GPT-6.1 Sol (effort default (no reasoning-effort override) · thinking on) on AIS decoder: NMEA tag blocks, multipart reassembly and bit-level fields
OGPT-6.1 Soldefault · thinking on · Codex CLI 0.163.0 (codex exec --json) · cloud · 2026-10-22 · by @bobsiopener
- Estimated cost
- $0.06
- Wall time
- 56s
- Human step-ins
- 0
- Outcome
- Pass
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Summary
Exact prompt
# AIS message decoder (NMEA 0183 AIVDM/AIVDO with tag blocks) `input.json` names `ais.log`, a synthetic receiver log. Write `solve.py` (Python 3 standard library only); `python solve.py input.json answer.json`. Fresh logs are generated. The full grammar is below; nothing else is needed. ## Line grammar - Lines are numbered from 0 (every physical line counts, including blank ones); blank lines are skipped. - Optional **tag block** prefix: `\<tag>*hh\` before the sentence. `hh` = XOR of all characters of `<tag>`, two hex digits. No closing `\`, or a wrong checksum -> error `bad_tag_block` (line dropped). `<tag>` is comma-separated `key:value`; `c:<integer>` is a UNIX time. - **Time**: each line that reaches the sentence stage sets the current time to its valid tag block's `c:` value, or to null if it has none. A decoded message's `time` is the current time at the line that completed it. - Sentence `!AIVDM,...` or `!AIVDO,...` (anything else -> `not_ais`). Checksum: XOR of characters between `!` and `*`, two hex digits, either case; wrong or missing -> `bad_checksum`. It must have exactly 7 comma fields: talker+type, fragment count, fragment number, sequential id (may be empty), channel, payload, fill bits; non-integer count/number/fill, or not 1 <= number <= count <= 9, or fill not in 0..5 -> `bad_fields`. - **Multipart** (count > 1), keyed by (sequential id, channel): fragment 1 starts a new message (if one was already open under that key, count `incomplete_multipart` and replace it). Fragment n > 1 must match an open message with the same count that has exactly n-1 parts; otherwise count `orphan_fragment` (and, if a message was open under that key, drop it and also count `incomplete_multipart`). Messages still open at the end of the file count `incomplete_multipart`. Only the last fragment's fill bits are used. - **Armoring**: each payload character c gives v = ord(c) - 48, minus 8 more if that is > 40; valid characters are `0`-`W` and `` ` ``-`w` only (else `bad_payload_char`). Concatenate 6-bit values (MSB first), then drop `fill` bits from the end. ## Messages (bit offsets, length; U = unsigned, I = two's-complement signed; MSB first) - All: type 0,6 U; MMSI 8,30 U. - Types 1, 2, 3 (need >= 168 bits, else `short_message`): status 38,4 U; rot_raw 42,8 I; SOG 50,10 U (0.1 kn; 1023 = null); lon 61,28 I and lat 89,27 I in 1/10000 minute (= /600000 degrees, round to 6 decimals; lon 181° and lat 91° = null); COG 116,12 U (0.1°, 3600 = null); heading 128,9 U (511 = null); second 137,6 U. - Type 18 (>= 168 bits): SOG 46,10; lon 57,28 I; lat 85,27 I; COG 112,12; heading 124,9; second 133,6 (same scaling and nulls). - Type 5 (>= 420 bits): IMO 40,30 U; callsign 70,42 (7 chars); name 112,120 (20 chars); ship_type 232,8; length = to_bow 240,9 + to_stern 249,9; beam = to_port 258,6 + to_starboard 264,6; draught 294,8 (/10, metres); destination 302,120 (20 chars). Text: 6-bit value indexes `@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_ !"#$%&'()*+,-./0123456789:;<=>?`; strip trailing `@` then trailing spaces. - Any other type -> `unsupported_type`. ## answer.json - `messages`: decoded messages in completion order. Each has `type`, `mmsi`, the fields above (keys `status`, `rot_raw`, `sog`, `lon`, `lat`, `cog`, `heading`, `second`; type 5: `imo`, `callsign`, `name`, `ship_type`, `length`, `beam`, `draught`, `destination`), plus `line` (the completing line), `time`, and `own` (true for `AIVDO`). - `errors`: {kind: count}, only kinds with a count above 0. - `vessels`: {mmsi as a string (sorted numerically): {"positions": number of type 1/2/3/18 messages, then from the latest such message with non-null lat and lon: "last_lat", "last_lon", "last_time"; "last_sog" from the latest position message with non-null SOG; type 5 fields (latest): "name", "callsign", "imo", "ship_type", "length", "beam", "draught", "destination"}} (keys present only if known). ## Scoring Hidden checks (partial credit; all must pass; floats within 1e-6): `checksums_and_framing` (bad_checksum, not_ais, bad_fields, bad_tag_block counts), `class_a_positions`, `class_b_positions`, `static_voyage_multipart`, `tag_block_times_and_own`, `all_error_counts`, `vessel_summary` on the given log; `fresh_run_1`, `fresh_run_2` (everything). 30-second limit per run.
