{
 "measurement": "Does starting a fresh session for each task cost less than keeping one session going, and does either beat just asking once",
 "claude_code_version": "2.1.228 measured, re-verified on 2.1.229",
 "claim_under_test": "Claude Code's own cost documentation, under 'Manage context proactively': \"Clear between tasks: Use /clear to start fresh when switching to unrelated work. Stale context wastes tokens on every subsequent message.\" And under 'When a developer asks about a limit': unexpectedly high spend \"usually traces back to long sessions that were never cleared\", with \"clearing between unrelated tasks\" named as one of the two highest-impact habits.",
 "scope_warning": "The documented advice is scoped to work that is UNRELATED between tasks. The three steps measured here are RELATED: each builds on the last, and the third calls the first two. So this corpus does NOT test the documented advice on its own terms. It tests the unscoped version that circulates as 'one session per task', applied to related steps, which is the case where the advice's own mechanism should fail.",
 "method": {
  "arms": "ONE_PROMPT is a single call carrying all three requirements. ONE_SESSION is three calls, one requirement each, in the SAME session via --resume. FRESH_SESSION is three calls, one requirement each, each in a NEW session. An arm's cost is the SUM of its calls, because that is what the user pays. The requirement text is byte-identical across arms; ONE_PROMPT concatenates the same three strings.",
  "task": "Add parse_duration, then format_duration, then round_trip_ok to a module. The third depends on the first two, deliberately: that is where a fresh session has to rediscover what it just built.",
  "success": "objective, a hidden pytest suite covering all three requirements must exit 0. The suite is written AFTER the model calls from a constant, so the model cannot see or edit it; its sha256 is published.",
  "controls": {
   "session_identity": "The treatment is proven to have ARRIVED, per run, from the session_id the CLI returns. ONE_SESSION requires all three calls to report the SAME id; FRESH_SESSION requires three DISTINCT ids. Recorded per run as distinct_session_ids and passing on every run in the corpus.",
   "fixture_discriminates": "Three-way, before any model call: the empty module FAILS, a minutes-only implementation FAILS, a reference implementation PASSES.",
   "permissions": "--allowedTools Bash on every call in every arm, asserted onto the command line. See bash_usage below for what that proved and what it did not.",
   "action_record": "--output-format stream-json, so every tool call is captured by name and order.",
   "isolation": "--setting-sources project on every invocation, asserted.",
   "tokens": "modelUsage, not .usage."
  },
  "bash_usage": "69 of 70 calls recorded at least one Bash tool use. The single exception (fresh_session batch1 round 2, step roundtrip) is a model choice, not a denial: it used Read and Edit, replied DONE, and its run passed the suite. Zero of the 70 replies in this corpus contain denial wording. That run is KEPT and scored, which is the conservative direction: it is the cheapest fresh_session run in the corpus, so dropping it would make the fresh arm look worse, not better.",
  "redaction": "Replies are stored with every path-shaped token reduced to its basename, or to <redacted-local-path> where the basename itself was identifying, and truncated to 600 characters. Tool-call arguments over 400 characters have their paths elided. The tool NAME and the ORDER are complete for every call. No measured value is altered by any of this.",
  "known_limits": {
   "first_call_is_bimodal": "Every first call landed in one of two groups, cheap or about 22,800 tokens dearer, with nothing between them. It is NOT an unexplained execution mode: the first tool of the first call predicts the group in 30 of 30 runs. Every dearer first call opens with a speculative Bash before reading anything (5 turns, 17 runs); every cheap one goes straight to Read (4 turns, 13 runs). The gap is 22,791 / 22,729 / 22,943 tokens across the three arms against a fitted 23,116 tokens per turn, i.e. exactly one extra turn at the ordinary rate. Group means differ by arm: one_prompt 92,445 and 115,236, one_session 90,386 and 113,115, fresh_session 90,358 and 113,301. one_prompt sits about 2,000 higher in both groups because its single prompt carries all three requirement strings. Its pooled median of 103,828 is therefore a value no run took. Ratios inside each group: one_session 2.84x (cheap, n=5) and 2.49x (dear, n=5); fresh_session 3.72x (n=3) and 2.99x (n=7). Conditioning on the FIRST call does not remove the effect, only part of it, because every call draws its own turn count: it cuts the one_session total spread from 79,269 to about 54,000 and fresh_session's from 69,536 to about 47,000, and inside the cheap group fresh_session's third call still ranges 68,584 to 115,598. Treat 3.72x as the thinnest cell.",
   "the_per_step_decline_is_not_monotone": "Within a run, one_session's step 3 is cheaper than its own step 1 in 10 of 10 (median -25,312). But step 2 against step 1 is only 5 of 10 (median -5,244), i.e. no direction. The tool records line up with that: the resumed arm re-read the file in 5 of 10 runs at step 2 and 0 of 10 at step 3. So the claim supported is that the resumed session ENDS cheaper than it started, not that each step is cheaper than the previous one.",
   "dollars_are_weaker_than_tokens": "one_session vs fresh_session paired: tokens, turns, tool calls and wall are all 10 of 10 (sign p=0.0010), but dollars are 8 of 10 (p=0.0547), which does not clear 0.05. On totals the two arms OVERLAP: cheapest fresh 297,798 against dearest resumed 314,404. The comparison is only meaningful paired by round.",
   "scope_is_the_biggest_limit": "See scope_warning above. The documented advice concerns UNRELATED tasks and this corpus measures RELATED steps, so nothing here contradicts the documentation on its own terms. The corpus also cannot say where the effect crosses zero as steps become more independent, which is the number a reader would most want.",
   "turn_count_explains_almost_everything": "A least-squares fit over all 30 runs of total_context against total_turns gives tokens = 2,025 + 23,116 per turn, R2 = 0.9972. Slope 95% CI [22,653, 23,578]; intercept 95% CI [-3,176, 7,226], which includes zero, so no fixed per-run cost is measurable beyond the turns. The single line predicts each arm's mean within 2.6% (one_prompt 106,046 vs 103,840; one_session 267,856 vs 274,984; fresh_session 348,761 vs 343,837). This is a fit over this corpus on one task, not a general rate card: the per-turn figure will move with how much context each turn carries."
  }
 },
 "fixture_control": {
  "empty_module": {
   "passes": false,
   "tail": "!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!\n1 error in 0.09s\n"
  },
  "minutes_only": {
   "passes": false,
   "tail": "st_durations.py::test_round_trip - ValueError: invalid literal for i...\n3 failed in 0.04s\n"
  },
  "reference": {
   "passes": true,
   "tail": "                                                                 [100%]\n3 passed in 0.01s\n"
  }
 },
 "tests_sha256": "a60a1bbfc5f3c63b76752f0ba1355098f3cb5cd562912f539bf87d08267f9908",
 "runs": [
  {
   "arm": "one_prompt",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 92576,
     "cache_creation": 7987,
     "cache_read": 83872,
     "fresh_input": 717,
     "output": 1733,
     "turns": 4,
     "cost": 0.1656,
     "session_id": "81fb24b9-3f03-4430-bb78-c64c9521758d",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\nfor s in ['1h30m','45s','2h','1h','1h0m30s','90m','','5x','1m2h','0s']:\n    try:\n        p = parse_duration(s)\n    except ValueError as e:\n        print(repr(s), 'ValueError', round_trip_ok(s)); continue\n    print(repr(s), p, format_duration(p), round_trip_ok(s))\nfor n in [0,45,5400,3600,3661,59,60]:\n    print(n, for <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "All three functions are in `durations.py` and verified: `parse_duration` (rejects unknown units with `ValueError`), `format_duration` (omits zero units, `0` \u2192 `'0s'`), and `round_trip_ok` (returns `False` rather than raising on invalid input).\n\nDONE"
    }
   ],
   "total_context": 92576,
   "total_cache_creation": 7987,
   "total_cache_read": 83872,
   "total_output": 1733,
   "total_turns": 4,
   "total_tool_calls": 3,
   "total_cost": 0.1656,
   "wall": 28.0,
   "durations_py_lines": 46,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 112882,
     "cache_creation": 7190,
     "cache_read": 105104,
     "fresh_input": 588,
     "output": 1110,
     "turns": 5,
     "cost": 0.15247,
     "session_id": "b67a34a5-0de4-40fe-a950-48453f30ea5f",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls one_session_0"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h','5m','1h2m3s','0s']:\n    print(repr(s), parse_duration(s))\nfor bad in ['','30','1m30h','abc','1h 30m']:\n    try:\n        parse_duration(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('raised:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:8`, verified against the examples plus invalid inputs (out-of-order units and bare numbers raise `ValueError`)."
    },
    {
     "step": "format",
     "context": 71780,
     "cache_creation": 8416,
     "cache_read": 63358,
     "fresh_input": 6,
     "output": 898,
     "turns": 3,
     "cost": 0.138319,
     "session_id": "b67a34a5-0de4-40fe-a950-48453f30ea5f",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration\nfor n in [5400, 45, 0, 3600, 3723, 60, 7260, 86399]:\n    print(n, format_duration(n))\nbad = [n for n in range(200000) if parse_duration(format_duration(n)) != n]\nprint('roundtrip failures:', bad[:5], len(bad))\ntry:\n    format_duration(-1)\nexcept ValueError as e:\n    print('raised:', e)\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration` added at `durations.py:22`. Round-trips cleanly through `parse_duration` for all values 0\u2013199999; negatives raise `ValueError`."
    },
    {
     "step": "roundtrip",
     "context": 75814,
     "cache_creation": 1383,
     "cache_read": 74426,
     "fresh_input": 5,
     "output": 1038,
     "turns": 3,
     "cost": 0.077018,
     "session_id": "b67a34a5-0de4-40fe-a950-48453f30ea5f",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','2h','0s','01h','1h0m','60s',' 45s ','abc','','1m30h']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok` added at `durations.py:41`. One judgment call worth flagging: strings `parse_duration` rejects (`'abc'`, `''`) would otherwise propagate a `ValueError` out of a predicate, so I catch it and return `False`."
    }
   ],
   "total_context": 260476,
   "total_cache_creation": 16989,
   "total_cache_read": 242888,
   "total_output": 3046,
   "total_turns": 11,
   "total_tool_calls": 8,
   "total_cost": 0.367807,
   "wall": 50.6,
   "durations_py_lines": 47,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113324,
     "cache_creation": 7278,
     "cache_read": 105458,
     "fresh_input": 588,
     "output": 1156,
     "turns": 5,
     "cost": 0.15467699999999998,
     "session_id": "efa3f8c2-b219-4fbe-bb8e-635560818fed",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_0"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h2m3s','0s','90m']:\n    print(repr(s), parse_duration(s))\nfor bad in ['','30m1h','abc','1d','5']:\n    try:\n        parse_duration(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise', repr(bad))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` is in `durations.py:10`. Accepts any combination of `<redacted-local-path>` in largest-first order, returns an int; raises `ValueError` on empty, out-of-order, unitless, or unknown-unit input. Verified against the cases above."
    },
    {
     "step": "format",
     "context": 138594,
     "cache_creation": 5237,
     "cache_read": 132754,
     "fresh_input": 603,
     "output": 1476,
     "turns": 6,
     "cost": 0.15593800000000002,
     "session_id": "94dcadce-4a77-445d-b245-b3e967ddc8fc",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la && find . -name \"durations.py\" null"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\nfor n in [0,1,45,60,90,3600,3660,5400,7325,86399,86400,123456]:\n    s=f(n); assert p(s)==n, (n,s); print(n,'->',s)\ntry: f(-1)\nexcept ValueError as e: print('neg ok:', e)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` added at `durations.py:29`. Verified every output round-trips through `parse_duration`. Negative input raises `ValueError` since `parse_duration` has no syntax for it."
    },
    {
     "step": "roundtrip",
     "context": 114724,
     "cache_creation": 4822,
     "cache_read": 109336,
     "fresh_input": 566,
     "output": 1140,
     "turns": 5,
     "cost": 0.131594,
     "session_id": "732a8871-2938-42c5-b529-45eb001e72d8",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_0"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s','2h','1h0m30s','90m',' 45s','','xyz','01h']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\nAdded `round_trip_ok(s)` above `format_duration` in `durations.py:28`. Canonical strings (`1h30m`, `45s`, `0s`) return True; non-canonical (`90m`, `1h0m30s`, `01h`) and unparseable input return False \u2014 invalid strings are caught rather than propagating `ValueError`, since a string `parse_duration` rejects can't round-trip."
