Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Animate a home battery bank's charge and top-off curve in one self-contained HTML file

AClaude Opus 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-25 · by @bobsiopener

Trust 80%Fully autonomoussuccess · first tryCompare

Estimated cost: $0.17
Wall time: 36s
Human step-ins: 0
Outcome: Pass

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Exact prompt

# Animate a home battery bank's charge and top-off curve in one self-contained HTML file Make a small animated scene: a home battery charge and top-off. Write one file, `out/scene.html`, that works opened straight from disk with no network access. `spec.json` gives the page title, the stage size and the scene parameters. **Looks are not scored**: the page is opened in a headless browser (800x600 window, UTC time zone, network blocked) and checked by objective tests only. ## Scene contract - Draw the scene on one `<canvas>` or `<svg>` stage of `width` x `height` CSS pixels (spec.json), visible on load, with `<title>` containing spec.json `title`. - Animate continuously from load (`requestAnimationFrame` or timers); no click is needed unless stated below. - Expose `window.sceneState()`, returning the scene's current state in stage pixel coordinates (origin top-left of the stage): `{batteries: [{name, x, y, level, status: "idle" | "charging" | "topping_off"}, ...]} (canvas px, y down; one entry per spec.json battery; x = the battery's centre; level = the charge height in px; y = the top of the charge, base_y − level)`. Extra fields are fine. It must describe what is actually drawn. - Time 0 is `performance.now()` 0 (seconds = `performance.now()` / 1000). Each battery sits at level `level0_px` until its own `charge_s`; it then charges at a steady `rate_px_s` (pixels of level per second) until the level reaches `cv_px`, which happens at tc = charge_s + (cv_px − level0_px) ÷ rate_px_s; after that the charger tapers off and the level is cv_px + (full_px − cv_px) × (1 − e^(−(time − tc) ÷ tau_s)), approaching but never passing `full_px`. The top y is `base_y` − level. Draw each battery and its charge. `sceneState()` must return the state at the moment it is called. - The page must log no errors and throw no exceptions. Keep the file at most 200,000 bytes; no external scripts, fonts, images or URLs (inline everything). ## Checks (partial credit = share passed) 1. `self_contained`: `out/scene.html` exists, is at most 200,000 bytes, references no http(s) or protocol-relative URL, and requests nothing from the network when opened. 2. `has_canvas_or_svg`: a visible `<canvas>` or `<svg>` of at least 300x200 CSS pixels is on the page. 3. `frames_change`: over 3 s, some later screenshot differs from the first in at least 0.1% of pixels, and at least 3 of 30 screenshots differ. 4. `charge_level`: at every sample more than 0.05 s from a battery starting to charge or reaching `cv_px`, each battery's x is within 1.5 px of its spec.json `x`, and its level and top y are within 1.5 px of the exact values: `level0_px` before `charge_s`, then rising at `rate_px_s` until it reaches `cv_px`, then cv_px + (full_px − cv_px) × (1 − e^(−s ÷ `tau_s`)) with s = seconds since it reached cv_px. 5. `battery_status`: at those samples each battery's `status` is idle before `charge_s`, charging until it reaches `cv_px`, then topping_off; the samples include all three statuses. 6. `no_console_errors`: no uncaught exception, `console.error` or browser error is logged during the run. ## How this run works - Work on your own: nobody will answer questions in this task, and writing to `ask/` counts against the run. - Write only under `out/`. Create `out/` if it is missing. Inputs are synthetic; don't fetch anything from the network. - Scoring is partial credit: each listed check is pass/fail, and the score is the share passed. Numbers are compared to within 0.005 unless the task says otherwise.

Make a home battery charge and top-off animation as one self-contained HTML file. A headless browser checks objective facts only: the file is offline and small, a canvas or SVG stage is drawn, frames change, the scene follows a timed specification (charge level; battery status) and nothing errors. A poster PNG and a short MP4 are captured for the gallery. Looks are not scored. Original benchmark task written for usecaserank.com (not based on a specific public post). Headless, offline run on a reproducible fixture. Each run's notes say how its cost was measured (estimates are marked).