Every rule is stated, but errors compound: a wrong armor offset or signedness breaks every position; mishandled fragment state shifts message order and counts. Original benchmark task written for usecaserank.com. Headless, offline run on a reproducible fixture. Cost shown is a list-price API-equivalent estimate (run on a ChatGPT subscription, not billed). Rescore note (Oct 22, 2026): Re-scored from the saved work tree (verified file-by-file against the pre-audit SHA-256 manifest after a documented answer-key fault was fixed; measured fields unchanged. Original 5/9 result and scorer log kept beside this file.
Success criteria: 1. checksums_and_framing 2. class_a_positions 3. class_b_positions 4. static_voyage_multipart 5. tag_block_times_and_own 6. all_error_counts 7. vessel_summary 8. fresh_run_1 9. fresh_run_2
Setup notes: Use Case Scout batch12 case m04-ais-decoder (offline fixture). Prepared with batch12/prepare.sh on the shared box; only TASK.md + starting files were copied to the agent machine, hidden key/tests stayed on the box. Prompt = TASK.md verbatim on stdin. Flags: --json -s workspace-write --skip-git-repo-check --ephemeral --ignore-user-config --ignore-rules -C <workdir>. Scored on the box with the scout's scorer: `python score.py WORKDIR KEYDIR`. Single run, no retries. User-level AGENTS.md (846 bytes, sha256 83ec4fe50da8) may have been in context; --ignore-user-config does not document excluding it. Serving model not confirmed: requested via -m; the event log does not echo the serving model id. Price source is secondary (pricing.json verification='secondary', https://www.actuia.com/en/news/ai-api-pricing-in-october-2026-050-to-50-for-output/), not an official OpenAI price page. Score: 9/9. Cost is an ESTIMATE: measured tokens x pricing.json list price (ChatGPT plan, nothing billed); input_tokens include cached reads; output_tokens include reasoning tokens. Tool calls 4 (1 failed, recovered). Single run.
Estimated cost List-price estimate; not actually billed.
Metrics
- Estimated cost
- $0.06
- Wall time
- 56s
- Human step-ins
- 0
- Turns
- 1
| Model | Input tok | Output tok | Cost |
|---|---|---|---|
| OGPT-6.1 Solopenai/gpt-6.1-soleffort default (no reasoning-effort override) · thinking on | 85,840 | 2,163 | $0.06 |
Reproduce this run
- Use the use case prompt on the use case page.