    }
   ],
   "total_context": 366642,
   "total_cache_creation": 17337,
   "total_cache_read": 347548,
   "total_output": 3772,
   "total_turns": 16,
   "total_tool_calls": 13,
   "total_cost": 0.442209,
   "wall": 67.8,
   "durations_py_lines": 56,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 92556,
     "cache_creation": 7949,
     "cache_read": 83890,
     "fresh_input": 717,
     "output": 1718,
     "turns": 4,
     "cost": 0.164854,
     "session_id": "3f26f13c-e1ad-4560-a9e6-0eebdae4f427",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\nfor s in ['1h30m','45s','2h','1h','1h0m5s','90m','','x','1m1h','0s']:\n    try: p = parse_duration(s)\n    except ValueError as e: p = 'ERR'\n    print(repr(s), p, round_trip_ok(s))\nfor n in [0,45,5400,3600,3661,86399]:\n    print(n, format_duration(n), parse_duration(format_duration(n))==n)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "All three functions are in `durations.py` and verified: `parse_duration` (regex-based, enforces largest-first order and rejects malformed input with `ValueError`), `format_duration` (omits zero units, `0` \u2192 `'0s'`), and `round_trip_ok` (returns `False` for non-canonical inputs like `'90m'` and for unparseable strings).\n\nDONE"
    }
   ],
   "total_context": 92556,
   "total_cache_creation": 7949,
   "total_cache_read": 83890,
   "total_output": 1718,
   "total_turns": 4,
   "total_tool_calls": 3,
   "total_cost": 0.164854,
   "wall": 24.5,
   "durations_py_lines": 40,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90476,
     "cache_creation": 7155,
     "cache_read": 82735,
     "fresh_input": 586,
     "output": 1032,
     "turns": 4,
     "cost": 0.1389755,
     "session_id": "74cc0b4c-fe21-42b6-98a6-ea9941f0610e",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor s in ['1h30m','45s','2h','1h','2h3m4s','30m','0s']:\n    print(repr(s), p(s))\nfor bad in ['','30m1h','5','abc','1d','1h 30m']:\n    try:\n        print(repr(bad), p(bad), 'NO ERROR')\n    except ValueError as e:\n        print(repr(bad), 'ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration(s)` is in `durations.py:10`. It matches `<redacted-local-path>` parts in largest-first order, returns an int, and raises `ValueError` on unknown-unit input. Verified against the cases above."
    },
    {
     "step": "format",
     "context": 121544,
     "cache_creation": 9329,
     "cache_read": 112205,
     "fresh_input": 10,
     "output": 1366,
     "turns": 5,
     "cost": 0.1835925,
     "session_id": "74cc0b4c-fe21-42b6-98a6-ea9941f0610e",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p, format_duration as f\nfor n in [0, 45, 60, 3600, 5400, 7384, 3601, 90061]:\n    print(n, '->', repr(f(n)), 'roundtrip', p(f(n)) == n)\nprint('all roundtrip 0..20000:', all(p(f(n)) == n for n in range(20001)))\ntry:\n    f(-1)\nexcept ValueError as e:\n    print('negative ->', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration(seconds)` is in `durations.py:31`. It emits s largest-first, skips zero units, returns `'0s'` for zero, and raises `ValueError` on negatives (which `parse_duration` couldn't read back). Verified `parse_duration(format_duration(n)) == n` for every n from 0 to 20000, plus the cases shown above."
    },
    {
     "step": "roundtrip",
     "context": 78329,
     "cache_creation": 1209,
     "cache_read": 77115,
     "fresh_input": 5,
     "output": 797,
     "turns": 3,
     "cost": 0.07059750000000001,
     "session_id": "74cc0b4c-fe21-42b6-98a6-ea9941f0610e",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m','45s','2h','0s','2h3m4s','25h1m1s','0h45s','1h0m','00s',' 45s ','90m','abc','','30m1h']:\n    print(repr(s), '->', r(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok(s)` is in `durations.py:55`. Strings that `parse_duration` rejects return `False` rather than propagating the `ValueError` \u2014 that's the reading of \"False otherwise\" I took; say the word if you'd rather it raise. Non-canonical but parseable forms (`'0h45s'`, `'1h0m'`, `'00s'`, `' 45s '`, `'90m'`) correctly come back `False`."
    }
   ],
   "total_context": 290349,
   "total_cache_creation": 17693,
   "total_cache_read": 272055,
   "total_output": 3195,
   "total_turns": 12,
   "total_tool_calls": 9,
   "total_cost": 0.393165,
   "wall": 51.3,
   "durations_py_lines": 59,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113338,
     "cache_creation": 7299,
     "cache_read": 105451,
     "fresh_input": 588,
     "output": 1198,
     "turns": 5,
     "cost": 0.15595350000000002,
     "session_id": "dde0b3ab-1a0b-4679-a044-3ee24422b6cc",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_1"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h2m3s','90m','0s']:\n    print(repr(s), parse_duration(s))\nfor bad in ['','abc','30m1h','1h30','5x']:\n    try:\n        parse_duration(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('raised:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:10`. It regex-matches optional `<redacted-local-path>` groups in largest-first order and sums them; invalid or empty inputs raise `ValueError`. Verified against `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723, plus rejection of `30m1h`, `1h30`, `abc`, and `''`."
    },
    {
     "step": "format",
     "context": 138592,
     "cache_creation": 5224,
     "cache_read": 132765,
     "fresh_input": 603,
     "output": 1640,
     "turns": 6,
     "cost": 0.1599135,
     "session_id": "e30609ea-c6bd-4708-adf4-f04a5de0ed18",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_1"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\nfor n in [0,45,60,3600,5400,3601,86399,7200,59,120]:\n    s=f(n); assert p(s)==n, (n,s); print(n, s)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\nAdded `format_duration` to `durations.py:26`. Round-trips through `parse_duration` for the cases above; negative input raises `ValueError` since no accepted string represents it."
    },
    {
     "step": "roundtrip",
     "context": 92487,
     "cache_creation": 4829,
     "cache_read": 87094,
     "fresh_input": 564,
     "output": 1149,
     "turns": 4,
     "cost": 0.12075799999999999,
     "session_id": "1cecdffa-7846-4841-a20d-3c1464ceef22",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s','2h','01h','1h0m','60s',' 1h ','','bogus']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok(s)` added at `durations.py:47`. One judgment call: `parse_duration` raises `ValueError` on unparseable input, so I catch it and return `False` rather than let it propagate \u2014 that reads as the intent of \"False otherwise\". Non-canonical but parseable strings (`01h`, `1h0m`, `60s`, `' 1h '`) also correctly give `False`."
    }
   ],
   "total_context": 344417,
   "total_cache_creation": 17352,
   "total_cache_read": 325310,
   "total_output": 3987,
   "total_turns": 15,
   "total_tool_calls": 12,
   "total_cost": 0.436625,
   "wall": 61.6,
   "durations_py_lines": 56,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 92107,
     "cache_creation": 7673,
     "cache_read": 83717,
     "fresh_input": 717,
     "output": 1687,
     "turns": 4,
     "cost": 0.1612325,
     "session_id": "f7014ada-48d3-4b31-99b9-b2db3b12aad9",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\nprint(parse_duration('1h30m'), parse_duration('45s'), parse_duration('2h'), parse_duration('1h2m3s'))\nprint(format_duration(5400), format_duration(45), format_duration(0), format_duration(3661))\nprint(round_trip_ok('1h30m'), round_trip_ok('45s'), round_trip_ok('90m'), round_trip_ok('0s'), round_trip_ok('abc'), round_ <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "All three added to `durations.py` and verified: `parse_duration` (5400 for `'1h30m'`), `format_duration` (`'1h30m'`, `'45s'`, `'0s'`), and `round_trip_ok` (True for `'1h30m'`, False for `'90m'`).\n\nOne judgment call worth flagging: the spec didn't say what invalid input should do, so `parse_duration` raises `ValueError` on unparseable strings (including out-of-order units like `'30m1h'`), and `round_trip_ok` catches that and returns False.\n\nDONE"
    }
   ],
   "total_context": 92107,
   "total_cache_creation": 7673,
   "total_cache_read": 83717,
   "total_output": 1687,
   "total_turns": 4,
   "total_tool_calls": 3,
   "total_cost": 0.161233,
   "wall": 23.9,
   "durations_py_lines": 51,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113271,
     "cache_creation": 7262,
     "cache_read": 105421,
     "fresh_input": 588,
     "output": 1237,
     "turns": 5,
     "cost": 0.1565235,
     "session_id": "f9b26597-0789-4ed9-9569-df14fa2f71f8",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_session_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h','3m','1h2m3s','0s']:\n    print(s, parse_duration(s))\nfor bad in ['','30m1h','abc','5x','1.5h']:\n    try:\n        parse_duration(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise', repr(bad))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` is in `durations.py:10` \u2014 regex-based, returns an int, raises `ValueError` on out-of-order input. Verified against `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723, and rejects `30m1h`, `1.5h`, `5x`, `''`."
    },
    {
     "step": "format",
     "context": 97158,
     "cache_creation": 9007,
     "cache_read": 88143,
     "fresh_input": 8,
     "output": 1254,
     "turns": 4,
     "cost": 0.1655315,
     "session_id": "f9b26597-0789-4ed9-9569-df14fa2f71f8",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration\nfor n in [5400, 45, 0, 7200, 3723, 60, 3600, 86399]:\n    print(n, format_duration(n))\nbad = [n for n in range(0, 200000) if parse_duration(format_duration(n)) != n]\nprint('roundtrip mismatches:', bad[:5], len(bad))\ntry:\n    format_duration(-1); print('NO RAISE')\nexcept ValueError:\n    print('ok raise on negative')\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration` is in `durations.py:29`. Round-trips cleanly with `parse_duration` for every value 0\u2013199999 (0 mismatches); `5400`\u2192`1h30m`, `45`\u2192`45s`, `0`\u2192`0s`, `7200`\u2192`2h`. Negatives raise `ValueError`, since there's no string `parse_duration` would accept for them."
    },
    {
     "step": "roundtrip",
     "context": 77457,
     "cache_creation": 1236,
     "cache_read": 76216,
     "fresh_input": 5,
     "output": 860,
     "turns": 3,
     "cost": 0.071993,
     "session_id": "f9b26597-0789-4ed9-9569-df14fa2f71f8",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','2h','0s','1h2m3s','1h0m','0m','01h',' 1h','1h30m0s','abc','','30m1h']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok` is in `durations.py:47`. True for canonical strings (`1h30m`, `45s`, `0s`, `1h2m3s`), False for non-canonical spellings (`1h0m`, `01h`, `' 1h'`, `1h30m0s`) and for input `parse_duration` rejects \u2014 those raise `ValueError`, which I catch and return False, since a string that can't be parsed can't round-trip."
    }
   ],
   "total_context": 287886,
   "total_cache_creation": 17505,
   "total_cache_read": 269780,
   "total_output": 3351,
   "total_turns": 12,
   "total_tool_calls": 9,
   "total_cost": 0.394048,
   "wall": 51.6,
   "durations_py_lines": 52,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": false,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90272,
     "cache_creation": 6989,
     "cache_read": 82697,
     "fresh_input": 586,
     "output": 1010,
     "turns": 4,
     "cost": 0.1367665,
     "session_id": "dda40927-67fd-4d4b-9a89-798a8ef12d49",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('90m'))\nfor bad in ['', '30m1h', 'abc', '5x', '1h30']:\n    try:\n        p(bad); print('NO ERROR', repr(bad))\n    except ValueError as e:\n        print('ok:', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:10` \u2014 regex-based, accepts s in any combination largest-first, returns an int, raises `ValueError` on out-of-order input. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723."
    },
    {
     "step": "format",
     "context": 138942,
     "cache_creation": 5276,
     "cache_read": 133063,
     "fresh_input": 603,
     "output": 1599,
     "turns": 6,
     "cost": 0.15957749999999998,
     "session_id": "2468e5f1-ff40-458d-ab7b-2aedd0e8c599",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "find fresh_session_2 -name \"durations.py\""
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration, parse_duration\nfor n in [0, 45, 60, 3600, 5400, 3601, 7325, 86399]:\n    s = format_duration(n)\n    assert parse_duration(s) == n, (n, s)\n    print(n, '->', s)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` is in `durations.py:31`; round-trips through `parse_duration` for the cases above. One judgment call: negative input raises `ValueError`, since `parse_duration` can't read such a string back."
    },
    {
     "step": "roundtrip",
     "context": 68584,
     "cache_creation": 4429,
     "cache_read": 63593,
     "fresh_input": 562,
     "output": 663,
     "turns": 3,
     "cost": 0.0928475,
     "session_id": "3c54b7a1-fef7-4322-a726-5b7c488e2cd5",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 0,
     "reply": "DONE\n\nOne note: since `parse_duration` strips whitespace but the comparison is against the original `s`, inputs like `\" 45s\"` return False \u2014 they parse fine but don't round-trip literally, which matches the spec as written."
