Claude Sonnet 5.5 (effort default (no --effort flag) · thinking on) on Build a step-by-step interactive explainer web app that teaches a beginner how to choose an LED's series resistor
AClaude Sonnet 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-22 · by @bobsiopener
- Estimated cost
- $0.06
- Wall time
- 18s
- Human step-ins
- 0
- Outcome
- Pass
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Summary
Exact prompt
# Build a step-by-step explainer web app: choosing a series resistor for an LED Make a small interactive web app that teaches a beginner one hardware topic, one step at a time: how to pick the series resistor for an LED. `spec.json` gives the page title, the steps (each with a title and a fact sentence), and the standard resistor series to use (`series_base`, one decade of values, repeated across `decades`). Look, layout and wording beyond the spec are up to you; **looks are not scored**. The page is scored in a headless browser (800x600 window, network blocked) by objective checks only. Write one file, `out/explainer.html`, that works opened straight from disk. ## Steps - Show one step at a time. On load, step 1 is shown. Put the current step's title in `#step-title`, its text in `#step-body` and a counter in `#step-count`. - Buttons `#prev` and `#next` move one step back or forward. - Every step title must appear in `#step-title` in the order given in spec.json, and `#step-count` reads "Step <i> of <N>". - `#prev` is disabled (the `disabled` property) on step 1 and `#next` is disabled on the last step; neither moves past the ends. - `#step-body` for each step contains that step's fact sentence from spec.json exactly as written (extra text around it is fine). ## Calculator Inputs `#in-supply` (supply volts), `#in-vf` (LED forward volts), `#in-ma` (LED current in mA) and `#in-count` (LEDs in series, a whole number); outputs `#out-ohms`, `#out-standard`, `#out-mw` and `#out-error`. The calculator is visible on every step and recalculates on each `input` or `change` event (a `#calc` button is optional; it is clicked too if present). - For supply V, forward voltage F, current I mA and count n: R = (V - n x F) / (I / 1000). `#out-ohms` shows R rounded half-up to a whole ohm. - `#out-standard` shows the smallest standard series value that is at or above the exact R, never a smaller one. - `#out-mw` shows the resistor's power, (V - n x F) x I, in mW rounded half-up to a whole number. - Show numbers as plain digits (for example `1200`, not `1.2k`); a unit after the number is fine. - If any input is missing or not positive, or V is not greater than n x F, `#out-error` shows a non-empty message and `#out-ohms`, `#out-standard` and `#out-mw` are empty. Otherwise `#out-error` is empty. ## Checks (partial credit = share passed) 1. `self_contained`: `out/explainer.html` exists, is at most 150,000 bytes, references no http(s) or protocol-relative URL, and requests nothing from the network when opened. 2. `required_elements`: every element id named above is present, and the `<title>` contains spec.json's `title`. 3. `steps_in_order`: Every step title must appear in `#step-title` in the order given in spec.json, and `#step-count` reads "Step <i> of <N>". 4. `navigation_limits`: `#prev` is disabled (the `disabled` property) on step 1 and `#next` is disabled on the last step; neither moves past the ends. 5. `step_facts`: `#step-body` for each step contains that step's fact sentence from spec.json exactly as written (extra text around it is fine). 6. `calculator_values`: on hidden test inputs, `#out-ohms`, `#out-standard` and `#out-mw` all match the rules above. 7. `invalid_input`: If any input is missing or not positive, or V is not greater than n x F, `#out-error` shows a non-empty message and `#out-ohms`, `#out-standard` and `#out-mw` are empty. No build step and no other files are scored. ## 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.
Build a one-file web app that walks a beginner through choosing an LED's series resistor, one step at a time, with a live calculator. A headless browser clicks through the steps and feeds hidden inputs to the calculator, checking step order, the button limits at both ends, the given facts, the calculated values (including rounding up to a standard resistor value) and the error state. 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 required_elements steps_in_order navigation_limits step_facts calculator_values invalid_input
Setup notes: Batch 26 case b01-led-resistor-explainer (offline, synthetic inputs, seed 718230610). 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 0.15 (8 cores). Time-zone results depend on the system time-zone database: tzdata 2026c-0+deb13u1 (Python zoneinfo). Claude Code's own reported cost for claude-sonnet-5.5: $0.06047. Score: 7/7. 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.
Metrics
- Estimated cost
- $0.06
- Wall time
- 18s
- Human step-ins
- 0
- Turns
- 3
| Model | Input tok | Output tok | Cost |
|---|---|---|---|
| AClaude Sonnet 5.5anthropic/claude-sonnet-5.5effort default (no --effort flag) · thinking on | 60,676 | 1,949 | $0.06 |
Reproduce this run
- Use the use case prompt on the use case page.
- Same setup: Claude Sonnet 5.5 (anthropic/claude-sonnet-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 required_elements steps_in_order navigation_limits step_facts calculator_values invalid_input
- 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/explainer.html`, but I haven't opened it in a browser or run any of the checks against it. I only confirmed that the file is 3,608 bytes and contains no \"http\" text.\n\n- **Steps:** step 1 shows on load, with the title, fact sentence and \"Step i of N\" counter filled in from `spec.json`. `#prev` is disabled on the first step and `#next` on the last.\n- **Calculator:** it recalculates on every `input` or `change` event, and the optional `#calc` button is there too. It follows your formulas for R and power, rounds half-up, and shows plain digits.\n- **Standard value:** it picks the smallest E24 value at or above the exact R, using the decades 10 to 100000, so the range tops out at 910000 ohms. If R is above that, `#out-standard` shows \"above range\" rather than an error.\n- **Invalid input:** a missing or non-positive input, a non-whole LED count, or V not greater than n \u00d7 F puts a message in `#out-error` and empties the three result outputs.\n\nThe `#in-count` field starts at 1, and the page runs the calculator once on load. With the other inputs empty, `#out-error` will already show a message when the page opens.",
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