Claude Sonnet 5.5 (effort default (no --effort flag) · thinking on) on Bill a month of car park sessions with per-day caps across midnight, shop validations and a grace period

AClaude Sonnet 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: $0.06
Wall time: 12s
Human step-ins: 0
Outcome: Pass

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Exact prompt

# Bill a month of car park sessions Inputs: `sessions.csv` (every entry/exit recorded by the barrier in October 2026, with whether a shop validated the ticket) and `tariff.json`. Charge each session: - Each calendar day a session touches is charged separately: the tariff's price per started hour on that day, capped at the tariff's daily cap for that day. A day piece runs from entry (or midnight) to exit (or midnight); a piece of 0 minutes costs nothing. - A validated session gets its first `validation_free_hours` hours free: take them off the first day's piece before counting started hours (any free time left over does not move to the next day). - A session shorter than `grace_minutes` minutes from entry to exit is free. - A started hour is any part of an hour: 61 minutes is 2 started hours, 60 minutes is 1. Write `out/parking.json`: `{"charges": {"<session_id>": <amount>, ...}, "by_plate": {"<plate>": <total for that plate>, ...}, "total": <sum of all charges>}` with every session listed (free ones as 0). ## 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.

Charge every barrier session in a month of a pay-on-exit car park. Each calendar day a stay touches is priced by started hour and capped separately, a shop validation takes free hours off the first day only, and very short stays are free. One cap for a whole multi-day stay, rounding to the nearest hour or charging grace-period stays each change the bill. All amounts are whole multiples of the tariff, so no rounding is involved. 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: midnight_split validation grace started_hours

Setup notes: Batch 23 case y03-parking-garage-billing (offline, synthetic inputs, seed 1419635). 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 0.46 (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: $0.056907. 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: $0.06
Wall time: 12s
Human step-ins: 0
Turns: 5

Model usage
Model	Input tok	Output tok	Cost
AClaude Sonnet 5.5anthropic/claude-sonnet-5.5effort default (no --effort flag) · thinking on	98,950	1,265	$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: midnight_split validation grace started_hours
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

[
 {
  "duration_api_ms": 11070,
  "stop_reason": "end_turn",
  "session_id": "[REDACTED]",
  "total_cost_usd": 0.0569074,
  "usage": {
   "input_tokens": 10,
   "cache_creation_input_tokens": 8806,
   "cache_read_input_tokens": 90134,
   "output_tokens": 1265,
   "output_tokens_details": {
    "thinking_tokens": 82
   },
   "server_tool_use": {
    "web_search_requests": 0,
    "web_fetch_requests": 0
   },
   "service_tier": "standard",
   "cache_creation": {
    "ephemeral_1h_input_tokens": 8806,
    "ephemeral_5m_input_tokens": 0
   },
   "inference_geo": "global",
   "iterations": [
    {
     "input_tokens": 2,
     "output_tokens": 226,
     "cache_read_input_tokens": 20749,
     "cache_creation_input_tokens": 596,
     "cache_creation": {
      "ephemeral_5m_input_tokens": 0,
      "ephemeral_1h_input_tokens": 596
     },
     "type": "message"
    }
   ],
   "speed": "standard",
   "fallback_credit": null
  },
  "modelUsage": {
   "claude-sonnet-5-5": {
    "inputTokens": 10,
    "outputTokens": 1265,
    "cacheReadInputTokens": 90134,
    "cacheCreationInputTokens": 8806,
    "webSearchRequests": 0,
    "costUSD": 0.0569074,
    "contextWindow": 1000000,
    "maxOutputTokens": 128000,
    "thinkingTokens": 82,
    "canonicalModel": "claude-sonnet-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,
    "foreground": 0,
    "unset": 0
   },
   "started_in_background": 0,
   "max_depth": 0,
   "spawned_by_subagents": 0,
   "completed": 0,
   "failed": 0,
   "killed": {
    "parent": 0,
    "user": 0,
    "system": 0
   },
   "refused": {
    "depth_limit": 0,
    "concurrency_limit": 0,
    "budget": 0
   },
   "by_type": {}
  },
  "safety_stops": 0,
  "is_error": false,
  "num_turns": 5,
  "subtype": "success",
  "api_error_status": null,
  "result": "I wrote `out/parking.json` with a charge for all 27 sessions. The total is 368.80. I haven't hand-checked any individual charge, so the figures come straight from the script.\n\nEach plate's total is in `by_plate`. The three sessions shorter than 10 minutes (S75801, S75834 and S75848) are listed at 0.\n\nTwo things to know about how I applied the rules:\n- **Overlapping sessions:** AE65 TAM has two sessions on 19 October that overlap (S75425 and S75906). I charged each one separately, as the rules say nothing about merging them.\n- **Validation:** the free hours come off the first day's piece only, and nothing carries over to later days.",
  "ttft_ms": 1773,
  "type": "result",
  "duration_ms": 11498,
  "uuid": "[REDACTED]",
  "ttft_stream_ms": 979,
  "time_to_request_ms": 235,
  "first_content_frame_ms": 980,
  "queued_turn_count": 0,
  "result_index": 0
 }
]