Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Run a bookkeeping client's fixed-asset depreciation for 2026 with a mid-month convention, straight-line and declining-balance methods, and disposals

AClaude Opus 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-24 · by @bobsiopener

Trust 80%Fully autonomoussuccess · first tryCompare

Estimated cost: $0.12
Wall time: 19s
Human step-ins: 0
Outcome: Pass

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Exact prompt

# Run a bookkeeping client's fixed-asset depreciation for 2026 with a mid-month convention, straight-line and declining-balance methods, and disposals Inputs: `assets.csv` (asset_id, category, cost, salvage, life_months, method, in_service, disposed_on, proceeds) for a small business client of a bookkeeping firm. All records are synthetic; amounts are in dollars. These rules are the firm's policy; where `controller-note.txt` disagrees, the rules win. Rules: - Mid-month convention: an asset placed in service on day 1-15 of a month starts depreciating that month; on day 16 or later, it starts the next month. An asset disposed of on day 1-15 of a month gets no depreciation for that month; on day 16 or later it gets that month's depreciation, and none after it. - Schedule: depreciation is charged month by month from the asset's first month (which may be before 2026) until life_months monthly charges have been made or the asset is disposed of. Book value = cost − accumulated depreciation. - Straight line (method SL): every monthly charge is (cost − salvage) / life_months, rounded half-up to the cent, except the last month of the life, whose charge is whatever brings accumulated depreciation to exactly cost − salvage. - Double declining (method DDB): a month's charge is the larger of (a) the opening book value × 2 / life_months and (b) (opening book value − salvage) / the number of monthly charges left including this one, each rounded half-up to the cent, but never more than opening book value − salvage. - Disposal: gain_loss = proceeds − (cost − accumulated depreciation at disposal), counting only the depreciation the convention allows. A disposed asset leaves the register: its accum_2026_12_31 and nbv_2026_12_31 are 0, but its 2026 charges still count in dep_2026. - Write `out/fixed-assets.json`: `{"assets": {"<asset_id>": {"dep_2026": <depreciation charged in 2026>, "accum_2026_12_31": <dollars>, "nbv_2026_12_31": <dollars>}, ...}, "disposals": {"<asset_id>": <gain_loss>, ...}, "by_category": {"<category>": <sum of dep_2026>, ...}}`. ## 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.

Run a year of depreciation on a small business's synthetic fixed-asset register for its bookkeeping firm. A mid-month convention decides the first and last charged months, straight-line charges are rounded with a last-month true-up, double-declining charges move to the remaining-life charge once that is larger and stop at salvage, and disposals produce a gain or loss and leave the register. Dates sit on the 15th/16th boundary. A controller's note gets the convention, the switch and the salvage rules wrong. 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: mid_month_convention straight_line declining_balance disposals register_totals

Setup notes: Batch 35 case tw01-bookkeeping-fixed-asset-depreciation (offline, synthetic inputs, seed 250515356). 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 0.40 (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-opus-5.5: $0.120017. Score: 5/5. 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: $0.12
Wall time: 19s
Human step-ins: 0
Turns: 3

Model usage
Model	Input tok	Output tok	Cost
AClaude Opus 5.5anthropic/claude-opus-5.5effort default (no --effort flag) · thinking on	58,492	1,975	$0.12

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: mid_month_convention straight_line declining_balance disposals register_totals
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/fixed-assets.json` for all 9 assets, plus the three disposals and the category totals. I hand-checked the hardest cases (FA-947, FA-648 and FA-365) against the rules. Nothing else checks this file, so the remaining figures are as the script produced them.\n\nWhere `controller-note.txt` disagreed with the firm's rules, I followed the rules. That means:\n- **Timing:** I used the mid-month convention, not a full month for every purchase or sale.\n- **DDB:** each month's charge is the larger of the declining-balance and remaining-life amounts, and never takes book value below salvage. The note's simple 2/life of book each month was not used.\n- **Gain/loss on sale:** proceeds are compared with book value at disposal, not with the original cost.\n\n**2026 depreciation by category**\n\n| Category | 2026 depreciation |\n|---|---|\n| Vehicles | $16,973.07 |\n| Workshop machinery | $3,491.28 |\n| Office furniture | $989.94 |\n| Computers | $7,422.35 |\n\n**Disposals (all losses)**\n\n| Asset | Gain/loss | 2026 depreciation |\n|---|---|---|\n| FA-580 | \u2212$9,720.14 | Jan\u2013Feb |\n| FA-947 | \u2212$16,678.28 | Jun\u2013Sep |\n| FA-648 | \u2212$3,717.24 | Jan\u2013Nov |\n\n- **Disposed assets:** these three are off the register, with year-end accumulated depreciation and book value both 0. Their 2026 depreciation is still included in the totals.\n- **FA-365:** its life ends in April 2026, so it closes the year fully depreciated, with a book value equal to its $1,205.00 salvage.\n\nThe calculation script is at `/tmp/fa/run.py`, outside the work folder, since only `out/` was to be written.",
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