    }
   ],
   "total_context": 297798,
   "total_cache_creation": 16694,
   "total_cache_read": 279353,
   "total_output": 3272,
   "total_turns": 13,
   "total_tool_calls": 10,
   "total_cost": 0.389192,
   "wall": 55.8,
   "durations_py_lines": 59,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 115209,
     "cache_creation": 7929,
     "cache_read": 106561,
     "fresh_input": 719,
     "output": 1812,
     "turns": 5,
     "cost": 0.1783495,
     "session_id": "d3c4ac58-5554-4df4-870e-19cca6d08b51",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_prompt_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\ncases = ['1h30m','45s','2h','0s','1h','1h1m1s','3661s']\nfor c in cases:\n    print(c, parse_duration(c), format_duration(parse_duration(c)), round_trip_ok(c))\nprint(format_duration(5400), format_duration(45), format_duration(0), format_duration(3600))\nprint(round_trip_ok('90m'), round_trip_ok('30m1h'), round_trip_ok(' <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "All three functions are in `durations.py` and verified:\n\n- `parse_duration(s)` \u2014 regex-anchored on `(\\d+h)?(\\d+m)?(\\d+s)?`, so units are accepted only largest-first and at most once; raises `ValueError` on anything else (including the empty string).\n- `format_duration(seconds)` \u2014 omits zero units, returns `'0s'` for zero.\n- `round_trip_ok(s)` \u2014 returns `False` rather than propagating `ValueError` for unparseable input, since a non-duration string can't round trip.\n\nSpot checks: `'1h30m'`\u21925400\u2192`'1h30m'`, `'45s'`\u219245\u2192`'45s'`, `'3661s'` parses to 3661 but formats to `'1h1m1s'`, so `round_trip_ok('"
    }
   ],
   "total_context": 115209,
   "total_cache_creation": 7929,
   "total_cache_read": 106561,
   "total_output": 1812,
   "total_turns": 5,
   "total_tool_calls": 4,
   "total_cost": 0.178349,
   "wall": 26.6,
   "durations_py_lines": 40,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113271,
     "cache_creation": 7254,
     "cache_read": 105429,
     "fresh_input": 588,
     "output": 1182,
     "turns": 5,
     "cost": 0.1550725,
     "session_id": "a5924bee-9e54-47dc-bb3c-c7f76573112e",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h2m3s','90m']:\n    print(s, parse_duration(s))\nfor bad in ['','30m1h','abc','1d']:\n    try:\n        parse_duration(bad); print(bad,'NO ERROR')\n    except ValueError as e:\n        print(bad,'->',e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration(s)` is in `durations.py:10`. Single regex enforcing largest-first ordering, sums the matched groups; raises `ValueError` on out-of-order input. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723, and `<redacted-local-path>`''` all rejected."
    },
    {
     "step": "format",
     "context": 96759,
     "cache_creation": 8914,
     "cache_read": 87837,
     "fresh_input": 8,
     "output": 1158,
     "turns": 4,
     "cost": 0.16204849999999998,
     "session_id": "a5924bee-9e54-47dc-bb3c-c7f76573112e",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration\nfor n in [0,45,5400,3723,7200,60,3600,59,86399]:\n    s = format_duration(n)\n    assert parse_duration(s) == n, (n, s)\n    print(n, '->', s)\n# exhaustive round-trip\nfor n in range(0, 200000):\n    assert parse_duration(format_duration(n)) == n, n\nprint('round-trip 0..199999 OK')\ntry:\n    format_duration(-1); print('NO ERROR')\nexcept  <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration(seconds)` is in `durations.py:22`. Greedy divmod over s, skipping zero units, with `0s` as the empty case. Round-trips exactly through `parse_duration` for every value 0\u2013199999 (verified exhaustively); negative input raises `ValueError` since it has no representable form."
    },
    {
     "step": "roundtrip",
     "context": 76939,
     "cache_creation": 1143,
     "cache_read": 75791,
     "fresh_input": 5,
     "output": 753,
     "turns": 3,
     "cost": 0.0681755,
     "session_id": "a5924bee-9e54-47dc-bb3c-c7f76573112e",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','2h','0s','1h2m3s','90m','0h45s',' 45s ','60s','1h0m','30m1h','abc','','1d']:\n    print(repr(s), '->', round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok(s)` is in `durations.py:41`. It returns True only for canonical strings; non-canonical-but-parseable forms (`90m`, `0h45s`, `1h0m`, whitespace-padded) return False, and inputs `parse_duration` rejects are caught and return False rather than propagating `ValueError` \u2014 that seemed the intended reading of \"False otherwise,\" so flagging it in case you'd rather the exception escape."
    }
   ],
   "total_context": 286969,
   "total_cache_creation": 17311,
   "total_cache_read": 269057,
   "total_output": 3093,
   "total_turns": 12,
   "total_tool_calls": 9,
   "total_cost": 0.385296,
   "wall": 55.3,
   "durations_py_lines": 53,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90382,
     "cache_creation": 7040,
     "cache_read": 82756,
     "fresh_input": 586,
     "output": 1030,
     "turns": 4,
     "cost": 0.13778600000000002,
     "session_id": "67a8643a-65b1-455a-b361-702c2bdf57f5",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('90m'))\nfor bad in ['', 'abc', '30m1h', '5x']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise:', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration` is in `durations.py:10`; verified against `<redacted-local-path>` and rejecting empty, non-numeric, out-of-order (`30m1h`), and unknown-unit input with `ValueError`."
    },
    {
     "step": "format",
     "context": 138419,
     "cache_creation": 5197,
     "cache_read": 132619,
     "fresh_input": 603,
     "output": 1572,
     "turns": 6,
     "cost": 0.1578705,
     "session_id": "b0ceb8e7-d0cc-4677-bd32-5047510cac61",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration, parse_duration\nfor n in [0, 45, 60, 3600, 5400, 3601, 3660, 86399, 7325]:\n    s = format_duration(n)\n    assert parse_duration(s) == n, (n, s)\n    print(n, '->', s)\ntry:\n    format_duration(-1)\nexcept ValueError as e:\n    print('neg ok:', e)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` is in `durations.py:26`, round-tripping through `parse_duration` for every case I tested. One judgment call: negatives raise `ValueError`, since there's no representable form for them."
    },
    {
     "step": "roundtrip",
     "context": 115598,
     "cache_creation": 5154,
     "cache_read": 109878,
     "fresh_input": 566,
     "output": 1297,
     "turns": 5,
     "cost": 0.13913,
     "session_id": "d4dfa709-a4b5-488f-8102-d2e2fe04be96",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','2h','0s','90m',' 1h','0h5m','','xyz','1h0m30s']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`round_trip_ok` is in `durations.py:47`. It returns `False` (rather than propagating) for strings `parse_duration` rejects, since a raised `ValueError` isn't an equality match."
    }
   ],
   "total_context": 344399,
   "total_cache_creation": 17391,
   "total_cache_read": 325253,
   "total_output": 3899,
   "total_turns": 15,
   "total_tool_calls": 12,
   "total_cost": 0.434786,
   "wall": 61.4,
   "durations_py_lines": 55,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 4,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 115080,
     "cache_creation": 7869,
     "cache_read": 106492,
     "fresh_input": 719,
     "output": 1550,
     "turns": 5,
     "cost": 0.17116499999999998,
     "session_id": "850aeb6e-8d53-4f43-a9f9-d5f1a07cbf45",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_prompt_4"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\nfor s in ['1h30m','45s','2h','1h','1h0m30s','0s','90m','','5x','1m2h']:\n    try: p = parse_duration(s)\n    except ValueError as e: p = 'ValueError'\n    print(repr(s), p, round_trip_ok(s))\nfor n in [5400, 45, 0, 3600, 3661, 60]:\n    print(n, format_duration(n))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "All three functions are in `durations.py` and verified: `parse_duration` (rejects unknown units), `format_duration` (5400 \u2192 `1h30m`, 45 \u2192 `45s`, 0 \u2192 `0s`), and `round_trip_ok` (False on non-canonical forms like `90m` and on unparseable input rather than raising).\n\nDONE"
    }
   ],
   "total_context": 115080,
   "total_cache_creation": 7869,
   "total_cache_read": 106492,
   "total_output": 1550,
   "total_turns": 5,
   "total_tool_calls": 4,
   "total_cost": 0.171165,
   "wall": 23.4,
   "durations_py_lines": 41,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 4,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90206,
     "cache_creation": 6968,
     "cache_read": 82652,
     "fresh_input": 586,
     "output": 870,
     "turns": 4,
     "cost": 0.13301400000000002,
     "session_id": "44b7b268-991b-4d9b-8d27-4ac67ee7dd64",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h2m3s','90m']:\n    print(s, parse_duration(s))\nfor s in ['', 'abc', '30m1h', '1x']:\n    try:\n        parse_duration(s)\n        print(s, 'NO ERROR')\n    except ValueError as e:\n        print('ok raised:', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE"
    },
    {
     "step": "format",
     "context": 70805,
     "cache_creation": 8068,
     "cache_read": 62731,
     "fresh_input": 6,
     "output": 764,
     "turns": 3,
     "cost": 0.1311755,
     "session_id": "44b7b268-991b-4d9b-8d27-4ac67ee7dd64",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration\nfor n in [0, 45, 60, 5400, 3600, 3723, 7200, 86399]:\n    s = format_duration(n)\n    assert parse_duration(s) == n, (n, s)\n    print(n, '->', s)\ntry:\n    format_duration(-1)\n    print('NO ERROR')\nexcept ValueError as e:\n    print('ok raised:', e)\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE"
    },
    {
     "step": "roundtrip",
     "context": 74124,
     "cache_creation": 1163,
     "cache_read": 72956,
     "fresh_input": 5,
     "output": 820,
     "turns": 3,
     "cost": 0.068633,
     "session_id": "44b7b268-991b-4d9b-8d27-4ac67ee7dd64",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','2h','0s','1h2m3s','90m','0h30m',' 45s','abc','','30m1h','1h0m']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\nNon-canonical but parseable inputs like `'90m'` and `' 45s'` return `False`, since `format_duration` normalizes them."
    }
   ],
   "total_context": 235135,
   "total_cache_creation": 16199,
   "total_cache_read": 218339,
   "total_output": 2454,
   "total_turns": 10,
   "total_tool_calls": 7,
   "total_cost": 0.332823,
   "wall": 45.4,
   "durations_py_lines": 52,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 4,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113316,
     "cache_creation": 7276,
     "cache_read": 105452,
     "fresh_input": 588,
     "output": 1136,
     "turns": 5,
     "cost": 0.154154,
     "session_id": "f69f0bb7-0fb1-43dd-9755-da8ee09fc555",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_4"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h2m3s','90m']:\n    print(s, parse_duration(s))\nfor bad in ['','abc','30m1h','1h30']:\n    try:\n        parse_duration(bad); print(bad,'NO ERROR')\n    except ValueError as e:\n        print(repr(bad),'->',e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:10` \u2014 regex-based, accepts any s combination in largest-first order, raises `ValueError` on out-of-order input. Verified against the examples plus a few edge cases."
    },
    {
     "step": "format",
     "context": 138228,
     "cache_creation": 5084,
     "cache_read": 132541,
     "fresh_input": 603,
     "output": 1440,
     "turns": 6,
     "cost": 0.1534015,
     "session_id": "209af501-89f2-464e-ba16-391ee85cfb14",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_4"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration, parse_duration\nfor n in [0,45,60,3600,5400,3601,86399,7200,90061]:\n    s=format_duration(n)\n    assert parse_duration(s)==n, (n,s)\n    print(n,s)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE"
    },
    {
     "step": "roundtrip",
     "context": 115004,
     "cache_creation": 4960,
     "cache_read": 109478,
     "fresh_input": 566,
     "output": 1234,
     "turns": 5,
     "cost": 0.135395,
     "session_id": "8df2c024-0f5d-432f-9f2e-00dc9c164e59",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_4"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s','2h','01h','1h0m','', 'xyz',' 45s','90m']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\nOne judgment call: strings `parse_duration` rejects (`''`, `'xyz'`) return `False` rather than propagating `ValueError`. Note that `' 45s'` is also `False` \u2014 `parse_duration` strips whitespace, so the formatted result won't match the padded input."
