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Claude Sonnet 5.5 (effort default (no --effort flag) · thinking on) on Apportion a building's quarterly service charge with non-recoverable costs, a mid-quarter tenant change, a vacant unit and capped leases

AClaude Sonnet 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-21 · by @bobsiopener

Trust 80%Fully autonomoussuccess · first try
Estimated cost
$0.05
Wall time
10s
Human step-ins
0
Outcome
Pass

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Summary

Exact prompt

# Apportion the Q3 service charge across tenants Inputs: `costs.csv` (the building's Q3 2026 costs), `units.csv` (every unit and its floor area), `leases.csv` (leases, with start and end dates and optional caps) and `apportionment.json`. Work out each lease's service charge for the quarter. - Only recoverable costs go into the pool: leave out every category listed in `non_recoverable_categories` (match ignoring letter case). - Tenant share = pool x (unit area x days the lease was in force in the quarter) / (total area of all units x days in the quarter). - A lease is in force from its start date to its end date, both days included; a blank end date means it continues. - If a lease has a `cap_per_quarter`, the tenant pays the lower of its share and the cap. - The landlord bears vacant space and anything above a cap: landlord_share = pool minus the sum of the rounded tenant charges. - Round each charge to cents half-up only at the end. Write `out/service-charges.json`: `{"recoverable_total": <pool>, "charges": {"<lease_id>": <charge>, ... every lease in force for at least one day of the quarter}, "landlord_share": <amount>}`. ## 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.

Split a quarter's building costs across 9-13 units by floor area and days in occupation. Some cost categories are not recoverable (with inconsistent letter case), one unit changed tenant mid-quarter with a gap, one unit is vacant and its share stays with the landlord, and two leases carry caps that bind. Spreading the vacancy over tenants, charging full quarters, or including capital works each changes the charges. 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: recoverable_pool tenant_charges caps landlord_share

Setup notes: Batch 20 case v04-service-charge-apportionment (offline, synthetic inputs, seed 477731518). 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 2.18 (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: $0.048544. Score: 4/4. 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
$0.05
Wall time
10s
Human step-ins
0
Turns
3
Model usage
ModelInput tokOutput tokCost
AClaude Sonnet 5.5anthropic/claude-sonnet-5.5effort default (no --effort flag) · thinking on57,6531,335$0.05

Reproduce this run

  1. Use the use case prompt on the use case page.
  2. 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.
  3. It counts as a success only if it meets every success criterion: recoverable_pool tenant_charges caps landlord_share
  4. 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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Evidence log
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  "result": "I wrote `out/service-charges.json`. I haven't cross-checked the figures by hand beyond running the calculation.\n\n- **Recoverable pool:** 52,451.87. I left out marketing voids and Capital Works, matching the category names ignoring letter case.\n- **Landlord share:** 7,368.61. That covers the vacant unit U164, the gaps in U128 between its two leases, and the amounts above the two caps.\n- **Caps:** two leases hit their cap: L-2015 at 2,424.00 and L-2033 at 4,776.00.\n- **Quarter length:** 92 days (1 July to 30 September 2026).\n- **Part-quarter leases:** the two U128 leases are the only ones that weren't in force all quarter, and I counted both end dates as days in force. Granite Law's lease (L-2009) ends 4 August and Halcyon Travel's (L-2012) starts 19 August.\n\nCharges per lease:\n\n| Lease | Charge |\n|---|---|\n| L-2003 | 7,761.56 |\n| L-2006 | 2,545.94 |\n| L-2009 | 1,210.31 |\n| L-2012 | 1,486.95 |\n| L-2015 | 2,424.00 |\n| L-2018 | 4,844.42 |\n| L-2021 | 1,050.67 |\n| L-2024 | 5,505.02 |\n| L-2027 | 7,478.44 |\n| L-2030 | 5,999.95 |\n| L-2033 | 4,776.00 |\n\nAll eleven leases were in force for at least one day of the quarter, so all appear in the file.",
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