Claude Sonnet 5.5 (effort default (no --effort flag) · thinking on) on Implement a 10-rule config-file parser (quotes, continuations, interpolation, cycles) from a written spec
AClaude Sonnet 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-17 · by @bobsiopener
- Estimated cost
- $0.10
- Wall time
- 40s
- Human step-ins
- 0
- Outcome
- Pass
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Summary
Exact prompt
# Task: implement a config parser from a spec Implement `parse` and `getbool` in `rconf.py` exactly as described in `SPEC.md` (read every numbered rule; edge cases are graded). Python standard library only, no third-party packages. Keep the `RConfError(msg, line)` signature and set `.line` correctly. Write your own tests if you want. No network.
Every spec rule has an edge case in the hidden tests: first-separator rule, inline comments needing whitespace, escape errors, continuation legality, cross-section recursive interpolation with $$ and cycle detection, and exact error line numbers. 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: 1. All 14 hidden unittest cases pass against rconf.py (60 s timeout), covering every numbered rule in SPEC.md including RConfError.line values.
Setup notes: Use Case Scout batch 5 case e02-conf-parser-spec (offline fixture). Prepared with batch5/prepare.sh; hidden key/tests kept outside the agent's work dir. Prompt = TASK.md verbatim. Scored with the scout's scorer: `python score.py WORKDIR KEYDIR`. Tools: Read/Write/Edit/Glob/Grep/Bash, web disabled. Single run, no retries. Claude Code's own reported cost for claude-sonnet-5.5: $0.104971. Score: 14/14. 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
- $0.10
- Wall time
- 40s
- Human step-ins
- 0
- Turns
- 6
| Model | Input tok | Output tok | Cost |
|---|---|---|---|
| AClaude Sonnet 5.5anthropic/claude-sonnet-5.5effort default (no --effort flag) · thinking on | 84,609 | 5,182 | $0.10 |
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: 1. All 14 hidden unittest cases pass against rconf.py (60 s timeout), covering every numbered rule in SPEC.md including RConfError.line values.
- 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": 38865,
"stop_reason": "end_turn",
"session_id": "[REDACTED]",
"total_cost_usd": 0.1049706,
"usage": {
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"cache_creation_input_tokens": 11455,
"cache_read_input_tokens": 73146,
"output_tokens": 5182,
"output_tokens_details": {
"thinking_tokens": 1768
},
"server_tool_use": {
"web_search_requests": 0,
"web_fetch_requests": 0
},
"service_tier": "standard",
"cache_creation": {
"ephemeral_1h_input_tokens": 11455,
"ephemeral_5m_input_tokens": 0
},
"inference_geo": "global",
"iterations": [
{
"input_tokens": 2,
"output_tokens": 465,
"cache_read_input_tokens": 23443,
"cache_creation_input_tokens": 551,
"cache_creation": {
"ephemeral_5m_input_tokens": 0,
"ephemeral_1h_input_tokens": 551
},
"type": "message"
}
],
"speed": "standard",
"fallback_credit": null
},
"modelUsage": {
"claude-sonnet-5-5": {
"inputTokens": 8,
"outputTokens": 5182,
"cacheReadInputTokens": 73146,
"cacheCreationInputTokens": 11455,
"webSearchRequests": 0,
"costUSD": 0.1049706,
"contextWindow": 1000000,
"maxOutputTokens": 128000,
"thinkingTokens": 1768,
"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,
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"completed": 0,
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"killed": {
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"refused": {
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"by_type": {}
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"safety_stops": 0,
"is_error": false,
"num_turns": 6,
"subtype": "success",
"api_error_status": null,
"result": "I implemented `parse` and `getbool` in `rconf.py`. I checked them with one mixed sample file and eight malformed inputs, not a full test suite. In those runs, valid input resolved correctly: comments, quoting, `$$`, `${.top}`, cross-section references and continuations. Each malformed case raised `RConfError` with the line I expected.\n\nThe spec leaves several cases open. I chose as follows:\n- **`getbool` errors:** the config doesn't carry line numbers, so a non-boolean value raises `RConfError(..., 0)`. A missing section or key raises `KeyError`.\n- **Continuation lines:** a continuation after a quoted value is an error. Any indented line after a blank line, comment, section header or the start of the file is also an error. Inline comments are stripped from continuation text.\n- **Empty values with a continuation:** `a =` followed by ` b` gives `\" b\"`, because I appended with one space literally.\n- **Section names:** an empty section name (`[]`) is an error.\n- **Unterminated `${`:** it is kept as literal text rather than raising an error.\n- **Dotted references:** a `${a.b}` reference tries the whole text as a key in the current section first, then each split at a dot as section and key. So keys that contain dots work.\n- **Error line for multi-line values:** reference errors use the line of the key's last definition.\n\nI also strip a leading BOM from line 1.",
"ttft_ms": 1516,
"type": "result",
"duration_ms": 39246,
"uuid": "[REDACTED]",
"ttft_stream_ms": 1179,
"time_to_request_ms": 248,
"first_content_frame_ms": 1179,
"queued_turn_count": 0,
"result_index": 0
}
]