    }
   ],
   "total_context": 366548,
   "total_cache_creation": 17320,
   "total_cache_read": 347471,
   "total_output": 3810,
   "total_turns": 16,
   "total_tool_calls": 13,
   "total_cost": 0.44295,
   "wall": 65.0,
   "durations_py_lines": 56,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 5,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 92432,
     "cache_creation": 7904,
     "cache_read": 83811,
     "fresh_input": 717,
     "output": 1769,
     "turns": 4,
     "cost": 0.1656395,
     "session_id": "b4e21752-0d0f-4c85-b30f-507d78d6a6d2",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\ncases = ['1h30m','45s','2h','1h','1h1m1s','0s','90m','3600s']\nfor c in cases:\n    print(repr(c), parse_duration(c), repr(format_duration(parse_duration(c))), round_trip_ok(c))\nprint(repr(format_duration(5400)), repr(format_duration(45)), repr(format_duration(0)), repr(format_duration(3661)))\nprint(round_trip_ok('bogu <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "All three added to `durations.py` and verified: `parse_duration` (regex over optional `<redacted-local-path>` groups, largest first), `format_duration` (5400 \u2192 `'1h30m'`, 45 \u2192 `'45s'`, 0 \u2192 `'0s'`), and `round_trip_ok`.\n\nTwo judgment calls worth flagging: invalid input to `parse_duration` raises `ValueError`, and `round_trip_ok` catches that to return `False` (an unparseable string can't round-trip). Non-canonical but valid inputs like `'90m'` correctly return `False`.\n\nDONE"
    }
   ],
   "total_context": 92432,
   "total_cache_creation": 7904,
   "total_cache_read": 83811,
   "total_output": 1769,
   "total_turns": 4,
   "total_tool_calls": 3,
   "total_cost": 0.165639,
   "wall": 24.0,
   "durations_py_lines": 50,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 5,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113299,
     "cache_creation": 7280,
     "cache_read": 105431,
     "fresh_input": 588,
     "output": 1179,
     "turns": 5,
     "cost": 0.1552585,
     "session_id": "cf8ec805-7b11-4001-8a7d-f1994c6be6e7",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_session_5"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h2m3s','90m']:\n    print(s, parse_duration(s))\nfor s in ['','30m1h','abc','5x']:\n    try:\n        parse_duration(s); print(s, 'NO ERROR')\n    except ValueError as e:\n        print(repr(s), 'ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` is in `durations.py:10` \u2014 regex-based, accepts any s combination in largest-first order, raises `ValueError` on empty or malformed input. Verified against `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723, and rejection of `<redacted-local-path>`''`."
    },
    {
     "step": "format",
     "context": 122347,
     "cache_creation": 9498,
     "cache_read": 112840,
     "fresh_input": 9,
     "output": 1298,
     "turns": 5,
     "cost": 0.183895,
     "session_id": "cf8ec805-7b11-4001-8a7d-f1994c6be6e7",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration\nfor n in [0, 45, 60, 3600, 5400, 3723, 7200, 86399]:\n    print(n, format_duration(n))\n# round-trip every value up to 2 days\nfor n in range(0, 172800):\n    s = format_duration(n)\n    assert parse_duration(s) == n, (n, s)\nprint('round-trip OK for 0..172799')\ntry:\n    format_duration(-1)\nexcept ValueError as e:\n    print('ValueError:' <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration` is in `durations.py:31`. It shares the unit table with `parse_duration` via `_UNITS`, omits zero-valued units, returns `'0s'` for zero, and raises `ValueError` on negatives (which `parse_duration` couldn't accept anyway). Verified `<redacted-local-path>` round-trip exactly for every value from 0 to 172799."
    },
    {
     "step": "roundtrip",
     "context": 78758,
     "cache_creation": 1265,
     "cache_read": 77487,
     "fresh_input": 6,
     "output": 1050,
     "turns": 3,
     "cost": 0.0776735,
     "session_id": "cf8ec805-7b11-4001-8a7d-f1994c6be6e7",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok, format_duration\nfor s in ['1h30m','45s','2h','0s','1h2m3s','23h59m59s']:\n    print(repr(s), round_trip_ok(s))\nfor s in ['90m','0h45s','1h0m','01h','  45s  ','','abc','30m1h']:\n    print(repr(s), round_trip_ok(s))\nassert all(round_trip_ok(format_duration(n)) for n in range(0, 172800))\nprint('all canonical forms round-trip OK')\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok` is in `durations.py:53`. One judgment call worth flagging: strings `parse_duration` rejects (`''`, `'abc'`, `'30m1h'`) return `False` rather than propagating the `ValueError` \u2014 a predicate that raises would be awkward, and an unparseable string plainly doesn't round-trip. Say the word if you'd rather it raise.\n\nNon-canonical but parseable inputs like `'90m'`, `'0h45s'`, and `'01h'` correctly return `False`. Verified that every canonical output of `format_duration` from 0 to 172799 returns `True`."
    }
   ],
   "total_context": 314404,
   "total_cache_creation": 18043,
   "total_cache_read": 295758,
   "total_output": 3527,
   "total_turns": 13,
   "total_tool_calls": 10,
   "total_cost": 0.416827,
   "wall": 57.4,
   "durations_py_lines": 58,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 5,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 112926,
     "cache_creation": 7183,
     "cache_read": 105155,
     "fresh_input": 588,
     "output": 1072,
     "turns": 5,
     "cost": 0.1514755,
     "session_id": "c6431742-5eb1-48ae-bf47-6bbe08151dde",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_5"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h30m15s','90m']:\n    print(s, parse_duration(s))\nfor bad in ['','30m1h','abc','5x']:\n    try:\n        parse_duration(bad); print('NO ERROR', repr(bad))\n    except ValueError as e:\n        print('ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE"
    },
    {
     "step": "format",
     "context": 114158,
     "cache_creation": 4620,
     "cache_read": 108937,
     "fresh_input": 601,
     "output": 1081,
     "turns": 5,
     "cost": 0.1279745,
     "session_id": "c9205ab3-3a44-425b-b9c8-26d48f8fcf45",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_5"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration, parse_duration\nfor n in [0, 45, 60, 5400, 3600, 3661, 7200, 119, 86399]:\n    s = format_duration(n)\n    print(n, s, parse_duration(s) == n)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE"
    },
    {
     "step": "roundtrip",
     "context": 92672,
     "cache_creation": 4968,
     "cache_read": 87140,
     "fresh_input": 564,
     "output": 1337,
     "turns": 4,
     "cost": 0.12687099999999998,
     "session_id": "a440ba45-7568-4e12-80e0-6486073abb32",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s','2h','0h','1h0m30s',' 45s ','bogus','']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE.\n\nAdded `round_trip_ok(s)` at the end of `durations.py:42`. One judgment call: `parse_duration` raises `ValueError` on invalid input, so I catch it and return `False` \u2014 an unparseable string can't round-trip."
    }
   ],
   "total_context": 319756,
   "total_cache_creation": 16771,
   "total_cache_read": 301232,
   "total_output": 3490,
   "total_turns": 14,
   "total_tool_calls": 11,
   "total_cost": 0.406321,
   "wall": 61.5,
   "durations_py_lines": 51,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch1",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 115096,
     "cache_creation": 7807,
     "cache_read": 106570,
     "fresh_input": 719,
     "output": 1589,
     "turns": 5,
     "cost": 0.171559,
     "session_id": "412af9bc-e87f-4307-b4c4-578f2c791ab9",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_prompt_0"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p, format_duration as f, round_trip_ok as r\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'))\nprint(f(5400), f(45), f(0), f(3600), f(3723))\nprint(r('1h30m'), r('90m'), r('0s'), r('2h0m'), r('bogus'), r(''))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\nAll three are in `durations.py` and verified: `parse_duration` handles s in any combination (largest first), `format_duration` drops zero units and returns `'0s'` for zero, and `round_trip_ok` returns `False` for non-canonical (`'90m'`, `'2h0m'`) or unparseable input rather than raising."
    }
   ],
   "total_context": 115096,
   "total_cache_creation": 7807,
   "total_cache_read": 106570,
   "total_output": 1589,
   "total_turns": 5,
   "total_tool_calls": 4,
   "total_cost": 0.171559,
   "wall": 27.9,
   "durations_py_lines": 47,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90584,
     "cache_creation": 7174,
     "cache_read": 82824,
     "fresh_input": 586,
     "output": 1078,
     "turns": 4,
     "cost": 0.14036,
     "session_id": "28f2072e-f879-4f14-9376-8638f64e5ef9",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor s in ['1h30m','45s','2h','1h','5m','1h2m3s','0s']:\n    print(repr(s), p(s))\nfor bad in ['', 'abc', '30m1h', '10']:\n    try: print(repr(bad), p(bad))\n    except ValueError as e: print(repr(bad), 'ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration` is in `durations.py:8`; verified against the examples plus invalid cases (out-of-order like `30m1h`, unitless, and empty raise `ValueError`)."
    },
    {
     "step": "format",
     "context": 96424,
     "cache_creation": 8895,
     "cache_read": 87521,
     "fresh_input": 8,
     "output": 1043,
     "turns": 4,
     "cost": 0.15882549999999998,
     "session_id": "28f2072e-f879-4f14-9376-8638f64e5ef9",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p, format_duration as f\nfor n in [0, 45, 60, 3600, 5400, 3723, 3601, 7200, 86399]:\n    s = f(n); assert p(s) == n, (n, s); print(n, '->', s)\n# round-trip sweep\nfor n in range(0, 100000):\n    assert p(f(n)) == n, n\nprint('round-trip 0..99999 ok')\ntry: f(-1)\nexcept ValueError as e: print('-1 ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration` is at `durations.py:21`. Round-trips through `parse_duration` for every value 0\u201399999; negatives raise `ValueError` since no accepted string represents them."
    },
    {
     "step": "roundtrip",
     "context": 77042,
     "cache_creation": 1309,
     "cache_read": 75728,
     "fresh_input": 5,
     "output": 950,
     "turns": 3,
     "cost": 0.07472899999999999,
     "session_id": "28f2072e-f879-4f14-9376-8638f64e5ef9",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\ncases = ['1h30m','45s','2h','0s','1h2m3s','23h59m59s',\n         '0h45s','01h','1h0m','60s','90m',' 45s ','','abc','30m1h','10']\nfor c in cases: print(repr(c), r(c))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok` is at `durations.py:44`. Canonical forms return True; non-canonical-but-parseable inputs (`0h45s`, `01h`, `60s`, `90m`, padded whitespace) and unparseable ones both return False \u2014 I catch `ValueError` rather than letting it propagate, since a rejected string doesn't round-trip either."
    }
   ],
   "total_context": 264050,
   "total_cache_creation": 17378,
   "total_cache_read": 246073,
   "total_output": 3071,
   "total_turns": 11,
   "total_tool_calls": 8,
   "total_cost": 0.373914,
   "wall": 49.0,
   "durations_py_lines": 50,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113336,
     "cache_creation": 7276,
     "cache_read": 105472,
     "fresh_input": 588,
     "output": 1140,
     "turns": 5,
     "cost": 0.15426399999999998,
     "session_id": "8dda3323-591d-42c5-ace8-e6e198606073",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_0"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h2m3s','90m','0s']:\n    print(s, parse_duration(s))\nfor bad in ['','30m1h','abc','5x','1h 30m']:\n    try:\n        parse_duration(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise', repr(bad))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:10`. Regex-based, requires largest-first ordering, raises `ValueError` on unknown-unit input. Verified against the cases above."
    },
    {
     "step": "format",
     "context": 115012,
     "cache_creation": 5001,
     "cache_read": 109410,
     "fresh_input": 601,
     "output": 1391,
     "turns": 5,
     "cost": 0.139771,
     "session_id": "722fde7b-bf50-4e41-8ce9-31de63297aba",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "find fresh_session_0 -name \"*.py\" | head -50"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration, parse_duration\ncases = [0, 1, 45, 60, 90, 3600, 5400, 3601, 7200, 86399, 123456]\nfor c in cases:\n    s = format_duration(c)\n    assert parse_duration(s) == c, (c, s)\n    print(c, '->', s)\ntry:\n    format_duration(-1)\nexcept ValueError as e:\n    print('negative ->', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` added at `durations.py:28`; round-trips through `parse_duration` for all cases tested, and raises `ValueError` on negative input (unrepresentable in the format)."
    },
    {
     "step": "roundtrip",
     "context": 114488,
     "cache_creation": 4705,
     "cache_read": 109217,
     "fresh_input": 566,
     "output": 1046,
     "turns": 5,
     "cost": 0.1280545,
     "session_id": "128b97a6-9a43-40b8-b11c-6f22bc5cea50",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_0"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s',' 45s','1h0m','90m','bogus','']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`round_trip_ok(s)` is in `durations.py:47`. One judgment call worth flagging: inputs `parse_duration` rejects (e.g. `\"bogus\"`, `\"\"`) return `False` instead of propagating the `ValueError` \u2014 they're not round-trippable either way. Say the word if you'd rather it raise."