- Same setup: GPT-6.1 Sol (openai/gpt-6.1-sol, effort default (no reasoning-effort override) · thinking on) via
Codex CLI 0.163.0 (codex exec --json), cloud. - It counts as a success only if it meets every success criterion: 1. checksums_and_framing 2. class_a_positions 3. class_b_positions 4. static_voyage_multipart 5. tag_block_times_and_own 6. all_error_counts 7. vessel_summary 8. fresh_run_1 9. fresh_run_2
- 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
{"type": "thread.started", "thread_id": "01a16407-35f2-7bf1-91c3-bd2e15506251"}
{"type": "turn.started"}
{"type": "item.completed", "item": {"id": "item_0", "type": "agent_message", "text": "I\u2019ll inspect the input file, then implement the decoder and check it against the supplied log."}}
{"type": "item.started", "item": {"id": "item_1", "type": "command_execution", "command": "/bin/bash -lc \"pwd && rg --files -g '\"'!'\"\\\\.git'\"", "aggregated_output": "", "exit_code": null, "status": "in_progress"}}
{"type": "item.completed", "item": {"id": "item_1", "type": "command_execution", "command": "/bin/bash -lc \"pwd && rg --files -g '\"'!'\"\\\\.git'\"", "aggregated_output": "/home/bob/usecase-runs/batch/out/gpt-6.1-sol/123_m04/work\ninput.json\nais.log\nTASK.md\n", "exit_code": 0, "status": "completed"}}
{"type": "item.started", "item": {"id": "item_2", "type": "command_execution", "command": "/bin/bash -lc 'cat input.json && head -n 8 ais.log'", "aggregated_output": "", "exit_code": null, "status": "in_progress"}}
{"type": "item.completed", "item": {"id": "item_2", "type": "command_execution", "command": "/bin/bash -lc 'cat input.json && head -n 8 ais.log'", "aggregated_output": "{\"log\": \"ais.log\"}!AIVDM,1,1,,A,34q?ljnwP7:WEkjGGU62iSfv0000,0*45\n!AIVDM,2,1,1,A,54diL2P0wKIT?KWC?L0d50U@4r3L00000000000T<@A1<61?S63QEp6ClRh0,0*04\n!AIVDM,2,2,1,A,00000000000,2*25\n!AIVDM,1,1,,A,15NKmnnB0MXB2l5dKhNf4?vj0000,0*7C\n!AIVDM,1,1,,A,14O4kdQ832<tSF0l4Q@4,0*2F\n!AIVDM,1,1,,A,15NKmnkgQ<;WG?rAO=PI,0*09\n!AIVDM,1,1,,B,14diL2SThPLMqAQiqm2iFl?j0000,0*5d\n!AIVDM,2,1,2,A,54O4kdP0BJw0?SOKWD08iDF0PE8tp0000000000NEhc=;74?>5CQEp6ClRh0,0*49\n", "exit_code": 0, "status": "completed"}}
{"type": "item.started", "item": {"id": "item_3", "type": "command_execution", "command": "/bin/bash -lc \"cat > solve.py <<'PY'\nimport json\nimport sys\nfrom pathlib import Path\nfrom collections import Counter\n\nTEXT = '@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\\\\\\\]\"'^_ !\"#$%&'\"\\\\'()*+,-./0123456789:;<=>?'\n\n\ndef checksum(body):\n value = 0\n for char in body:\n value \"'^= ord(char)\n return value\n\n\ndef checked(text):\n if '\"'*' not in text:\n return None\n body, tail = text.rsplit('*', 1)\n if len(tail) \"'!= 2 or any(c not in '\"'0123456789abcdefABCDEF' for c in tail):\n return None\n return body if checksum(body) == int(tail, 16) else None\n\n\ndef solve(config_path, output_path):\n config_path = Path(config_path)\n config = json.loads(config_path.read_text())\n log_path = Path(config['log'])\n if not log_path.is_absolute():\n log_path = config_path.parent / log_path\n errors = Counter()\n messages = []\n opened = {}\n vessels = {}\n\n def decode(payload, fill, line, time, own):\n if any(not ('0' <= c <= 'W' or '\"'`'\"' <= c <= 'w') for c in payload):\n errors['bad_payload_char'] += 1\n return\n bits = ''.join(format(ord(c) - 48 - (8 if ord(c) - 48 > 40 else 0), '06b') for c in payload)\n if fill:\n bits = bits[:-fill]\n def u(start, size):\n return int(bits[start:start + size], 2)\n def signed(start, size):\n value = u(start, size)\n return value - (1 << size) if value & (1 << (size - 1)) else value\n def txt(start, size):\n return ''.join(TEXT[u(i, 