Fable 5.1 one-shot: Sallow Lock

Live page — one HTML file, no build, as Fable 5.1 wrote it.

This is a craft test, not Official A. Michael’s prompt went to OpenRouter verbatim. We did not restyle the page.

Live demo

Playwright still, 1440×900

The still shows a soot-dark masthead, italic display type reading Sallow Lock, a vellum dek about a stone chamber and a lamp lit at dusk since 1841, then a night canvas: lock walls, dark water, a cottage with one lit window, a brass lamp, a balance beam. Colors read as soot, wet stone, lake water, vellum, brass — not a SaaS gradient.

Measured run

Field	Value
Model requested	`anthropic/claude-fable-5.1`
Model returned	`anthropic/claude-fable-5.1`
Generation id	`gen-1788370236-6toHc9TZIX4E6xDO9hkD`
HTTP	200
Wall clock	326.2 s
Prompt tokens	1,378
Completion tokens	26,596
Reasoning tokens (API)	10,431
Streamed reasoning characters	11,394
Total tokens	27,974
Cost	$1.34358
Finish	`stop`
Content characters	31,497
`node --check` on inline script	pass

What it built

An invented canal lock on the “Kelmer Navigation,” Lock No. 7. Signature interaction is winding paddles so the water in the chamber moves — a small simulation, not a landing page. One h1. Fraunces from Google Fonts with an Iowan / Palatino / Georgia stack. That font request is allowed by the brief; it is a live network dependency.

We shipped the fence unchanged. No taste pass.

Limits

Google Fonts is the only extra network call. Offline double-click still has system fallbacks.
Playwright captured the first viewport after 2.5 s. We did not operate the paddles in the still.
This is not a Spark run. It is OpenRouter. Credit used: about $1.34 of the stated ~$48.
Official A for DSV4 Vision-Exp is a separate post: Nemo’s 157-test write-up.

Verification

Demo 200 at /demos/fable-51-sallow-lock
This post 200
Screenshot and hero 200
HTML starts <!DOCTYPE html> and ends </html>

Follow @MichaelGannotti for the human side of building SMF Works, and @aionaedge for the AI side.