    }
   ],
   "total_context": 342836,
   "total_cache_creation": 16982,
   "total_cache_read": 324099,
   "total_output": 3577,
   "total_turns": 15,
   "total_tool_calls": 12,
   "total_cost": 0.42209,
   "wall": 73.8,
   "durations_py_lines": 56,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 115294,
     "cache_creation": 7981,
     "cache_read": 106594,
     "fresh_input": 719,
     "output": 1706,
     "turns": 5,
     "cost": 0.176236,
     "session_id": "b2fd0fcb-edaf-48b2-8a09-fb0f8a03407b",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_prompt_1"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\nfor s in ['1h30m','45s','2h','0s','1h','1h0m30s','90m','','5x','30m1h']:\n    try: p = parse_duration(s)\n    except ValueError as e: p = 'ValueError'\n    print(repr(s), p, format_duration(p) if isinstance(p,int) else '-', round_trip_ok(s))\nprint(format_duration(5400), format_duration(45), format_duration(3661), format <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "All three functions are in `durations.py` and verified:\n\n- `parse_duration` \u2014 regex-anchored so units must appear largest-first; rejects malformed input with `ValueError`.\n- `format_duration` \u2014 omits zero units, `0` \u2192 `'0s'`, rejects negatives.\n- `round_trip_ok` \u2014 returns `False` (rather than raising) for unparseable input, and correctly reports `False` for non-canonical forms like `'90m'` and `'1h0m30s'`.\n\nDONE"
    }
   ],
   "total_context": 115294,
   "total_cache_creation": 7981,
   "total_cache_read": 106594,
   "total_output": 1706,
   "total_turns": 5,
   "total_tool_calls": 4,
   "total_cost": 0.176236,
   "wall": 24.8,
   "durations_py_lines": 48,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90303,
     "cache_creation": 6997,
     "cache_read": 82720,
     "fresh_input": 586,
     "output": 1011,
     "turns": 4,
     "cost": 0.13686299999999998,
     "session_id": "feee8c40-d244-4ae3-90b1-9d283315cb0d",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('90m'))\nfor bad in ['', 'abc', '30m1h', '5x', '1.5h']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError:\n        print('ok raises', repr(bad))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:8`. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723, `90m`\u21925400; out-of-order (`30m1h`), empty, and malformed inputs raise `ValueError`."
    },
    {
     "step": "format",
     "context": 95953,
     "cache_creation": 8749,
     "cache_read": 87196,
     "fresh_input": 8,
     "output": 1128,
     "turns": 4,
     "cost": 0.159328,
     "session_id": "feee8c40-d244-4ae3-90b1-9d283315cb0d",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\nfor n in [0, 45, 60, 5400, 3600, 3723, 7200, 3601, 86399]:\n    s = f(n); assert p(s) == n, (n, s); print(n, '->', s)\nassert all(p(f(n)) == n for n in range(0, 100000, 7))\nprint('roundtrip ok')\ntry:\n    f(-1); print('NO RAISE')\nexcept ValueError: print('ok raises on negative')\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration` added at `durations.py:22`. Verified round-trip `parse_duration(format_duration(n)) == n` for every 7th value up to 100000, plus the examples (5400\u2192`1h30m`, 45\u2192`45s`, 0\u2192`0s`). Negative input raises `ValueError`, since `parse_duration` can't accept it."
    },
    {
     "step": "roundtrip",
     "context": 76775,
     "cache_creation": 1389,
     "cache_read": 75381,
     "fresh_input": 5,
     "output": 998,
     "turns": 3,
     "cost": 0.0765555,
     "session_id": "feee8c40-d244-4ae3-90b1-9d283315cb0d",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m', '45s', '0s', '2h', '1h2m3s', '23h59m59s']:\n    print(repr(s), r(s)); assert r(s)\nfor s in ['90m', '0h30m', '1h0m', '01h', ' 45s', '', 'abc', '30m1h', '0m']:\n    print(repr(s), r(s)); assert not r(s)\nprint('ok')\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok` added at `durations.py:40`. Canonical forms (`1h30m`, `45s`, `0s`) return True; non-canonical but parseable ones (`90m`, `0h30m`, `01h`, `' 45s'`) return False, as do inputs `parse_duration` rejects \u2014 I chose to catch that `ValueError` and return False rather than let it propagate, since the function is a predicate."
    }
   ],
   "total_context": 263031,
   "total_cache_creation": 17135,
   "total_cache_read": 245297,
   "total_output": 3137,
   "total_turns": 11,
   "total_tool_calls": 8,
   "total_cost": 0.372746,
   "wall": 49.9,
   "durations_py_lines": 47,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90421,
     "cache_creation": 7066,
     "cache_read": 82769,
     "fresh_input": 586,
     "output": 1037,
     "turns": 4,
     "cost": 0.1382275,
     "session_id": "f772bed7-b944-4be3-94ec-61a3534f9ffe",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('90m'))\nfor bad in ['', 'abc', '30m1h', '1x', '5']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise:', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:11`. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723; out-of-order (`30m1h`), unitless, and malformed inputs raise `ValueError`."
    },
    {
     "step": "format",
     "context": 138400,
     "cache_creation": 5208,
     "cache_read": 132589,
     "fresh_input": 603,
     "output": 1574,
     "turns": 6,
     "cost": 0.1580155,
     "session_id": "32188e7c-6099-45a2-adb5-920daa822996",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_1"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration, parse_duration\nfor n in [0, 1, 45, 60, 3600, 5400, 3601, 3660, 86399, 90061]:\n    s = format_duration(n)\n    assert parse_duration(s) == n, (n, s)\n    print(n, '->', s)\ntry:\n    format_duration(-1)\nexcept ValueError as e:\n    print('neg ->', e)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` added to `durations.py:29`; round-trips through `parse_duration` for the cases above. One judgment call: negative input raises `ValueError` since `parse_duration` has no representation for it."
    },
    {
     "step": "roundtrip",
     "context": 115369,
     "cache_creation": 5120,
     "cache_read": 109683,
     "fresh_input": 566,
     "output": 1321,
     "turns": 5,
     "cost": 0.1392725,
     "session_id": "3f9994d4-cc63-46b2-92d0-d317d750d3e9",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_1"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s','2h','90m',' 45s ','','xyz','1h0m30s']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\nNote: invalid inputs (which make `parse_duration` raise) return `False` rather than propagating the `ValueError`."
    }
   ],
   "total_context": 344190,
   "total_cache_creation": 17394,
   "total_cache_read": 325041,
   "total_output": 3932,
   "total_turns": 15,
   "total_tool_calls": 12,
   "total_cost": 0.435516,
   "wall": 61.5,
   "durations_py_lines": 56,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 115501,
     "cache_creation": 8064,
     "cache_read": 106718,
     "fresh_input": 719,
     "output": 1838,
     "turns": 5,
     "cost": 0.18042800000000003,
     "session_id": "efe76640-0710-4dd2-ab75-0e938e3aa200",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_prompt_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "cd && python3 -c \"\nfrom durations import parse_duration as p, format_duration as f, round_trip_ok as r\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('0s'))\nprint(f(5400), f(45), f(7200), f(3723), f(0), f(60))\nprint(r('1h30m'), r('45s'), r <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "All three functions are in `durations.py` and verified:\n\n- `parse_duration(s)` \u2014 regex-matched `<redacted-local-path>` in that order, each optional, returns int seconds; raises `ValueError` on garbage.\n- `format_duration(seconds)` \u2014 drops zero-valued units, `0` gives `'0s'`.\n- `round_trip_ok(s)` \u2014 returns `False` rather than raising when `s` isn't parseable (e.g. `'bogus'`, `''`); `'90m'` and `'1h0m30s'` correctly return `False` since they aren't the shortest form.\n\nDONE"
    }
   ],
   "total_context": 115501,
   "total_cache_creation": 8064,
   "total_cache_read": 106718,
   "total_output": 1838,
   "total_turns": 5,
   "total_tool_calls": 4,
   "total_cost": 0.180428,
   "wall": 25.9,
   "durations_py_lines": 43,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 112852,
     "cache_creation": 7146,
     "cache_read": 105118,
     "fresh_input": 588,
     "output": 1042,
     "turns": 5,
     "cost": 0.150337,
     "session_id": "415672d9-6758-434e-8e71-bc816b37fe30",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls one_session_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor x in ['1h30m','45s','2h','1h2m3s','90m']:\n    print(x, p(x))\nfor bad in ['', 'abc', '30m1h', '5']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE"
    },
    {
     "step": "format",
     "context": 95854,
     "cache_creation": 8656,
     "cache_read": 87190,
     "fresh_input": 8,
     "output": 1131,
     "turns": 4,
     "cost": 0.15847,
     "session_id": "415672d9-6758-434e-8e71-bc816b37fe30",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p, format_duration as f\nfor n in [0, 45, 60, 3600, 5400, 3723, 7200, 3601, 86399]:\n    s = f(n)\n    print(n, s, p(s) == n)\ntry:\n    f(-1); print('NO RAISE')\nexcept ValueError as e:\n    print('ok raise', e)\nprint('roundtrip all:', all(p(f(n)) == n for n in range(1, 100000)))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\nOne note: `1h1s` (3601) is valid \u2014 `parse_duration` accepts a skipped middle unit, so the round trip holds for all values 0\u201399999 as tested. Negative input raises `ValueError`, since it has no representation."
    },
    {
     "step": "roundtrip",
     "context": 76116,
     "cache_creation": 1110,
     "cache_read": 75001,
     "fresh_input": 5,
     "output": 767,
     "turns": 3,
     "cost": 0.06780050000000001,
     "session_id": "415672d9-6758-434e-8e71-bc816b37fe30",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m','45s','2h','0s','1h1s','90m','01h','1h0m','0h30m',' 45s ','','abc','30m1h']:\n    print(repr(s), r(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\nInvalid strings (`''`, `'abc'`, `'30m1h'`) return `False` rather than propagating `parse_duration`'s `ValueError` \u2014 that's the reading of \"False otherwise\" I went with. Non-canonical but parseable forms like `'90m'`, `'1h0m'`, and `' 45s '` also return `False`, since they differ from what `format_duration` emits."
    }
   ],
   "total_context": 284822,
   "total_cache_creation": 16912,
   "total_cache_read": 267309,
   "total_output": 2940,
   "total_turns": 12,
   "total_tool_calls": 9,
   "total_cost": 0.376607,
   "wall": 48.2,
   "durations_py_lines": 55,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113447,
     "cache_creation": 7387,
     "cache_read": 105472,
     "fresh_input": 588,
     "output": 1227,
     "turns": 5,
     "cost": 0.15754899999999997,
     "session_id": "2b1f5824-64e1-42fc-82c5-9da834d10532",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor s in ['1h30m','45s','2h','1h','30m','1h2m3s','2h30s','0s']:\n    print(repr(s), p(s))\nfor bad in ['','abc','30m1h','5','1h30','1.5h']:\n    try:\n        print(repr(bad), p(bad))\n    except ValueError as e:\n        print(repr(bad), 'ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:10` \u2014 regex-based, accepts any combination of s in largest-first order, raises `ValueError` otherwise. Verified against the examples plus edge cases (`1h2m3s` \u2192 3723, `0s` \u2192 0, out-of-order `30m1h` rejected)."
    },
    {
     "step": "format",
     "context": 138464,
     "cache_creation": 5202,
     "cache_read": 132659,
     "fresh_input": 603,
     "output": 1599,
     "turns": 6,
     "cost": 0.15861550000000002,
     "session_id": "dce5faf5-6a30-4b78-ba0b-638aa50426da",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration, parse_duration\ncases=[0,45,60,3600,5400,3661,86399,7200]\nfor c in cases:\n    s=format_duration(c)\n    assert parse_duration(s)==c, (c,s)\n    print(c,'->',s)\ntry:\n    format_duration(-1)\nexcept ValueError as e:\n    print('neg ok:',e)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` added to `durations.py:29`. Round-trips through `parse_duration` on all tested values; negative input raises `ValueError` (unspecified in your request, since `parse_duration` can't produce negatives)."
    },
    {
     "step": "roundtrip",
     "context": 92540,
     "cache_creation": 4861,
     "cache_read": 87115,
     "fresh_input": 564,
     "output": 1168,
     "turns": 4,
     "cost": 0.12156349999999999,
     "session_id": "3db587be-fef9-4609-acfd-f528b516aae3",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s','2h','0h45s','01s',' 45s','','bogus','90m']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok(s)` is in `durations.py:46`. One judgment call: invalid strings (`''`, `'bogus'`) would raise `ValueError` out of `parse_duration`, so I catch it and return `False` per \"False otherwise\" \u2014 say the word if you'd rather it propagate."
