FABLE-SHOWCASE: 57 single-file demos from one prompt and about 275 subagent runs

One prompt, one day, and roughly 275 subagent runs

The method is described in one paragraph, and it is the actual subject of the repository. A single prompt was issued in Claude Code, and from it about 275 subagent runs fanned out across background multi-agent workflows, each demo travelling through a pipeline of design, then build, then enhance, then QA. The stated stopping condition is the interesting part: the runs continued until the week's API credits were spent. So the volume of output is framed as a consequence of a budget rather than of a plan, and the readme's own framing question is what happens when you ask a model to consume a week's worth of usage credits in one day. The repository description puts the same idea more tersely, calling the whole thing an experiment in pushing the limits of one-shot prompting.

The readme claims 57 demos, and the tree holds 57

The count is one of the few claims here that can be checked against the repository itself, and it holds up. The root contains two files and a long list of directories: the readme, the gallery page, a folder of captured thumbnails, and one directory per demo. Counting the directories and setting the thumbnail folder aside gives 57, which matches the number in the readme exactly. What the count does not tell you is anything about the demos themselves, since a directory name is the only metadata attached to each one, and the readme offers no per-demo description, no difficulty marker and no indication of which ones are worth opening first.

Every demo is one index.html with no build step and no network

The constraint that shapes everything else is stated as a rule rather than a preference: every demo is a single `index.html` file with zero dependencies, no build step, no CDN, no frameworks and no network requests, and any of them can be opened directly in a browser. That is a real engineering constraint rather than a stylistic one, because it rules out the obvious approaches for this kind of work, including any library that would normally be pulled from a content delivery network and any build step that would normally produce a bundle. It also makes the demos trivially forkable, since a fork is a file copy, and trivially archivable, since nothing outside the repository is needed to run them.

Six named collections cover fewer than half of the demos

The readme organises the demos into six collections, and the mismatch with the tree is the most useful thing in it. Simulation and life lists boids, particle life, slime mould, a reef, a tidepool and an L-system garden. Generative art lists a fractal voyager, an I-Ching oracle, tarot cards, stained glass, geometric weaving, calligraphy and a mandala. Physics and motion lists orbital sandboxing, black hole lensing, cymatics, gears and a ripple tank. Worlds and skies lists an aurora, an infinite cathedral, an ocean, a metropolis, a pocket planet and hexcrawl maps. Sound and music lists four entries, and play and curiosities lists six. Add those up and roughly three quarters of the named examples are covered, but whole directories in the tree, among them biome-globe, crystallize, ink-flow, kinetic-type, koi-pond, paper-garden, wfc-weaver and wordsmith, appear in no collection at all.

Previews are headless captures embedded as data URIs

The gallery has to work the same way the demos do, which drives how its images are stored. Thumbnails were produced by rendering each demo in a headless browser, and the resulting captures are embedded into the gallery page as data URIs, which is why the preview images also appear as a directory in the tree while the page itself stays self-contained. The gallery page is described as searchable and category-filtered with the thumbnails inline, so the whole thing is one file you can open with no server. The trade-off is inherent to that choice: a capture is a snapshot of one moment, so a demo whose appeal lies in motion is represented by whichever frame the renderer happened to take.

The prompt is quoted in full, in the original lowercase

The readme reproduces the prompt that started all of it, and it is reproduced rather than tidied. It opens by announcing a challenge, states the requirement to use up the week's Anthropic API credits in one day, restricts the work to one model, asks for a build that leverages an already authenticated command line tool, and ends by asking for plenty of work in parallel. It is written entirely in lowercase with no punctuation discipline, which is worth noting because it is the input that produced fifty-seven finished demos. Whatever the pipeline did, it did not require a carefully specified brief, and the readme does not claim otherwise.

No licence, no releases, and the last push is July 7, 2026

The repository's administrative state is thin, and one item matters if you plan to reuse anything. No licence is identified, so the terms for copying, modifying or redistributing a demo are not stated anywhere, which for a gallery whose whole purpose is to be looked at and copied is the gap to notice first. There are no GitHub releases either, so there is no version to point at and no changelog to read, and the default branch is main with the most recent push dated July 7, 2026. The project is primarily HTML, which matches the single-file rule, and the readme closes by saying it was built with Claude Code.

Editorial conclusion

Use this repository as a source of single-file browser toys to read, fork and copy from, since the zero-dependency constraint is enforced per demo and the whole gallery is one self-contained page. Do not treat it as a curated exhibition, because the six named collections account for fewer than half of what is in the tree, and do not reuse the demos commercially without checking first, since no licence is identified for the repository. Before you take anything from it, look at how a demo is written rather than how it looks, remember that every preview is a static capture, and expect the collection categories in the readme and the directory names in the tree to disagree.

Frequently asked questions

Official sources

1. Dépôt GitHub elder-plinius/FABLE-SHOWCASE
2. Galerie index.html du dépôt
3. README du projet