Claude Fable 5.1 in Claude Code 2.1.280
skills off
The model's own page, run in a sandboxed frame only when you ask (a page that needs its own origin opens in a new tab on a separate demo site). Phones get a full-screen player capped at 1.5x pixel density (2x on larger screens) so it stays smooth; the original page runs uncapped. It starts in its auto-tour (T switches to play mode on a keyboard).
Wall time 39m 19sCost $9.01 reported
Review
No verdict yet.
The full review
Stopped by us. Stopped by us (codespaces lane core-hour budget (60) reached; stopped by the lane, artifacts kept); not a model failure.
Scores
Not scored: only runs that finished on their own are scored.
Downloads
Files actually published for this run. Original output, site-made previews and post-run conversions are labelled separately.
The exact prompt
as run, 664 characters. Every result for this prompt
Build a GPU-accelerated fluid simulation in a single HTML file using WebGL, no external libraries. Dragging the mouse or a finger should push colorful dye through the fluid, with a soft glow. Make it look stunning and run smoothly. Build it as a self-contained index.html in the current directory, with WebGL/WebGL2 shaders you write yourself; no libraries and no CDNs; interactive with mouse or touch input. You may serve it locally and open it in headless chromium (/usr/bin/chromium, software WebGL, no GPU) to screenshot and inspect your own output, and iterate on your own before finishing. Close any browser you open as soon as you've taken your screenshot.
How it was made
Versions saved during the run
10 intermediate outputs, in the order the model wrote them.
Step by step
The prompt, every agent turn and tool call (tool name and a one-line summary; inputs and outputs are not shown), then the final message. The full machine-format transcript is published as a scrubbed download.
Show all 44 steps
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Download the full transcript Claude Code session JSONL, 492 KB. Scrubbed: anything that looks like a key, token, e-mail address or phone number is replaced, and account details and the test machine's file paths are removed.
Cost breakdown
Headline cost $9.01, as reported by Claude Code (its own bill for the run). The list-price estimate from the token counts is $9.00.
| Tokens by type | Tokens | $ per 1M | Cost |
|---|---|---|---|
| Input (uncached) | 872 | $10.00 | $0.0087 |
| Cache write | 192,853 | $12.50 | $2.4107 |
| Cache read | 2,922,598 | $0.25 | $0.7306 |
| Output | 116,961 | $50.00 | $5.8480 |
| of which reasoning | 70,650 | billed as output |
- Total computed from tokens
- $8.9981
- Total reported by the harness
- $9.0131
- Difference
- computed $9.00 vs reported $9.01 (diff -0.02)
Claude Code 2.1.280 reported its own total; token counts x list prices shown beside it.
Prices: Project price table (vendor list prices), 2026-09-22.
Run notes
- frozen prompt (written): engine/prompts_written/gpu_fluid_sim.txt: Voxyz's own prompt verbatim (x.com/Voxyz_ai/status/2103088468762960378) + our fixed inputs (self-contained index.html, own WebGL/WebGL2 shaders, no libraries/CDNs, mouse/touch input) (supervisor 725c3fc2 05:53Z; zero results)
- plain wave-1-equivalent cc_config copy (settings.json + .claude.json; no ECC files)
- Run on a GitHub Codespace (codespaces lane of box-fleet); model calls reached the providers through a credential relay on the home machine (no keys in the codespace).
- Mode: interactive TUI in tmux (160x48), inside bubblewrap sandbox
- Context setting: 1M ([1m] model name)
- Isolation audit: outside paths seen