    }
   ],
   "total_context": 344451,
   "total_cache_creation": 17450,
   "total_cache_read": 325246,
   "total_output": 3994,
   "total_turns": 15,
   "total_tool_calls": 12,
   "total_cost": 0.437728,
   "wall": 60.4,
   "durations_py_lines": 55,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 92553,
     "cache_creation": 7925,
     "cache_read": 83911,
     "fresh_input": 717,
     "output": 1866,
     "turns": 4,
     "cost": 0.1683245,
     "session_id": "83b8ee5e-8e01-478b-b5df-7a845d73587c",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\nfor s in ['1h30m','45s','2h','0s','1h','1h1m1s']:\n    print(s, parse_duration(s), format_duration(parse_duration(s)), round_trip_ok(s))\nprint(format_duration(5400), format_duration(45), format_duration(0), format_duration(3600))\nprint(round_trip_ok('90m'), round_trip_ok('junk'), round_trip_ok(''), round_trip_ok('30m1 <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\nAll three are in `durations.py` and verified: `parse_duration` handles s in any largest-first combination, `format_duration` gives `5400 \u2192 '1h30m'`, `45 \u2192 '45s'`, `0 \u2192 '0s'`, and `round_trip_ok` returns True for canonical strings, False for non-canonical ones like `'90m'` or `'05s'`.\n\nTwo judgment calls: `parse_duration` raises `ValueError` on malformed input (`''`, `'30m1h'`, `'junk'`), and `round_trip_ok` catches that to return `False` rather than propagating, so it works as a plain validity check."
    }
   ],
   "total_context": 92553,
   "total_cache_creation": 7925,
   "total_cache_read": 83911,
   "total_output": 1866,
   "total_turns": 4,
   "total_tool_calls": 3,
   "total_cost": 0.168324,
   "wall": 26.1,
   "durations_py_lines": 43,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_session",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90363,
     "cache_creation": 7058,
     "cache_read": 82719,
     "fresh_input": 586,
     "output": 1021,
     "turns": 4,
     "cost": 0.1377425,
     "session_id": "626c80d2-79c8-43ad-ba5f-7754c0f04302",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor x in ['1h30m','45s','2h','1h','5m','1h2m3s','2h30s']:\n    print(x, p(x))\nfor bad in ['','30m1h','abc','1d','1h 30m']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('raised:', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration(s)` is in `durations.py:9`. It uses a single anchored regex with optional `<redacted-local-path>` groups, which enforces largest-first ordering for free, and raises `ValueError` on malformed input (`''`, `'30m1h'`, `'1d'`). Verified against the cases above."
    },
    {
     "step": "format",
     "context": 95988,
     "cache_creation": 8707,
     "cache_read": 87273,
     "fresh_input": 8,
     "output": 1024,
     "turns": 4,
     "cost": 0.1563465,
     "session_id": "626c80d2-79c8-43ad-ba5f-7754c0f04302",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p, format_duration as f\nfor n in [0,45,60,300,3600,5400,3723,7230,86399]:\n    print(n, f(n))\nassert all(p(f(n)) == n for n in range(0, 200000, 7))\ntry:\n    f(-1); print('NO RAISE')\nexcept ValueError as e:\n    print('raised:', e)\nprint('roundtrip ok')\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration(seconds)` is in `durations.py:21`. Roundtrip `parse_duration(format_duration(n)) == n` verified for every 7th value from 0 to 200000. Negative input raises `ValueError` since it has no representation in this format \u2014 flagging that since you didn't specify it."
    },
    {
     "step": "roundtrip",
     "context": 76368,
     "cache_creation": 1249,
     "cache_read": 75114,
     "fresh_input": 5,
     "output": 859,
     "turns": 3,
     "cost": 0.071547,
     "session_id": "626c80d2-79c8-43ad-ba5f-7754c0f04302",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m','45s','2h','0s','1h2m3s','23h59m59s']:\n    print(repr(s), r(s))\nfor s in ['0h45s','90m','1h0m','60s',' 45s','','30m1h','abc','1d','1h 30m','045s']:\n    print(repr(s), r(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok(s)` is in `durations.py:41`. It catches `ValueError` from `parse_duration`, so strings that don't parse at all return `False` rather than raising \u2014 that's my reading of \"False otherwise\"; say the word if you'd rather it propagate. Non-canonical but parseable forms (`'90m'`, `'1h0m'`, `' 45s'`) also correctly return `False`."
    }
   ],
   "total_context": 262719,
   "total_cache_creation": 17014,
   "total_cache_read": 245106,
   "total_output": 2904,
   "total_turns": 11,
   "total_tool_calls": 8,
   "total_cost": 0.365636,
   "wall": 48.5,
   "durations_py_lines": 48,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "fresh_session",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113423,
     "cache_creation": 7355,
     "cache_read": 105480,
     "fresh_input": 588,
     "output": 1187,
     "turns": 5,
     "cost": 0.15623299999999998,
     "session_id": "50baa5aa-b9f2-48da-a533-9bc78190c529",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h','30m','1h2m3s','2m30s','0s']:\n    print(repr(s), parse_duration(s))\nfor bad in ['', 'abc', '30m1h', '5', '1h30']:\n    try:\n        parse_duration(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` is in `durations.py:10`. Verified against `1h30m`, `45s`, `2h`, `1h2m3s`, `0s`, and rejects malformed input (`''`, `abc`, `30m1h`, bare `5`, `1h30`) with `ValueError`."
    },
    {
     "step": "format",
     "context": 138347,
     "cache_creation": 5182,
     "cache_read": 132562,
     "fresh_input": 603,
     "output": 1538,
     "turns": 6,
     "cost": 0.156842,
     "session_id": "a3414042-a151-41b1-bded-4a885d946e53",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration, parse_duration\ncases = [0, 1, 45, 60, 3600, 5400, 3601, 3660, 86399, 7325]\nfor n in cases:\n    s = format_duration(n)\n    assert parse_duration(s) == n, (n, s)\n    print(n, '->', s)\ntry:\n    format_duration(-1)\nexcept ValueError as e:\n    print('negative:', e)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` is in `durations.py:29`; all cases round-trip through `parse_duration`. One judgment call: negatives raise `ValueError`, since no duration string can represent them."
    },
    {
     "step": "roundtrip",
     "context": 115564,
     "cache_creation": 5227,
     "cache_read": 109771,
     "fresh_input": 566,
     "output": 1475,
     "turns": 5,
     "cost": 0.1442365,
     "session_id": "d2bb2dde-61b0-46df-b4d5-1dc1cf37d17d",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m','45s','0s','90m','0h','2h','','bogus',' 45s','1h0m30s']:\n    print(repr(s), r(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`round_trip_ok(s)` added at `durations.py:50`. Invalid strings (which make `parse_duration` raise) return False rather than propagating the `ValueError` \u2014 that's the reading of \"and False otherwise\" I went with."
    }
   ],
   "total_context": 367334,
   "total_cache_creation": 17764,
   "total_cache_read": 347813,
   "total_output": 4200,
   "total_turns": 16,
   "total_tool_calls": 13,
   "total_cost": 0.457311,
   "wall": 69.8,
   "durations_py_lines": 59,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "batch2",
   "claude_code_version": "2.1.228"
  },
  {
   "arm": "one_prompt",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 92231,
     "cache_creation": 7721,
     "cache_read": 83793,
     "fresh_input": 717,
     "output": 1619,
     "turns": 4,
     "cost": 0.1600505,
     "session_id": "6d6744ae-4a7f-4ab6-9ad6-02e8001af599",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p, format_duration as f, round_trip_ok as r\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('0s'))\nprint(f(5400), f(45), f(7200), f(0), f(3723), f(3600*2+5))\nprint(r('1h30m'), r('90m'), r('0s'), r('1h0m30s'), r('bogus'), r(''))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "All three functions are in `durations.py` and verified: `parse_duration`, `format_duration`, and `round_trip_ok`.\n\nOne judgment call worth flagging: `parse_duration` raises `ValueError` on malformed input, and `round_trip_ok` catches that and returns `False` (so `round_trip_ok('bogus')` is `False` rather than an exception).\n\nDONE"
    }
   ],
   "total_context": 92231,
   "total_cache_creation": 7721,
   "total_cache_read": 83793,
   "total_output": 1619,
   "total_turns": 4,
   "total_tool_calls": 3,
   "total_cost": 0.160051,
   "wall": 22.5,
   "durations_py_lines": 43,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "one_session",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90596,
     "cache_creation": 7163,
     "cache_read": 82847,
     "fresh_input": 586,
     "output": 1162,
     "turns": 4,
     "cost": 0.1423615,
     "session_id": "597d7e78-9747-4982-a763-3dc5fd38df2d",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor s in ['1h30m','45s','2h','1h2m3s','0s',' 90m ']:\n    print(repr(s), p(s))\nfor bad in ['','abc','30m1h','1d','5']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise', repr(bad))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:20`. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723; invalid input (empty, wrong order like `30m1h`, unknown units, bare numbers) raises `ValueError`. Note `'0s'` returns 0, which is accepted as valid."
    },
    {
     "step": "format",
     "context": 122175,
     "cache_creation": 9448,
     "cache_read": 112717,
     "fresh_input": 10,
     "output": 1453,
     "turns": 5,
     "cost": 0.1872135,
     "session_id": "597d7e78-9747-4982-a763-3dc5fd38df2d",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\nfor n in [5400, 45, 0, 7200, 3723, 60, 3600, 3601, 86399]:\n    print(n, repr(f(n)))\n# round-trip\nbad = [n for n in range(0, 100000) if p(f(n)) != n]\nprint('roundtrip failures:', bad[:5], len(bad))\ntry:\n    f(-1); print('NO RAISE')\nexcept ValueError:\n    print('ok raise on negative')\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration` added at `durations.py:35`. Verified round-trip `parse_duration(format_duration(n)) == n` for every n from 0 to 99,999 \u2014 zero failures. Spot checks: 5400\u2192`1h30m`, 45\u2192`45s`, 0\u2192`0s`, 3601\u2192`1h1s`. Negative input raises `ValueError`, since no such string would parse."
    },
    {
     "step": "roundtrip",
     "context": 78651,
     "cache_creation": 1171,
     "cache_read": 77475,
     "fresh_input": 5,
     "output": 760,
     "turns": 3,
     "cost": 0.06947249999999999,
     "session_id": "597d7e78-9747-4982-a763-3dc5fd38df2d",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m','45s','0s','2h','1h2m3s','0h45s','01h','90m',' 45s ','1h0m','','abc','30m1h','1d']:\n    print(repr(s), r(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok` added at `durations.py:59`. Canonical strings (`1h30m`, `45s`, `0s`) return True; non-canonical but parseable ones (`0h45s`, `01h`, `90m`, `1h0m`, whitespace-padded) return False, as do strings `parse_duration` rejects \u2014 I catch `ValueError` there so the function returns False instead of propagating, which matches \"False otherwise.\""
    }
   ],
   "total_context": 291422,
   "total_cache_creation": 17782,
   "total_cache_read": 273039,
   "total_output": 3375,
   "total_turns": 12,
   "total_tool_calls": 9,
   "total_cost": 0.399047,
   "wall": 53.0,
   "durations_py_lines": 62,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "fresh_session",
   "round": 0,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113352,
     "cache_creation": 7291,
     "cache_read": 105473,
     "fresh_input": 588,
     "output": 1066,
     "turns": 5,
     "cost": 0.1525645,
     "session_id": "2abbe6e4-120e-4191-ad58-d469be01dc13",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_0"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor s in ['1h30m','45s','2h','1h2m3s','90m','0s']:\n    print(s, p(s))\nfor bad in ['','abc','30m1h','5','1h 30m']:\n    try:\n        print(bad, p(bad))\n    except ValueError as e:\n        print('ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "Verified against valid and invalid inputs.\n\nDONE"
    },
    {
     "step": "format",
     "context": 114917,
     "cache_creation": 4998,
     "cache_read": 109318,
     "fresh_input": 601,
     "output": 1510,
     "turns": 5,
     "cost": 0.14267000000000002,
     "session_id": "3875202a-95bf-4199-a801-d72910e45dcc",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_0"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\nfor n in [0,45,60,90,3600,5400,3601,86399,7200,100000]:\n    s=f(n); assert p(s)==n, (n,s,p(s)); print(n,s)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\nRound-trips verified against `parse_duration`. One judgment call: negative input raises `ValueError`, since no accepted string represents it."
