AI Model Reviewer

Claude Fable 5.1 in Claude Code 2.1.280

skills off

← Open in the gallerySame prompt, all models

Poster frame of Claude Fable 5.1's page
Open the original page

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).

Stopped by usJellyfishmax effortNeutral harness

Wall time 43m 04sCost $18.29 reported

Snapshot 2 of 2 saved during Claude Fable 5.1's run
  1. Snapshot 1 of 2 saved during Claude Fable 5.1's run
  2. Snapshot 2 of 2 saved during Claude Fable 5.1's run
Still snapshots saved during the run (no motion recording): 2 distinct frames.

Generation timelapse

Poster for generation timelapse

Generation timelapse (the agent's screen during the run, sped up). This is not the finished video. Download video (1.0 MB).

Review

No verdict yet.

The full review

Stopped by us. Stopped by us (box row cap reached (2855s); stopped by the box lane so the run ships as partial); not a model failure.

Attempt 1 of 2

Every try of this model in this harness on this prompt, oldest first. A later attempt is the cell's result: attempt 2.

  1. Attempt 1 Stopped by us this run43m 04s$18.292026-09-26
  2. Attempt 2 OK the cell's result50m 56s$17.422026-09-29

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, 1,367 characters. Every result for this prompt

Build a Three.js scene of a huge glowing jellyfish walking through a rainy city at night on very tall, thin, jointed legs, presented as a live disaster news broadcast. The jellyfish's translucent bell pulses with soft bioluminescent light, its tentacles sway beneath it, and each slow stride steps between the towers while rain streaks through the light and wet streets reflect neon signs and headlights. Frame it like a TV emergency broadcast: a main camera feed plus several smaller feeds from other angles (street level, a helicopter, a rooftop) that update as the creature moves; a HUD with a channel logo, a red LIVE badge, a scrolling news ticker, a clock and coordinates; and an event log panel that adds timestamped entries as the jellyfish crosses the city. Keep the mood tense and cinematic, with fog, flickering streetlights and flashing red and blue emergency lights. Everything is built in code from Three.js geometry, shaders and materials; no external models or textures. Build it as index.html (plus any local asset files you create) in the current directory. Three.js may load from a pinned CDN. 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

Wall time 43m 04sFirst artifact at 23m 19s5 saved versions

Versions saved during the run

5 intermediate outputs, in the order the model wrote them.

Version 5 of 5
  1. Version 1 at 23m 22s thumbnailv1 23:22
  2. Version 2 at 29m 04s thumbnailv2 29:04
  3. Version 3 at 33m 46s thumbnailv3 33:46
  4. Version 4 at 36m 53s thumbnailv4 36:53
  5. Version 5 at 41m 19s thumbnailv5 41:19

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 24 steps

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Download the full transcript Claude Code session JSONL, 509 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 $18.29, as reported by Claude Code (its own bill for the run). The list-price estimate from the token counts is $18.27.

Tokens by typeTokens$ per 1MCost
Input (uncached)482$10.00$0.0048
Cache write608,477$12.50$7.6060
Cache read1,274,391$0.25$0.3186
Output206,832$50.00$10.34
of which reasoning135,945billed as output
Total computed from tokens
$18.27
Total reported by the harness
$18.29
Difference
computed $18.27 vs reported $18.29 (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

one prompt, agentic harness (self-review allowed)prompt rewritten after the 2026-09-24 box losslabelled re-run (of threejs_jellyfish__claude-code__fable-5-1)

  • frozen prompt (rewritten): engine/prompts_rewritten/threejs_jellyfish.txt: written by us from the recorded description (zero results)
  • plain wave-1-equivalent cc_config copy (settings.json + .claude.json; no ECC files)
  • Mode: interactive TUI in tmux (160x48), inside bubblewrap sandbox
  • Context setting: 1M ([1m] model name)
  • Isolation audit: outside paths seen