Success criteria: self_contained has_canvas_or_svg frames_change charge_level battery_status no_console_errors

Setup notes: Batch 40 case tn07-home-battery-charge-animation (offline, synthetic inputs, seed 2407130708). Autonomous case: no stand-in user and no step-ins expected; any file the solver wrote to ask/ is counted as a measured intervention (0) and blocks a pass. Prompt = TASK.md verbatim. Hidden key kept outside the solver's work dir. Scored with the case's scorer (python3 score.py WORKDIR KEYDIR, absolute paths); pass = every check true and no ask/ files. Tools: Read/Write/Edit/Glob/Grep/Bash, web disabled. Single run, no retries. 1-min load average at scoring 0.29 (8 cores). Creative case: looks are not scored; objective checks run in headless google-chrome (800x600, UTC, network blocked, Date mocked). Gallery media (poster.png + clip.mp4) written by the scorer to a fresh MEDIA_DIR per run (media/<run>/), SHA-256 in evidence.media. Scored alone (no other check groups running), single scoring, no rescore. Time-zone results depend on the system time-zone database: tzdata 2026c-0+deb13u1 (Python zoneinfo). Claude Code's own reported cost for claude-opus-5.5: $0.170027. Score: 6/6. Cost is an ESTIMATE: measured tokens x pricing.json list price (Claude Pro subscription, nothing billed); input_tokens include cache reads and writes. Single run.

Estimated cost List-price estimate; not actually billed.

Output

Metrics

Estimated cost: $0.17
Wall time: 36s
Human step-ins: 0
Turns: 7

Model usage
Model	Input tok	Output tok	Cost
AClaude Opus 5.5anthropic/claude-opus-5.5effort default (no --effort flag) · thinking on	148,045	2,690	$0.17

Reproduce this run

Use the use case prompt on the use case page.
Same setup: Claude Opus 5.5 (anthropic/claude-opus-5.5, effort default (no --effort flag) · thinking on) via Claude Code 2.1.299 (headless -p), cloud.
It counts as a success only if it meets every success criterion: self_contained has_canvas_or_svg frames_change charge_level battery_status no_console_errors
Log model, tokens, wall time, human step-ins and the evidence log, then submit it as a reproduction. A different model? Submit a head-to-head rerun.

How runs are scored: Methodology.

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Automated checks

Trust 80% comes from these checks (how Trust % works).

Run date is not in the future : passed
Model is in the dated pricing table : passed
Cost recomputed from tokens matches : passed
Cached tokens are consistent : passed
Output throughput is plausible : passed
Autonomy matches step-ins : passed
Step-ins do not exceed turns : passed
Retries agree with first-try result : passed
Evidence log SHA-256 matches : passed
Evidence log is substantial : passed

Evidence log

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  "result": "I wrote `out/scene.html` (about 2.8 KB). It animates the four batteries from `spec.json` on a 760x500 canvas, and the page title contains \"Home Battery Bank 138\".\n\n**Verification so far:** I opened the page once in headless Chrome at 800x600 and took a screenshot. It showed the stage drawn correctly at t=0.07 s, with all four batteries idle at their starting levels (10, 10, 20 and 30 px). Chrome didn't log any page errors, apart from its own unrelated messages about the system bus. I did not test charging or topping off, and I didn't run the checks' 3-second frame-difference test. I also didn't sample `sceneState()` against the expected values, so those three checks haven't been run.\n\n- **How the levels are calculated:** each battery's level and status come straight from `performance.now()` using the formula in the brief. It stays at `level0_px` until `charge_s`, rises at `rate_px_s` until it hits `cv_px`, then tapers exponentially towards `full_px`. Status goes idle \u2192 charging \u2192 topping_off at those same two moments.\n- **What `sceneState()` returns:** it works out the state at the moment it's called, and returns each battery's x (centre), level and top y (`base_y` \u2212 level) along with its status. The drawing for each frame uses that same calculation, so the canvas and `sceneState()` always agree.\n- **Keeping the frames changing:** once the batteries are nearly full they barely move. To make sure screenshots still differ over 3 seconds, a small dot in the corner keeps changing colour and size, and a timer next to the title counts up.\n- **Self-contained:** the spec is written into the file, and there are no external URLs, fonts or images.",
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