AI Model Reviewer

Claude Fable 5.1 in OpenCode 1.18.32

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).

Recorded from the live demo (stepped clock). Preview video recorded by this site from the live demo. The moving picture above is that preview; the button runs the real page.

Stopped by usAnt vs gardenermax effortNeutral harness

Wall time 41m 52sCost $11.48 reported

Snapshot 4 of 4 saved during Claude Fable 5.1's run
  1. Snapshot 1 of 4 saved during Claude Fable 5.1's run
  2. Snapshot 2 of 4 saved during Claude Fable 5.1's run
  3. Snapshot 3 of 4 saved during Claude Fable 5.1's run
  4. Snapshot 4 of 4 saved during Claude Fable 5.1's run
Still frames from a low-frame-rate recording made during the run (the moving picture above was recorded from the live demo): 4 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 (535 KB).

Review

No verdict yet.

The full review

Stopped by us. Stopped by us (box row cap near (h4-02); 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 run41m 52s$11.482026-09-25
  2. Attempt 2 OK the cell's result58m 55s$19.742026-09-29

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, 1,384 characters. Every result for this prompt

Build a small playable 3D game in Three.js: an ant defends its home from a furious giant gardener. The player controls the ant on the ground of a lush garden, seen from a low third-person camera that makes the grass blades, pebbles and flowers feel huge. The gardener towers over the scene and sweeps a humming string trimmer back and forth, chasing the ant and throwing up clippings. The ant fights back with a tiny slingshot: aim with the mouse, fire pebbles at the gardener and dodge the trimmer's swings. Show a health bar for the ant and a large health bar for the gardener at the top of the screen, with hit flashes, a clear win or lose message and a restart. Warm afternoon sunlight falls through the leaves overhead, casting moving dappled light and soft shadows, with dust drifting in the light beams. Keep the controls simple (WASD or arrow keys to move, click to shoot) and show them on screen. Everything is built in code from Three.js geometry 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 41m 52sFirst artifact at 24m 56s1 saved version

Versions saved during the run

1 intermediate output, in the order the model wrote them.

Version 1 of 1
  1. Version 1 at 25m 04s thumbnailv1 25:04

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 50 steps

Loading the timeline…

Download the full transcript OpenCode session export, 261 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 $11.48, as reported by OpenCode (its own bill for the run). The list-price estimate from the token counts is $11.48.

Tokens by typeTokens$ per 1MCost
Input (uncached)50$10.00$0.0005
Cache write356,941$12.50$4.4618
Cache read2,101,706$0.25$0.5254
Output129,813$50.00$6.4906
of which reasoning81,098billed as output
Total computed from tokens
$11.48
Total reported by the harness
$11.48
Difference
matches

OpenCode 1.18.32 reported its own total; token counts x list prices shown beside it. The harness reports reasoning tokens separately from output; here output includes them (48,715 visible + 81,098 reasoning), and both bill at the output rate.

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_ant_vs_gardener__opencode__fable-5-1)

  • frozen prompt (rewritten): engine/prompts_rewritten/threejs_ant_vs_gardener.txt: written by us from the recorded description (zero results)
  • plain OpenCode config copy (providers only; no ECC instructions/agents)
  • opencode export written to a file (not piped)
  • Mode: interactive TUI in tmux (160x48), inside bubblewrap sandbox
  • Isolation audit: outside paths seen