judge: LLM-as-judge triage for canary failures (advisory only)

Add harness/judge.py and scripts/triage.py. The judge reads the latest
loop run from logs/runs.jsonl, finds canary failures (exact_match=False
but fields/linter passed), and asks GPT-5 to classify each as
"regression", "variant", or "unclear" with CMOS 18 section citations.

CRITICAL: verdicts are ADVISORY ONLY. They are written to
logs/triage.jsonl and never feed back into the loop scalar. Using the
judge as ground truth would let the formatter-LLM optimize against a
judge-LLM from the same model family, inviting shared-bias drift.

Design:
- harness/judge.py: Verdict dataclass, build_judge_prompt, parse_verdict
  (handles code fences and normalizes unknown labels to "unclear"),
  judge() with caller-injection seam matching cmos.formatter. Uses the
  same _is_reasoning_model branching to skip temperature for gpt-5/o*.
  Judge model is separately overridable via CMOS_JUDGE_MODEL env var
  (defaults to OPENAI_MODEL, which defaults to gpt-5).
- scripts/triage.py: CLI that walks runs.jsonl, locates a target run
  (default: latest), filters canary failures, calls judge on each,
  appends a verdict record to logs/triage.jsonl. --dry-run available
  for offline testing. Exits 0 with a note when there are no failures.

Tests: 6 new unit tests covering prompt building, JSON parsing
(including code-fence stripping and unknown-label normalization), and
caller injection. No real API calls in the test suite.

