Claude Haiku 5.5 (effort default (no --effort flag) · thinking on) on Animate a flickering carved pumpkin on a spooky night in one self-contained HTML file

AClaude Haiku 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-22 · by @bobsiopener

Trust 80%Fully autonomoussuccess · first tryCompare

Estimated cost: $0.0087
Wall time: 42s
Human step-ins: 0
Outcome: Pass

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Exact prompt

# Animate a flickering carved pumpkin on a spooky night in one self-contained HTML file Make a small animated scene: a jack-o'-lantern. 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): `{flame: <number 0..1, the candle brightness now>, pumpkin: {x, y, r}}`. Extra fields are fine. It must describe what is actually drawn. - `pumpkin` is the pumpkin's centre and radius in stage pixels. It is night: keep the page corners and the top-centre edge dark. - 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. `flame_flickers`: across 30 samples over 3 s, `sceneState().flame` stays within 0 to 1, takes at least 6 distinct values (to 3 dp) and spans at least 0.15. 5. `glow_and_night`: the pumpkin (`r` at least 40, centre inside the stage) visibly changes within its box between the first screenshot and a later one over 3 s, and the four page corners and the top centre stay dark (average RGB below 90). 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 jack-o'-lantern 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 over time, the scene behaves as specified (flame flickers; glow and night) 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 flame_flickers glow_and_night no_console_errors

Setup notes: Batch 28 case d03-flickering-jack-o-lantern (offline, synthetic inputs, seed 3118618518). 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 0.80 (8 cores). Creative case: looks are not scored; objective checks run in headless google-chrome (800x600, UTC, network blocked, Date mocked). Gallery media (3 s capture: poster.png + clip.mp4) written by the scorer to a fresh MEDIA_DIR per run (media/<run>/), SHA-256 in evidence.media; a single failed scene check is rescored once (both recorded in 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-haiku-5.5: $0.008652. 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: $0.0087
Wall time: 42s
Human step-ins: 0
Turns: 6

Model usage
Model	Input tok	Output tok	Cost
AClaude Haiku 5.5anthropic/claude-haiku-5.5effort default (no --effort flag) · thinking on	126,112	8,129	$0.0087

Reproduce this run

Use the use case prompt on the use case page.
Same setup: Claude Haiku 5.5 (anthropic/claude-haiku-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 flame_flickers glow_and_night 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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   "output_tokens": 8129,
   "output_tokens_details": {
    "thinking_tokens": 4002
   },
   "server_tool_use": {
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   },
   "service_tier": "standard",
   "cache_creation": {
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   "iterations": [
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     "cache_read_input_tokens": 29277,
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     "cache_creation": {
      "ephemeral_5m_input_tokens": 0,
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     },
     "type": "message"
    }
   ],
   "speed": "standard",
   "fallback_credit": null
  },
  "modelUsage": {
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    "inputTokens": 10,
    "outputTokens": 8129,
    "cacheReadInputTokens": 108598,
    "cacheCreationInputTokens": 17504,
    "webSearchRequests": 0,
    "costUSD": 0.008652279999999998,
    "contextWindow": 1000000,
    "maxOutputTokens": 128000,
    "thinkingTokens": 4002,
    "canonicalModel": "claude-haiku-5-5",
    "provider": "firstParty",
    "costBasis": "list"
   }
  },
  "permission_denials": [],
  "terminal_reason": "completed",
  "fast_mode_state": "off",
  "fast_mode_disabled_reason": "sdk_opt_in_required",
  "subagent_stats": {
   "spawned": 0,
   "requested": {
    "background": 0,
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   "started_in_background": 0,
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   "killed": {
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   "by_type": {}
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  "safety_stops": 0,
  "is_error": false,
  "num_turns": 6,
  "subtype": "success",
  "api_error_status": null,
  "result": "I wrote `out/scene.html`, a self-contained 640x400 animated jack-o'-lantern with a flickering candle. A single headless Chrome screenshot rendered correctly, but I did not run the time-based checks.\n\n- **Stage and title:** a canvas at the spec's 640x400 size, visible on load, with `<title>Jack-o'-lantern 162</title>`.\n- **Animation:** continuous `requestAnimationFrame` loop. The flame is a sum of three sines clamped to 0..1, so it should vary across the 3 s window.\n- **`window.sceneState()`:** returns `{flame, pumpkin: {x: 320, y: 232, r: 110}, stage: {width, height}}`. `flame` is the same value used to draw that frame.\n- **Night:** the glow radius is about 231 px from the pumpkin centre, so the page corners and the top-centre edge stay dark. The screenshot confirms this.\n- **Size and network:** 5,047 bytes, with no `http`/`https` strings and no external resources.\n- **Console errors:** the headless run logged only D-Bus noise from the sandbox, with no page exceptions. I did not hook `console.error` or `window.onerror` directly.\n\nI did not run the 30-sample flame sampling or the screenshot-diff checks, so `frames_change`, `flame_flickers` and `glow_and_night` are unverified by measurement, though the code should satisfy them.",
  "ttft_ms": 1763,
  "type": "result",
  "duration_ms": 41209,
  "uuid": "[REDACTED]",
  "ttft_stream_ms": 1512,
  "time_to_request_ms": 315,
  "first_content_frame_ms": 1512,
  "queued_turn_count": 0,
  "result_index": 0
 }
]