6)] for i in range(start, start + size, 6)).rstrip('@').rstrip(' ')\n if len(bits) < 6:\n errors['short_message'] += 1\n return\n kind = u(0, 6)\n if kind not in (1, 2, 3, 5, 18):\n errors['unsupported_type'] += 1\n return\n if len(bits) < (420 if kind == 5 else 168):\n errors['short_message'] += 1\n return\n msg = {'type': kind, 'mmsi': u(8, 30)}\n if kind == 5:\n msg.update(imo=u(40, 30), callsign=txt(70, 42), name=txt(112, 120),\n ship_type=u(232, 8), length=u(240, 9) + u(249, 9),\n beam=u(258, 6) + u(264, 6), draught=u(294, 8) / 10,\n destination=txt(302, 120))\n else:\n if kind == 18:\n sog, lon, lat, cog, heading, second = 46, 57, 85, 112, 124, 133\n else:\n msg.update(status=u(38, 4), rot_raw=signed(42, 8))\n sog, lon, lat, cog, heading, second = 50, 61, 89, 116, 128, 137\n speed, longitude, latitude = u(sog, 10), signed(lon, 28), signed(lat, 27)\n course, head = u(cog, 12), u(heading, 9)\n msg.update(sog=None if speed == 1023 else speed / 10,\n lon=None if longitude == 181 * 600000 else round(longitude / 600000, 6),\n lat=None if latitude == 91 * 600000 else round(latitude / 600000, 6),\n cog=None if course == 3600 else course / 10,\n heading=None if head == 511 else head, second=u(second, 6))\n msg.update(line=line, time=time, own=own)\n messages.append(msg)\n vessel = vessels.setdefault(str(msg['mmsi']), {'positions': 0})\n if kind == 5:\n for key in ('name', 'callsign', 'imo', 'ship_type', 'length', 'beam', 'draught', 'destination'):\n vessel[key] = msg[key]\n else:\n vessel['positions'] += 1\n if msg['lat'] is not None and msg['lon'] is not None:\n vessel.update(last_lat=msg['lat'], last_lon=msg['lon'], last_time=time)\n if msg['sog'] is not None:\n vessel['last_sog'] = msg['sog']\n\n with log_path.open() as source:\n for line_number, raw in enumerate(source):\n sentence = raw.strip()\n if not sentence:\n continue\n time = None\n if sentence.startswith('\\\\\\\\'):\n end = sentence.find('\\\\\\\\', 1)\n tag = checked(sentence[1:end]) if end \"'!= -1 else None\n if tag is None:\n errors['\"'bad_tag_block'] += 1\n continue\n for field in tag.split(','):\n if field.startswith('c:'):\n try:\n time = int(field[2:])\n except ValueError:\n pass\n sentence = sentence[end + 1:]\n if sentence.split(',', 1)[0] not in ('\"'!AIVDM'\"', '\"'!AIVDO'\"'):\n errors['not_ais'] += 1\n continue\n body = checked(sentence[1:])\n if body is None:\n errors['bad_checksum'] += 1\n continue\n fields = body.split(',')\n try:\n if len(fields) \"'!= 7:\n raise ValueError\n talker, count, number, seq, channel, payload, fill = fields\n count, number, fill = int(count), int(number), int(fill)\n if not (1 <= number <= count <= 9 and 0 <= fill <= 5):\n raise ValueError\n except ValueError:\n errors['\"'bad_fields'] += 1\n continue\n if count == 1:\n decode(payload, fill, line_number, time, talker == 'AIVDO')\n continue\n key = (seq, channel)\n if number == 1:\n if key in opened:\n errors['incomplete_multipart'] += 1\n opened[key] = (count, [payload])\n else:\n pending = opened.get(key)\n if pending is None or pending[0] \"'!= count or len(pending[1]) != number - 1:\n errors['\"'orphan_fragment'] += 1\n if key in opened:\n del opened[key]\n errors['incomplete_multipart'] += 1\n continue\n pending[1].append(payload)\n if number == count:\n del opened[key]\n decode(''.join(pending[1]), fill, line_number, time, talker == 'AIVDO')\n errors['incomplete_multipart'] += len(opened)\n result = {'messages': messages, 'errors': {k: v for k, v in errors.items() if v},\n 'vessels': {k: vessels[k] for k in sorted(vessels, key=int)}}\n Path(output_path).write_text(json.dumps(result, indent=2) + '\\\\n')\n\n\nif __name__ == '__main__':\n solve(sys.argv[1], sys.argv[2])\nPY\npython solve.py input.json answer.json\npython -c \\\"import json; d=json.load(open('answer.json')); print(len(d['messages']), 'messages;', len(d['vessels']), 'vessels'); print(d['errors'])\\\"\"", "aggregated_output": "", "exit_code": null, "status": "in_progress"}}