Validated on iter 3's run (canary 0.286, 10 failures):
- 8 correctly flagged as regressions, each with a cited CMOS section
  (14.72, 14.76, 14.128, 14.190, 14.206, 14.212, 14.267, ...).
- 2 flagged as variants: "Kindle" vs "Kindle edition" (CMOS 14.159–
  14.161 allows flexibility) and "The New Yorker" vs "New Yorker"
  (CMOS 14.191 — leading "The" is optional). These surface that the
  formatter's current rules 17 and 18 are stricter than CMOS strictly
  requires; documenting here but not acting on yet.
This commit is contained in:
cmos dev
2026-04-10 22:09:08 -04:00
parent fe5e071066
commit 1b11a03a0b
3 changed files with 332 additions and 0 deletions
+132
View File
@@ -0,0 +1,132 @@
"""LLM-as-judge for canary failures — advisory triage only.
This module is NOT part of the hot autoresearch loop. It exists to help a
human (or script) classify canary-exact-match failures: was the formatter
genuinely wrong (a "regression"), or did it produce a CMOS-18-legal
variant that happens to differ from the frozen canonical string (a
"variant")?
Judge verdicts are advisory and stored as data in ``logs/triage.jsonl``.
They never feed back into the scoring harness — if they did, we'd be
optimizing the formatter against a judge built on the same model family,
which invites shared-bias drift.
Caller-injection pattern matches ``cmos.formatter`` so tests can run
without touching the network.
"""
from __future__ import annotations
import json
import os
import re
from dataclasses import dataclass
from typing import Callable
from dotenv import load_dotenv
JUDGE_MODEL = os.environ.get("CMOS_JUDGE_MODEL", os.environ.get("OPENAI_MODEL", "gpt-5"))
Caller = Callable[[str, str], str]
JUDGE_SYSTEM_PROMPT = """\
You are a strict Chicago Manual of Style, 18th edition, notes-and-bibliography \
adjudicator. You will be given TWO strings: an EXPECTED bibliography entry \
(the frozen canonical) and a CANDIDATE bibliography entry (what a formatter \
produced). Your job is to decide whether the candidate is:
- "regression": the candidate contains a real CMOS-18 error OR has dropped, \
added, or corrupted a piece of source metadata (author, title, publisher, \
year, page range, DOI, URL, edition, etc.) relative to the expected. Examples: \
a missing "et al.", a wrong year, "Second edition" instead of "2nd ed.", \
dropping "Effective" from a web policy date, adding a place of publication \
(CMOS 18 does not require one), using a hyphen where CMOS 9.61 prescribes an \
en-dash, omitting the "Podcast," format label.
- "variant": the candidate differs from the expected only in ways that are \
explicitly CMOS-18-legal. Examples include harmless spelling out vs. \
abbreviation that CMOS treats as equivalent, genuinely optional fields, \
equivalent punctuation choices where CMOS 18 allows either, or differences in \
whitespace. A variant is NOT a regression; the formatter is still correct.
- "unclear": you cannot determine from the strings alone whether the \
difference is a regression or a legal variant. Use this sparingly.
Respond with ONLY a JSON object of the form:
{"label": "regression" | "variant" | "unclear", "reasoning": "one or two sentences citing the specific CMOS 18 rule that applies"}
No preamble, no markdown fences, no commentary outside the JSON.
"""
@dataclass
class Verdict:
label: str
reasoning: str
def build_judge_prompt(expected: str, candidate: str, cmos_type: str) -> str:
return (
f"Source type: {cmos_type}\n\n"
f"EXPECTED:\n{expected}\n\n"
f"CANDIDATE:\n{candidate}\n\n"
f"Classify the candidate per CMOS 18 rules. Respond with the JSON object described in the system prompt."
)
_CODE_FENCE_RE = re.compile(r"^```(?:json)?\s*(.*?)\s*```$", re.DOTALL)
def parse_verdict(raw: str) -> Verdict:
"""Parse a judge response into a Verdict. Tolerates code fences and
normalizes unknown labels to 'unclear'."""
stripped = raw.strip()
m = _CODE_FENCE_RE.match(stripped)
if m:
stripped = m.group(1).strip()
try:
data = json.loads(stripped)
except json.JSONDecodeError:
return Verdict(label="unclear", reasoning=f"could not parse judge output: {raw[:200]}")
label = str(data.get("label", "unclear")).lower()
if label not in ("regression", "variant", "unclear"):
label = "unclear"
reasoning = str(data.get("reasoning", ""))
return Verdict(label=label, reasoning=reasoning)
def _is_reasoning_model(model: str) -> bool:
prefixes = ("gpt-5", "o1", "o3", "o4")
return any(model.startswith(p) for p in prefixes)
def _openai_judge_caller(system: str, user: str) -> str:
load_dotenv()
from openai import OpenAI
client = OpenAI()
kwargs: dict = {
"model": JUDGE_MODEL,
"messages": [
{"role": "system", "content": system},
{"role": "user", "content": user},
],
}
if not _is_reasoning_model(JUDGE_MODEL):
kwargs["temperature"] = 0
response = client.chat.completions.create(**kwargs)
return response.choices[0].message.content or ""
def judge(
expected: str,
candidate: str,
cmos_type: str,
caller: Caller | None = None,
) -> Verdict:
"""Ask the judge to classify a (expected, candidate) pair."""
call = caller or _openai_judge_caller
user = build_judge_prompt(expected, candidate, cmos_type)
raw = call(JUDGE_SYSTEM_PROMPT, user)
return parse_verdict(raw)
+119
View File
@@ -0,0 +1,119 @@
"""Triage canary failures from the most recent loop run using an LLM judge.
Reads ``logs/runs.jsonl``, finds the latest run, identifies exemplars whose
``exact_match`` is False (canary failures), calls the judge on each, and
appends verdicts to ``logs/triage.jsonl``.
The judge output is ADVISORY — it never feeds into the loop scalar.
Verdicts are for a human to review ("is this a variant or a real
regression?") after the fact.
Usage:
uv run python scripts/triage.py
uv run python scripts/triage.py --run-index -1 # last run (default)