    },
    {
     "step": "roundtrip",
     "context": 92484,
     "cache_creation": 4852,
     "cache_read": 87068,
     "fresh_input": 564,
     "output": 1193,
     "turns": 4,
     "cost": 0.12207499999999999,
     "session_id": "d2bf41f2-0a7b-421f-abbd-ca6a20ca7afe",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s','2h','0h0m0s',' 45s','90m','','bogus','01h']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok(s)` is added at the end of `durations.py:44`. One judgment call: inputs `parse_duration` rejects (e.g. `\"\"`, `\"bogus\"`) return `False` instead of propagating the `ValueError`, since a string that can't parse isn't round-trippable."
    }
   ],
   "total_context": 320753,
   "total_cache_creation": 17141,
   "total_cache_read": 301859,
   "total_output": 3769,
   "total_turns": 14,
   "total_tool_calls": 11,
   "total_cost": 0.417309,
   "wall": 70.6,
   "durations_py_lines": 53,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "one_prompt",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 114965,
     "cache_creation": 7753,
     "cache_read": 106493,
     "fresh_input": 719,
     "output": 1521,
     "turns": 5,
     "cost": 0.1692805,
     "session_id": "47076a6d-582a-4d3d-8238-873a0fe43750",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_prompt_1"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p, format_duration as f, round_trip_ok as r\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('0s'))\nprint(f(5400), f(45), f(7200), f(3723), f(0), f(60))\nprint(r('1h30m'), r('45s'), r('0s'), r('90m'), r('1h0m30s'), r('abc'), r(''))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "All three added to `durations.py:8`, `:21`, `:38` and verified: `parse_duration('1h30m')` \u2192 5400, `format_duration(5400)` \u2192 `'1h30m'`, and `round_trip_ok` returns False for non-canonical or invalid input like `'90m'` and `'abc'`.\n\nDONE"
    }
   ],
   "total_context": 114965,
   "total_cache_creation": 7753,
   "total_cache_read": 106493,
   "total_output": 1521,
   "total_turns": 5,
   "total_tool_calls": 4,
   "total_cost": 0.169281,
   "wall": 23.2,
   "durations_py_lines": 43,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "one_session",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90287,
     "cache_creation": 6999,
     "cache_read": 82702,
     "fresh_input": 586,
     "output": 990,
     "turns": 4,
     "cost": 0.136349,
     "session_id": "e5018f38-3101-433f-9a95-d21940a00437",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor s in ['1h30m','45s','2h','1h2m3s','10m']:\n    print(s, p(s))\nfor bad in ['','30m1h','abc','5x']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise', e)\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration` is in `durations.py:10`, verified against `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723, and raising `ValueError` on unknown-unit input."
    },
    {
     "step": "format",
     "context": 120694,
     "cache_creation": 9099,
     "cache_read": 111585,
     "fresh_input": 10,
     "output": 1356,
     "turns": 5,
     "cost": 0.1807325,
     "session_id": "e5018f38-3101-433f-9a95-d21940a00437",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p, format_duration as f\nfor n in [0, 45, 60, 5400, 3600, 3723, 7200, 86399]:\n    print(n, f(n))\n# round-trip\nbad = [n for n in range(0, 200000, 7) if p(f(n)) != n]\nprint('roundtrip failures:', bad[:5], len(bad))\ntry:\n    f(-1); print('NO RAISE')\nexcept ValueError as e:\n    print('ok raise', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration` is in `durations.py:29`. Verified: `5400`\u2192`1h30m`, `45`\u2192`45s`, `0`\u2192`0s`, `3600`\u2192`1h`, `3723`\u2192`1h2m3s`; round-trips through `parse_duration` for every value tested up to 200k, and raises `ValueError` on negatives (no string `parse_duration` accepts could represent them)."
    },
    {
     "step": "roundtrip",
     "context": 77691,
     "cache_creation": 1226,
     "cache_read": 76460,
     "fresh_input": 5,
     "output": 834,
     "turns": 3,
     "cost": 0.071365,
     "session_id": "e5018f38-3101-433f-9a95-d21940a00437",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m','45s','0s','1h','1h2m3s','23h59m59s']:\n    print(repr(s), r(s))\nfor s in ['1h00m','0h45s',' 45s','90m','00s','','abc','30m1h']:\n    print(repr(s), r(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok` is in `durations.py:49`. Canonical strings (`1h30m`, `45s`, `0s`) return True; non-canonical spellings of valid durations (`1h00m`, `90m`, `0h45s`, leading whitespace) return False, as do strings `parse_duration` rejects \u2014 it catches the `ValueError` rather than propagating it, since an unparseable string can't equal any `format_duration` output."
    }
   ],
   "total_context": 288672,
   "total_cache_creation": 17324,
   "total_cache_read": 270747,
   "total_output": 3180,
   "total_turns": 12,
   "total_tool_calls": 9,
   "total_cost": 0.388447,
   "wall": 51.5,
   "durations_py_lines": 54,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "fresh_session",
   "round": 1,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113379,
     "cache_creation": 7319,
     "cache_read": 105472,
     "fresh_input": 588,
     "output": 1171,
     "turns": 5,
     "cost": 0.15546899999999997,
     "session_id": "9f9d5802-a4ea-4b60-b6f3-cf543778c6d5",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_1"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h','30m','1h2m3s','2h30s','0s']:\n    print(s, parse_duration(s))\nfor bad in ['','30x','m30','30m1h','abc']:\n    try:\n        parse_duration(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raised', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` added in `durations.py:10`. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723; invalid or out-of-order input (e.g. `30m1h`, `abc`, `''`) raises `ValueError`."
    },
    {
     "step": "format",
     "context": 138515,
     "cache_creation": 5201,
     "cache_read": 132711,
     "fresh_input": 603,
     "output": 1458,
     "turns": 6,
     "cost": 0.15510649999999998,
     "session_id": "d4524640-2fd3-4893-8e37-f48deb2019ec",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la; find . -name durations.py"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\nfor n in [0,45,60,3600,5400,3661,7200,86399,120,3600*25]:\n    s=f(n); assert p(s)==n, (n,s); print(n,'->',s)\ntry: f(-1)\nexcept ValueError as e: print('neg ok:', e)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` is in `durations.py:26`. Round-trips through `parse_duration` for all values tested; negatives raise `ValueError` since they have no representation in the grammar."
    },
    {
     "step": "roundtrip",
     "context": 115396,
     "cache_creation": 5147,
     "cache_read": 109683,
     "fresh_input": 566,
     "output": 1393,
     "turns": 5,
     "cost": 0.1413425,
     "session_id": "41864c78-e7b0-4bea-bdae-738a6d5df609",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_1"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','0s','2h','90m',' 45s','','xyz','01h','1h0m']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`round_trip_ok(s)` added to `durations.py:48`. Invalid strings raise `ValueError` in `parse_duration`, which it catches and reports as `False` rather than propagating."
    }
   ],
   "total_context": 367290,
   "total_cache_creation": 17667,
   "total_cache_read": 347866,
   "total_output": 4022,
   "total_turns": 16,
   "total_tool_calls": 13,
   "total_cost": 0.451918,
   "wall": 69.3,
   "durations_py_lines": 56,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "one_prompt",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 115128,
     "cache_creation": 7866,
     "cache_read": 106543,
     "fresh_input": 719,
     "output": 1858,
     "turns": 5,
     "cost": 0.17886049999999998,
     "session_id": "b04961a2-21c7-4eb3-98cf-cc4013d2b938",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_prompt_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\nfor s in ['1h30m','45s','2h','1h2m3s','0s']:\n    print(s, parse_duration(s), format_duration(parse_duration(s)), round_trip_ok(s))\nprint(format_duration(5400), format_duration(45), format_duration(0), format_duration(3661))\nprint(round_trip_ok('90m'), round_trip_ok('x'), round_trip_ok(''), round_trip_ok('30m1h'))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\nAdded to `durations.py`:\n- `parse_duration(s)` \u2014 regex `fullmatch` on optional `<redacted-local-path>` groups in that order; raises `ValueError` on anything else (including the empty string and out-of-order units like `30m1h`).\n- `format_duration(seconds)` \u2014 emits only non-zero units, `'0s'` for zero.\n- `round_trip_ok(s)` \u2014 compares the round trip, returning `False` rather than propagating a parse error.\n\nVerified: `5400 \u2192 '1h30m'`, `45 \u2192 '45s'`, `3661 \u2192 '1h1m1s'`, and `'<redacted-local-path>`''` all round-trip `False`."
    }
   ],
   "total_context": 115128,
   "total_cache_creation": 7866,
   "total_cache_read": 106543,
   "total_output": 1858,
   "total_turns": 5,
   "total_tool_calls": 4,
   "total_cost": 0.17886,
   "wall": 30.4,
   "durations_py_lines": 39,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.03s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "one_session",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113327,
     "cache_creation": 7286,
     "cache_read": 105453,
     "fresh_input": 588,
     "output": 1184,
     "turns": 5,
     "cost": 0.1554545,
     "session_id": "8c6077f5-e195-4450-bdda-2d1e85b292ad",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la one_session_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration\nfor s in ['1h30m','45s','2h','1h30m15s','90m','0s']:\n    print(s, parse_duration(s))\nfor bad in ['','abc','30m1h','1x']:\n    try:\n        parse_duration(bad); print('NO ERROR', repr(bad))\n    except ValueError as e:\n        print('ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration(s)` is in `durations.py:10` \u2014 regex-based, accepts any s combination in largest-first order and returns an int; invalid or empty strings raise `ValueError`. Verified against `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h30m15s`\u21925415, plus rejection cases."
    },
    {
     "step": "format",
     "context": 122490,
     "cache_creation": 9585,
     "cache_read": 112896,
     "fresh_input": 9,
     "output": 1342,
     "turns": 5,
     "cost": 0.185893,
     "session_id": "8c6077f5-e195-4450-bdda-2d1e85b292ad",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration\nfor n in [0, 45, 60, 3600, 5400, 5415, 3601, 7200, 86399]:\n    print(n, format_duration(n))\n# round-trip\nbad = [n for n in range(0, 100000) if parse_duration(format_duration(n)) != n]\nprint('roundtrip failures:', bad[:5], len(bad))\ntry:\n    format_duration(-1)\nexcept ValueError as e:\n    print('ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration(seconds)` is in `durations.py:31`, sharing the unit table with `parse_duration`. Round-tripped every value from 0 to 99,999 through `parse_duration(format_duration(n))` with zero mismatches; negative input raises `ValueError`."
    },
    {
     "step": "roundtrip",
     "context": 78859,
     "cache_creation": 1138,
     "cache_read": 77715,
     "fresh_input": 6,
     "output": 909,
     "turns": 3,
     "cost": 0.0729925,
     "session_id": "8c6077f5-e195-4450-bdda-2d1e85b292ad",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','2h','0s','1h30m15s','90m','0h30m',' 45s ','','abc','30m1h']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok(s)` is in `durations.py:49`. Canonical strings return True; non-canonical valid ones (`'90m'`, `'0h30m'`, `' 45s '`) return False, as do invalid strings \u2014 I catch the `ValueError` from `parse_duration` rather than letting it escape, so the predicate always returns a bool."
    }
   ],
   "total_context": 314676,
   "total_cache_creation": 18009,
   "total_cache_read": 296064,
   "total_output": 3435,
   "total_turns": 13,
   "total_tool_calls": 10,
   "total_cost": 0.41434,
   "wall": 59.9,
   "durations_py_lines": 56,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "fresh_session",
   "round": 2,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113368,
     "cache_creation": 7300,
     "cache_read": 105480,
     "fresh_input": 588,
     "output": 1153,
     "turns": 5,
     "cost": 0.154853,
     "session_id": "ea8a8c3e-4e53-439d-a7e5-e7b302c184af",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nfor s in ['1h30m','45s','2h','1h','5m','1h2m3s','0s']:\n    print(s, p(s))\nfor bad in ['','abc','30m1h','1d','-5s']:\n    try: print(bad, p(bad))\n    except ValueError as e: print('ValueError:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration(s)` is in `durations.py:10`. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723. Invalid input (empty, unknown units, wrong order like `30m1h`) raises `ValueError`."
    },
    {
     "step": "format",
     "context": 138351,
     "cache_creation": 5152,
     "cache_read": 132596,
     "fresh_input": 603,
     "output": 1527,
     "turns": 6,
     "cost": 0.15628399999999998,
     "session_id": "04877981-324d-49ca-baeb-0381a3705f6e",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\nfor n in [0,45,60,3600,5400,3661,7200,86399,120]:\n    s=f(n); assert p(s)==n, (n,s); print(n,'->',s)\ntry: f(-1)\nexcept ValueError as e: print('neg ok:',e)\n\""
      }
     ],
     "n_tool_calls": 5,
     "n_bash": 2,
     "reply": "DONE\n\n`format_duration` is in `durations.py:29`; round-trips through `parse_duration` for the cases above, and raises `ValueError` on negatives (which `parse_duration` cannot represent)."