{"type": "item.completed", "item": {"id": "item_3", "type": "command_execution", "command": "/bin/bash -lc \"cat > solve.py <<'PY'\nimport json\nimport sys\nfrom pathlib import Path\nfrom collections import Counter\n\nTEXT = '@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\\\\\\\]\"'^_ !\"#$%&'\"\\\\'()*+,-./0123456789:;<=>?'\n\n\ndef checksum(body):\n value = 0\n for char in body:\n value \"'^= ord(char)\n return value\n\n\ndef checked(text):\n if '\"'*' not in text:\n return None\n body, tail = text.rsplit('*', 1)\n if len(tail) \"'!= 2 or any(c not in '\"'0123456789abcdefABCDEF' for c in tail):\n return None\n return body if checksum(body) == int(tail, 16) else None\n\n\ndef solve(config_path, output_path):\n config_path = Path(config_path)\n config = json.loads(config_path.read_text())\n log_path = Path(config['log'])\n if not log_path.is_absolute():\n log_path = config_path.parent / log_path\n errors = Counter()\n messages = []\n opened = {}\n vessels = {}\n\n def decode(payload, fill, line, time, own):\n if any(not ('0' <= c <= 'W' or '\"'`'\"' <= c <= 'w') for c in payload):\n errors['bad_payload_char'] += 1\n return\n bits = ''.join(format(ord(c) - 48 - (8 if ord(c) - 48 > 40 else 0), '06b') for c in payload)\n if fill:\n bits = bits[:-fill]\n def u(start, size):\n return int(bits[start:start + size], 2)\n def signed(start, size):\n value = u(start, size)\n return value - (1 << size) if value & (1 << (size - 1)) else value\n def txt(start, size):\n return ''.join(TEXT[u(i, 6)] for i in range(start, start + size, 6)).rstrip('@').rstrip(' ')\n if len(bits) < 6:\n errors['short_message'] += 1\n return\n kind = u(0, 6)\n if kind not in (1, 2, 3, 5, 18):\n errors['unsupported_type'] += 1\n return\n if len(bits) < (420 if kind == 5 else 168):\n errors['short_message'] += 1\n return\n msg = {'type': kind, 'mmsi': u(8, 30)}\n if kind == 5:\n msg.update(imo=u(40, 30), callsign=txt(70, 42), name=txt(112, 120),\n ship_type=u(232, 8), length=u(240, 9) + u(249, 9),\n beam=u(258, 6) + u(264, 6), draught=u(294, 8) / 10,\n destination=txt(302, 120))\n else:\n if kind == 18:\n sog, lon, lat, cog, heading, second = 46, 57, 85, 112, 124, 133\n else:\n msg.update(status=u(38, 4), rot_raw=signed(42, 8))\n sog, lon, lat, cog, heading, second = 50, 61, 89, 116, 128, 137\n speed, longitude, latitude = u(sog, 10), signed(lon, 28), signed(lat, 27)\n course, head = u(cog, 12), u(heading, 9)\n msg.update(sog=None if speed == 1023 else speed / 10,\n lon=None if longitude == 181 * 600000 else round(longitude / 600000, 6),\n lat=None if latitude == 91 * 600000 else round(latitude / 600000, 6),\n cog=None if course == 3600 else course / 10,\n heading=None if head == 511 else head, second=u(second, 6))\n msg.update(line=line, time=time, own=own)\n messages.append(msg)\n vessel = vessels.setdefault(str(msg['mmsi']), {'positions': 0})\n if kind == 5:\n for key in ('name', 'callsign', 'imo', 'ship_type', 'length', 'beam', 'draught', 'destination'):\n vessel[key] = msg[key]\n else:\n vessel['positions'] += 1\n if msg['lat'] is not None and msg['lon'] is not None:\n vessel.update(last_lat=msg['lat'], last_lon=msg['lon'], last_time=time)\n if msg['sog'] is not None:\n vessel['last_sog'] = msg['sog']\n\n with log_path.open() as source:\n for line_number, raw in enumerate(source):\n sentence = raw.strip()\n if not sentence:\n continue\n time = None\n if sentence.startswith('\\\\\\\\'):\n end = sentence.find('\\\\\\\\', 1)\n tag = checked(sentence[1:end]) if end \"'!