uv run python scripts/triage.py --run-index -2 # second-last
uv run python scripts/triage.py --dry-run # no API calls
If there are no canary failures in the target run, the script prints a
note and exits 0 without calling the judge.
"""
from __future__ import annotations
import argparse
import json
import sys
from datetime import datetime, timezone
from pathlib import Path
sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
from harness.judge import JUDGE_MODEL, Verdict, judge # noqa: E402
from harness.score import load_exemplars # noqa: E402
def _dry_run_judge(expected: str, candidate: str, cmos_type: str) -> Verdict:
return Verdict(label="unclear", reasoning="(dry run — judge not called)")
def main() -> int:
ap = argparse.ArgumentParser(description=__doc__)
ap.add_argument("--runs-log", default="logs/runs.jsonl")
ap.add_argument("--triage-log", default="logs/triage.jsonl")
ap.add_argument("--exemplars", default="exemplars")
ap.add_argument("--run-index", type=int, default=-1, help="which run to triage")
ap.add_argument("--dry-run", action="store_true", help="do not call the judge")
args = ap.parse_args()
runs_path = Path(args.runs_log)
if not runs_path.exists():
print(f"no runs log at {runs_path}", file=sys.stderr)
return 2
with runs_path.open() as fh:
runs = [json.loads(line) for line in fh if line.strip()]
if not runs:
print("runs log is empty", file=sys.stderr)
return 2
try:
run = runs[args.run_index]
except IndexError:
print(f"run index {args.run_index} out of range (have {len(runs)} runs)", file=sys.stderr)
return 2
# Map exemplar name → canonical expected_bibliography and type.
ex_map = {ex.name: ex for ex in load_exemplars(Path(args.exemplars))}
failures = [r for r in run["per_exemplar"] if r["canary"] and not r["exact_match"]]
if not failures:
print(f"no canary failures in run at {run['timestamp']} — nothing to triage")
return 0
judge_fn = _dry_run_judge if args.dry_run else judge
print(f"triaging {len(failures)} canary failure(s) from run {run['timestamp']}")
print(f"judge model: {'(dry run)' if args.dry_run else JUDGE_MODEL}")
print()
triage_path = Path(args.triage_log)
triage_path.parent.mkdir(parents=True, exist_ok=True)
with triage_path.open("a") as out:
for r in failures:
name = r["name"]
ex = ex_map.get(name)
if ex is None:
print(f" [{name}] exemplar not found on disk, skipping")
continue
expected = ex.expected_bibliography
candidate = r["candidate"]
verdict = judge_fn(expected, candidate, ex.type)
entry = {
"triage_timestamp": datetime.now(timezone.utc).isoformat(),
"run_timestamp": run["timestamp"],
"exemplar": name,
"cmos_type": ex.type,
"expected": expected,
"candidate": candidate,
"judge_label": verdict.label,
"judge_reasoning": verdict.reasoning,
"judge_model": None if args.dry_run else JUDGE_MODEL,
}
out.write(json.dumps(entry) + "\n")
icon = {
"regression": "!!",
"variant": "ok",
"unclear": "??",
}.get(verdict.label, "??")
print(f" [{icon}] {name}: {verdict.label}")
if verdict.reasoning:
print(f" {verdict.reasoning}")
print()
print(f"verdicts appended to {triage_path}")
return 0
if __name__ == "__main__":
raise SystemExit(main())
+81
View File
@@ -0,0 +1,81 @@
"""Tests for harness/judge.py — LLM-as-judge for canary failures.
The judge is an advisory triage tool, not part of the hot loop. It
classifies canary-mismatch candidates as either "regression" (the
formatter made a real CMOS error) or "variant" (the formatter produced a
CMOS-legal rendering that happens to differ from the frozen canonical
string).
These tests use a fake caller — no real API calls.
"""
import json
from harness.judge import Verdict, build_judge_prompt, judge, parse_verdict
def test_build_judge_prompt_includes_both_strings_and_type():
prompt = build_judge_prompt(
expected="Yu, Charles. *Interior Chinatown*. Pantheon Books, 2020.",
candidate="Yu, Charles. *Interior Chinatown*. New York: Pantheon Books, 2020.",
cmos_type="book",
)
assert "Yu, Charles" in prompt
assert "New York" in prompt
assert "book" in prompt.lower()
assert "cmos" in prompt.lower() or "chicago" in prompt.lower()
def test_parse_verdict_extracts_label_and_reasoning():
raw = json.dumps(
{"label": "regression", "reasoning": "place of publication added; CMOS 18 drops it."}
)
v = parse_verdict(raw)
assert v.label == "regression"
assert "place of publication" in v.reasoning
def test_parse_verdict_accepts_label_only():
raw = json.dumps({"label": "variant", "reasoning": ""})
v = parse_verdict(raw)
assert v.label == "variant"
assert v.reasoning == ""
def test_parse_verdict_normalizes_unexpected_labels_to_unclear():
# A judge that returns something other than regression/variant should
# end up labeled 'unclear' so the human reviewer knows to look at it.
raw = json.dumps({"label": "maybe", "reasoning": "..."})
v = parse_verdict(raw)
assert v.label == "unclear"
def test_parse_verdict_handles_code_fences():
# LLM sometimes wraps JSON in ``` fences; parse_verdict should survive.
raw = '```json\n{"label": "variant", "reasoning": "abbreviated publisher"}\n```'
v = parse_verdict(raw)
assert v.label == "variant"
assert "abbreviated" in v.reasoning
def test_judge_uses_injected_caller():
captured = {}
def fake_caller(system: str, user: str) -> str:
captured["system"] = system
captured["user"] = user
return json.dumps(
{"label": "regression", "reasoning": "inserted place of publication"}
)
v = judge(
expected="Yu, Charles. *Interior Chinatown*. Pantheon Books, 2020.",
candidate="Yu, Charles. *Interior Chinatown*. New York: Pantheon Books, 2020.",
cmos_type="book",
caller=fake_caller,
)
assert isinstance(v, Verdict)
assert v.label == "regression"
assert "place of publication" in v.reasoning
assert "18" in captured["system"] # CMOS 18 grounding in the system prompt
assert "Yu, Charles" in captured["user"]