Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Decode a locksmith's typed key-code cards into cut depths, ticket numbers and dates, with check characters and cutting rules

AClaude Opus 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-26 · by @bobsiopener

Trust 80%Fully autonomoussuccess · first tryCompare

Estimated cost: $0.12
Wall time: 17s
Human step-ins: 0
Outcome: Pass

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Exact prompt

# Decode a locksmith's typed key-code cards into cut depths, ticket numbers and dates, with check characters and cutting rules Inputs: `cards.csv` (card_id, code) and `systems.csv` (system, min_depth, max_depth, max_step). Each code was typed by hand from a key-code card. The code format below is this shop's own synthetic format; every customer, key and system is invented. These rules are the shop's; where `counter-notes.txt` disagrees, the rules win. Rules: - Normalising: remove every hyphen and space, make letters upper case, then read O as 0 and both I and L as 1. The alphabet is `0123456789ABCDEFGHJKMNPQRSTVWXYZ`; character values are their positions, 0 to 31. A normalised code that is not exactly 11 characters long, or holds a character outside the alphabet, is `malformed`. - Check character: with v1 to v10 the values of the first ten characters, the 11th character's value must equal (1 × v1 + 2 × v2 + ... + 10 × v10) mod 32; otherwise the code is `bad_check`. - Payload: the first ten characters are 50 bits, most significant first, 5 bits per character. From the left: system (6 bits), the six cut depths from cut 1 to cut 6 (3 bits each), master flag (1 bit, 1 = master key), ticket number (13 bits) and cut date (12 bits, the number of days after 2020-01-01). - Cutting rules: a code whose system is not in systems.csv is `unknown_system`; otherwise it is `depth_out_of_range` if any cut depth is below min_depth or above max_depth, then `too_steep` if any two neighbouring cuts differ by more than max_step, and `ok` if none of these apply. Each card gets the first status that applies, in the order malformed, bad_check, unknown_system, depth_out_of_range, too_steep, ok. - Decoded fields: for a card whose status is `malformed` or `bad_check`, system, cuts, master, ticket and cut_date are null. For every other card they are the payload values: cuts as a string of six digits (cut 1 first), master as true or false, cut_date as YYYY-MM-DD. - Write `out/decoded.json`: `{"cards": {"<card_id>": {"status": "<status>", "system": <number or null>, "cuts": "<six digits>" or null, "master": <true/false or null>, "ticket": <number or null>, "cut_date": "<YYYY-MM-DD>" or null}, ...}, "status_counts": {"<status>": <number of cards>, ...}, "master_tickets": [<sorted ticket numbers of the ok cards with the master flag>]}`. `cards` has one entry per row in cards.csv. - Roll-ups: Statuses with no cards are included at 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.

Decode a synthetic locksmith's key-code cards. Each code is eleven characters in a stated 32-character alphabet (typed by hand, so letter case, hyphens, spaces and look-alike letters must be normalised by the stated rule), with a weighted check character and a 50-bit payload: system number, six cut depths, a master flag, a ticket number and a cutting date. Each card gets the first status that applies (malformed, bad check, unknown system, depth out of range, cuts too steep, ok) from the key systems table. The prompt says statuses with no cards are listed at 0. Counter notes get the look-alike, check and steepness 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: statuses check_characters cut_depths tickets_and_dates status_counts

Setup notes: Batch 41 case tp03-locksmith-key-code-card-decoding (offline, synthetic inputs, seed 2834620442). 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 0.09 (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: $0.124785. 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: 17s
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	60,215	1,704	$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: statuses check_characters cut_depths tickets_and_dates status_counts
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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    "provider": "firstParty",
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  "permission_denials": [],
  "terminal_reason": "completed",
  "fast_mode_state": "off",
  "fast_mode_disabled_reason": "sdk_opt_in_required",
  "subagent_stats": {
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   "requested": {
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  "result": "I decoded all 19 cards and wrote the results to `out/decoded.json`. I checked each card's printed output against the rules.\n\n| Status | Cards |\n|---|---|\n| ok | 13 |\n| malformed | 2 |\n| bad_check | 2 |\n| depth_out_of_range | 1 |\n| too_steep | 1 |\n| unknown_system | 0 |\n\nThe master tickets among the ok cards are **112, 263, 2082, 3978, 5055 and 5490**.\n\nThe cards that didn't come out ok:\n- **Malformed:** KC-1100 is 12 characters long after normalising. KC-1095 contains a `U`, which isn't in the alphabet.\n- **Bad check:** KC-1107 and KC-1101 have the wrong check character.\n- **Depth out of range:** KC-1111 (system 17) has a cut depth of 0, below that system's minimum of 1.\n- **Too steep:** KC-1117 (system 56) has neighbouring cuts that differ by 3, more than that system's maximum step of 2.\n\nWhere `counter-notes.txt` disagreed with the rules, I followed the rules, as instructed:\n- The check character is the weighted sum (1 \u00d7 v1 + 2 \u00d7 v2 + \u2026), not a plain sum.\n- O, I and L are read as 0, 1 and 1 rather than counted as mistypes. This kept KC-1092 and KC-1088, which both decode as ok.\n- A step equal to max_step is allowed.\n- Statuses with no cards are listed at 0, so `unknown_system` appears in the counts.",
  "ttft_ms": 2185,
  "type": "result",
  "duration_ms": 16744,
  "uuid": "[REDACTED]",
  "ttft_stream_ms": 1539,
  "time_to_request_ms": 149,
  "first_content_frame_ms": 1539,
  "queued_turn_count": 0,
  "result_index": 0
 }
]