative inputs and outputs are never included. Source checkouts, the CLI, and the MCP server send no analytics. See the hosted privacy notice.

Source color vs image palette

These are two different ways to color imported media:

• Color mode: source samples the image or video at every grid cell, so each glyph keeps the local color beneath it. It preserves multicolor artwork and follows changing video colors frame by frame.

• Set ink & paper from image extracts a small representative palette and fills the Ink, Ink 2, and Paper controls. Choose mono or gradient to render with those curated colors instead of retaining every source color.

In short: source mode preserves the image's color map; the palette action uses the image as inspiration for a controlled Glyphloop color scheme. The Studio's Undo image palette action restores the exact ink and paper colors that were set before palette extraction.

Why generated loops are seamless

Glyphloop's built-in sources and periodic expressions are pure functions of time with no per-frame state. All noise is sampled along a circle in two extra noise dimensions (src/core/noise.ts:loopCoords), and all sine phases advance by integer multiples of 2π per loop - so frame N wraps back to frame 0 exactly. Exports render round(fps × duration) frames starting at t=0 and never render t=duration (frame 0 is the wrap).

Imported video is not made loop-perfect automatically. Glyphloop samples one pass of the clip across the animation duration, then playback repeats from the start. The composite is seamless only when the source video was already designed to loop, as in the Claude jellyfish example, or when the imported base is a still image.

Development

npm test           # vitest unit tests (noise periodicity, mapper, RLE, ZIP, ANSI, sources)
npm run build      # typecheck + production build
npm run build:site # typecheck + production website and Studio build

Architecture: Source → FieldFrame (brightness grid) → AsciiMapper → CanvasRenderer → exporters.

Licence, outputs, and brand

Glyphloop's software, including the editor, renderer, CLI, MCP server, exporters, presets, and generated embed player, is available under the MIT licence.

Glyphloop claims no ownership in content you import or animations you export. You may use exported animations commercially without attribution, subject to any rights applicable to your source materials.

The Glyphloop name and visual identity are not licensed under MIT. Demo and marketing media are separately labelled. See TRADEMARKS.md and LICENSES/ASSETS.md.

Issues and focused feedback are welcome during the beta. See CONTRIBUTING.md and SECURITY.md.