Fable5 Demos — Development skill for Claude Code

One-Shot Simulations · by Claude Fable 5

**Live gallery → https://karanb192.github.io/fable5-demos/**

A collection of **real interactive simulations, each written in a single attempt by [Claude Fable 5](https://www.anthropic.com)** — chaos theory, fluid dynamics, emergent flocking, Fourier analysis, algorithm visualization. One prompt in, one working simulation out.

Every piece follows the same three constraints:

1. One shot. The model wrote it in a single attempt — no iterating until it looks right. (An adversarial verifier agent was allowed to fix genuine bugs; that's it.)
2. One file. Self-contained HTML — inline CSS/JS, zero external requests, no frameworks, no build step. It runs from a file:// URL, offline.
3. Real algorithms. If it says Navier-Stokes, there is a pressure solver in the source. Nothing is faked with noise and blur — open view-source and check.

The collection

Simulation	What you see	What's actually running
🦋 The Butterfly Effect	100 double pendulums released 0.0001° apart agree, then explode into chaos	The exact double-pendulum equations of motion, RK4-integrated at 240Hz in float64 — the divergence you watch is a measured Lyapunov blow-up, not a script
🕊️ Murmuration	A starling flock that reacts to your cursor — the hawk	Reynolds boids: separation / alignment / cohesion computed from actual neighbors over a spatial hash grid — the flock's shapes emerge
🖌️ Ink & Water	Ink you pour into water, swirling like the real thing	Navier-Stokes solved on the GPU in WebGL shaders: advection, vorticity confinement, Jacobi pressure projection
✏️ Circle Scribe	A chain of spinning circles that redraws whatever you sketch	A discrete Fourier transform of