    },
    {
     "step": "roundtrip",
     "context": 115479,
     "cache_creation": 5099,
     "cache_read": 109814,
     "fresh_input": 566,
     "output": 1292,
     "turns": 5,
     "cost": 0.138403,
     "session_id": "7ef294be-f7ce-41da-ae10-650df6a583f3",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_2"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m','45s','0s','2h','90m','0h30m',' 45s','','xyz','1h0m30s','1h30m0s']:\n    print(repr(s), r(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`round_trip_ok(s)` is added at `durations.py:46`. Invalid strings raise `ValueError` inside `parse_duration`, so it catches that and returns `False` rather than propagating \u2014 non-canonical forms like `'90m'`, `'0h30m'`, and `' 45s'` (whitespace stripped on parse) also return `False`."
    }
   ],
   "total_context": 367198,
   "total_cache_creation": 17551,
   "total_cache_read": 347890,
   "total_output": 3972,
   "total_turns": 16,
   "total_tool_calls": 13,
   "total_cost": 0.44954,
   "wall": 65.4,
   "durations_py_lines": 55,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "one_prompt",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "all_three",
     "context": 92010,
     "cache_creation": 7627,
     "cache_read": 83666,
     "fresh_input": 717,
     "output": 1501,
     "turns": 4,
     "cost": 0.156097,
     "session_id": "41f78172-ab44-4795-9e53-93e7a79b13fc",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration, format_duration, round_trip_ok\nprint(parse_duration('1h30m'), parse_duration('45s'), parse_duration('2h'), parse_duration('1h2m3s'), parse_duration('0s'))\nprint(format_duration(5400), format_duration(45), format_duration(7200), format_duration(0), format_duration(3661))\nprint(round_trip_ok('1h30m'), round_trip_ok('45s'), round_trip_ok('90m'), roun <path elided, argument was capped at 400 chars>"
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "All three functions are in `durations.py:8`, `durations.py:23` and `durations.py:38`, and verified: `5400 \u2192 '1h30m'`, `45 \u2192 '45s'`, `0 \u2192 '0s'`; `round_trip_ok('90m')` is False since it normalizes to `'1h30m'`, and invalid input returns False rather than raising.\n\nDONE"
    }
   ],
   "total_context": 92010,
   "total_cache_creation": 7627,
   "total_cache_read": 83666,
   "total_output": 1501,
   "total_turns": 4,
   "total_tool_calls": 3,
   "total_cost": 0.156097,
   "wall": 21.9,
   "durations_py_lines": 40,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "one_session",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 1,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 90375,
     "cache_creation": 7032,
     "cache_read": 82757,
     "fresh_input": 586,
     "output": 1039,
     "turns": 4,
     "cost": 0.1379315,
     "session_id": "da2a1bac-3574-4ac5-831f-27b598a3c26c",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('90m'))\nfor bad in ['', 'abc', '30m1h', '5x', '1h30']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError:\n        print('ok raise', repr(bad))\n\""
      }
     ],
     "n_tool_calls": 3,
     "n_bash": 1,
     "reply": "DONE\n\n`parse_duration` added to `durations.py:11`. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723; out-of-order (`30m1h`), empty, and malformed inputs raise `ValueError`."
    },
    {
     "step": "format",
     "context": 121025,
     "cache_creation": 9146,
     "cache_read": 111869,
     "fresh_input": 10,
     "output": 1403,
     "turns": 5,
     "cost": 0.18251949999999997,
     "session_id": "da2a1bac-3574-4ac5-831f-27b598a3c26c",
     "tool_calls": [
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\nprint(f(5400), f(45), f(0), f(7200), f(3723), f(3600), f(3601))\nbad = [n for n in range(0, 100000) if p(f(n)) != n]\nprint('roundtrip failures:', bad[:5], len(bad))\ntry:\n    f(-1); print('NO RAISE')\nexcept ValueError:\n    print('ok raise on negative')\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 1,
     "reply": "DONE\n\n`format_duration` added at `durations.py:28`. Verified: 5400\u2192`1h30m`, 45\u2192`45s`, 0\u2192`0s`, 3601\u2192`1h1s`; `parse_duration(format_duration(n)) == n` for all n in 0\u201399999; negative input raises `ValueError` (since `parse_duration` can't accept it)."
    },
    {
     "step": "roundtrip",
     "context": 77975,
     "cache_creation": 1297,
     "cache_read": 76673,
     "fresh_input": 5,
     "output": 968,
     "turns": 3,
     "cost": 0.0755315,
     "session_id": "da2a1bac-3574-4ac5-831f-27b598a3c26c",
     "tool_calls": [
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok as r\nfor s in ['1h30m','45s','2h','0s','1h2m3s']:\n    print(repr(s), r(s))\nfor s in ['90m','0h45s',' 45s','01h','1h0m','30m1h','abc','']:\n    print(repr(s), r(s))\n\""
      }
     ],
     "n_tool_calls": 2,
     "n_bash": 1,
     "reply": "DONE\n\n`round_trip_ok` added at `durations.py:47`. Canonical strings (`1h30m`, `45s`, `0s`) return True; non-canonical-but-parseable (`90m`, `1h0m`, `01h`, `' 45s'`) return False.\n\nOne judgment call worth flagging: for strings `parse_duration` rejects (`abc`, `''`), the composition would raise rather than compare, so I catch `ValueError` and return False \u2014 that keeps it a total predicate. If you'd rather it propagate the error, it's a two-line change."
    }
   ],
   "total_context": 289375,
   "total_cache_creation": 17475,
   "total_cache_read": 271299,
   "total_output": 3410,
   "total_turns": 12,
   "total_tool_calls": 9,
   "total_cost": 0.395983,
   "wall": 55.2,
   "durations_py_lines": 55,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  },
  {
   "arm": "fresh_session",
   "round": 3,
   "status": "ok",
   "session_control_ok": true,
   "distinct_session_ids": 3,
   "every_call_ran_bash": true,
   "passed": true,
   "calls": [
    {
     "step": "parse",
     "context": 113357,
     "cache_creation": 7285,
     "cache_read": 105484,
     "fresh_input": 588,
     "output": 1173,
     "turns": 5,
     "cost": 0.155185,
     "session_id": "b389042a-9cc7-44fc-9a66-e22b21e95e03",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls -la fresh_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Write",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import parse_duration as p\nprint(p('1h30m'), p('45s'), p('2h'), p('1h2m3s'), p('90m'))\nfor bad in ['', 'abc', '30m1h', '5', '1h30']:\n    try:\n        p(bad); print('NO RAISE', repr(bad))\n    except ValueError as e:\n        print('ok raise:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\n`parse_duration` is in `durations.py:10` \u2014 regex-based, requires largest-unit-first ordering, and raises `ValueError` on misordered input. Verified: `1h30m`\u21925400, `45s`\u219245, `2h`\u21927200, `1h2m3s`\u21923723."
    },
    {
     "step": "format",
     "context": 114777,
     "cache_creation": 4988,
     "cache_read": 109188,
     "fresh_input": 601,
     "output": 1623,
     "turns": 5,
     "cost": 0.14533,
     "session_id": "fe8ab6ab-3a54-4bc1-967e-9fe2a382a27e",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import format_duration as f, parse_duration as p\ncases = [0, 1, 45, 59, 60, 90, 3600, 5400, 3601, 7322, 86399, 100000]\nfor n in cases:\n    s = f(n)\n    assert p(s) == n, (n, s, p(s))\n    print(n, '->', s)\ntry:\n    f(-1)\nexcept ValueError as e:\n    print('neg ok:', e)\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\nAdded `format_duration` to `durations.py:26`. It divmods through the existing `_UNIT_SECONDS` table, skips zero-valued units, and falls back to `'0s'` when everything is zero. Verified round-tripping through `parse_duration` on a spread of values (`5400 -> '1h30m'`, `45 -> '45s'`, `3601 -> '1h1s'`, `0 -> '0s'`).\n\nOne judgment call worth flagging: the spec didn't cover negative input, and since `parse_duration` can never produce a negative, silently emitting an unparseable string would be worse \u2014 so negatives raise `ValueError`. Say the word if you'd rather it clamp or format a leading si"
    },
    {
     "step": "roundtrip",
     "context": 114833,
     "cache_creation": 4896,
     "cache_read": 109371,
     "fresh_input": 566,
     "output": 1233,
     "turns": 5,
     "cost": 0.1346765,
     "session_id": "eb42f268-c5f0-41a8-815a-7496b78fd645",
     "tool_calls": [
      {
       "tool": "Bash",
       "arg": "ls fresh_session_3"
      },
      {
       "tool": "Read",
       "arg": "durations.py"
      },
      {
       "tool": "Edit",
       "arg": "durations.py"
      },
      {
       "tool": "Bash",
       "arg": "python3 -c \"\nfrom durations import round_trip_ok\nfor s in ['1h30m','45s','2h','0s','1h0m','01h',' 45s','','5x','1h30m0s']:\n    print(repr(s), round_trip_ok(s))\n\""
      }
     ],
     "n_tool_calls": 4,
     "n_bash": 2,
     "reply": "DONE\n\nNote: `parse_duration` raises `ValueError` on unparseable input, so I caught it and return `False` there (e.g. `round_trip_ok(\"5x\")` \u2192 `False` rather than raising). Inputs that parse but aren't canonical, like `\"1h0m\"` or `\" 45s\"`, also return `False`."
    }
   ],
   "total_context": 342967,
   "total_cache_creation": 17169,
   "total_cache_read": 324043,
   "total_output": 4029,
   "total_turns": 15,
   "total_tool_calls": 12,
   "total_cost": 0.435191,
   "wall": 64.9,
   "durations_py_lines": 51,
   "pytest_tail": "...                                                                      [100%]\n3 passed in 0.01s\n",
   "batch": "reverify229",
   "claude_code_version": "2.1.229"
  }
 ],
 "reverification_2_1_229": {
  "date": "2026-08-13",
  "why": "Claude Code moved from 2.1.228 to 2.1.229 the morning after publication, and every figure in this corpus is pinned to a version. Four fresh rounds per arm were run on 2.1.229 with the identical harness (same file sha256 for the hidden suite, same fixture control verdicts, both asserted before merging) and appended here rather than replacing anything. Runs carry claude_code_version so the two can always be separated again.",
  "n_rounds": 4,
  "all_passed": true,
  "session_control_ok": true,
  "medians": {
   "one_prompt": {
    "2.1.228": 103828,
    "2.1.229": 103598
   },
   "one_session": {
    "2.1.228": 274436,
    "2.1.229": 290398
   },
   "fresh_session": {
    "2.1.228": 344408,
    "2.1.229": 355082
   }
  },
  "separation_holds_on_229": {
   "total_context": {
    "one_session": true,
    "fresh_session": true
   },
   "total_cost": {
    "one_session": true,
    "fresh_session": true
   },
   "total_turns": {
    "one_session": true,
    "fresh_session": true
   },
   "total_tool_calls": {
    "one_session": true,
    "fresh_session": true
   }
  },
  "paired_fresh_vs_session_on_229": {
   "total_context": {
    "fresh_dearer": 4,
    "of": 4,
    "sign_p": 0.0625
   },
   "total_cost": {
    "fresh_dearer": 4,
    "of": 4,
    "sign_p": 0.0625
   },
   "total_turns": {
    "fresh_dearer": 4,
    "of": 4,
    "sign_p": 0.0625
   },
   "total_tool_calls": {
    "fresh_dearer": 4,
    "of": 4,
    "sign_p": 0.0625
   }
  },
  "within_run_step3_minus_step1_on_229": {
   "one_session": {
    "median_step3_minus_step1": -12498,
    "cheaper_in": 4,
    "of": 4
   },
   "fresh_session": {
    "median_step3_minus_step1": 1746,
    "cheaper_in": 1,
    "of": 4
   }
  },
  "turn_fit": {
   "2.1.228": {
    "intercept": 2025,
    "tokens_per_turn": 23116,
    "r2": 0.9972
   },
   "2.1.229": {
    "intercept": 1467,
    "tokens_per_turn": 23274,
    "r2": 0.9957
   },
   "slope_change_pct": 0.69
  },
  "verdict": "Every published claim reproduces. The separation of one_prompt from both multi-prompt arms holds on all four measures, fresh stays dearer than resumed in 4 of 4 paired rounds, the resumed arm's third step stays cheaper than its own first in 4 of 4, and the per-turn rate moves by under 1%. The multi-prompt medians rose a few percent, and their turn counts rose with them, which is what the turn model predicts rather than a change in the effect."
 }
}