= -1 else None\n if tag is None:\n errors['\"'bad_tag_block'] += 1\n continue\n for field in tag.split(','):\n if field.startswith('c:'):\n try:\n time = int(field[2:])\n except ValueError:\n pass\n sentence = sentence[end + 1:]\n if sentence.split(',', 1)[0] not in ('\"'!AIVDM'\"', '\"'!AIVDO'\"'):\n errors['not_ais'] += 1\n continue\n body = checked(sentence[1:])\n if body is None:\n errors['bad_checksum'] += 1\n continue\n fields = body.split(',')\n try:\n if len(fields) \"'!= 7:\n raise ValueError\n talker, count, number, seq, channel, payload, fill = fields\n count, number, fill = int(count), int(number), int(fill)\n if not (1 <= number <= count <= 9 and 0 <= fill <= 5):\n raise ValueError\n except ValueError:\n errors['\"'bad_fields'] += 1\n continue\n if count == 1:\n decode(payload, fill, line_number, time, talker == 'AIVDO')\n continue\n key = (seq, channel)\n if number == 1:\n if key in opened:\n errors['incomplete_multipart'] += 1\n opened[key] = (count, [payload])\n else:\n pending = opened.get(key)\n if pending is None or pending[0] \"'!= count or len(pending[1]) != number - 1:\n errors['\"'orphan_fragment'] += 1\n if key in opened:\n del opened[key]\n errors['incomplete_multipart'] += 1\n continue\n pending[1].append(payload)\n if number == count:\n del opened[key]\n decode(''.join(pending[1]), fill, line_number, time, talker == 'AIVDO')\n errors['incomplete_multipart'] += len(opened)\n result = {'messages': messages, 'errors': {k: v for k, v in errors.items() if v},\n 'vessels': {k: vessels[k] for k in sorted(vessels, key=int)}}\n Path(output_path).write_text(json.dumps(result, indent=2) + '\\\\n')\n\n\nif __name__ == '__main__':\n solve(sys.argv[1], sys.argv[2])\nPY\npython solve.py input.json answer.json\npython -c \\\"import json; d=json.load(open('answer.json')); print(len(d['messages']), 'messages;', len(d['vessels']), 'vessels'); print(d['errors'])\\\"\"", "aggregated_output": "/bin/bash: line 159: python: command not found\n/bin/bash: line 160: python: command not found\n", "exit_code": 127, "status": "failed"}}
{"type": "item.started", "item": {"id": "item_4", "type": "command_execution", "command": "/bin/bash -lc \"python3 solve.py input.json answer.json\npython3 -c \\\"import json; d=json.load(open('answer.json')); print(len(d['messages']), 'messages;', len(d['vessels']), 'vessels'); print(d['errors'])\\\"\"", "aggregated_output": "", "exit_code": null, "status": "in_progress"}}
{"type": "item.completed", "item": {"id": "item_4", "type": "command_execution", "command": "/bin/bash -lc \"python3 solve.py input.json answer.json\npython3 -c \\\"import json; d=json.load(open('answer.json')); print(len(d['messages']), 'messages;', len(d['vessels']), 'vessels'); print(d['errors'])\\\"\"", "aggregated_output": "111 messages; 7 vessels\n{'bad_payload_char': 7, 'short_message': 7, 'unsupported_type': 4, 'not_ais': 5, 'bad_checksum': 12, 'bad_fields': 6, 'incomplete_multipart': 2, 'bad_tag_block': 3, 'orphan_fragment': 3}\n", "exit_code": 0, "status": "completed"}}
{"type": "item.completed", "item": {"id": "item_5", "type": "agent_message", "text": "Implemented [solve.py](solve.py) and generated [answer.json](answer.json).\n\nVerified with `python3 solve.py input.json answer.json`: decoded 111 messages across 7 vessels. This environment provides `python3`; `python` is unavailable."}}
{"type": "turn.completed", "usage": {"input_tokens": 85840, "cached_input_tokens": 72704, "cache_write_input_tokens": 0, "output_tokens": 2163, "reasoning_output_tokens": 51}}