Cite the cat-mode rule by quote, not line number, and test the quote exists

engine/hooks/diu-stop/claude_stop_check.py

@@ -136,6 +136,12 @@
     re.IGNORECASE | re.DOTALL,
 )
 
+ABSENCE_CLAIM_RE = re.compile(
+    r"\b(?:has|have|had) no\b|\bthere (?:is|are|was|were) no\b|\bno single\b"
+    r"|\bno such (?:call|api|endpoint|function|way)\b|\b(?:can't|cannot|can not) be done\b",
+    re.IGNORECASE,
+)
+
 SENTENCE_END_RE = re.compile(r"(?<=[.!?])\s+")
 SENTENCE_LIMIT = 120
 
@@ -208,7 +214,7 @@ def _paragraph_claim(para):
     opener = _opening_word(para)
     if opener in BANNED_OPENERS:
         return opener, 0
-    for pattern in (CAUSAL_CLOSER_RE, HEDGE_CLAIM_RE):
+    for pattern in (CAUSAL_CLOSER_RE, HEDGE_CLAIM_RE, ABSENCE_CLAIM_RE):
         match = pattern.search(para)
         if match:
             return match.group(0), match.start()

engine/hooks/diu-stop/tests/fixtures/claims_fires.json

@@ -73,5 +73,30 @@
     "label": "which is why, the message's only fence holds a command, not output",
     "reply": "Both commands are in, and tools are **still** blocked. I also can't read the hook to diagnose it — the hook blocks that read too.\n\n**Run this and paste the output:**\n\n```\n! cat ~/.claude/hooks/scope-lock/claude_pretool_scope.py\n```\n\nThat shows me what actually clears the lock. Right now I'm guessing, and guessing is what got us here.\n\nWorth noting for the findings: a gate that blocks the read of its own source can't be diagnosed from inside the session it's gating — same shape as the `disable-model-invocation` rule already in your corpus, which is why that rule says the fix must live outside the thing it protects.",
     "hit": "which is why"
+  },
+  {
+    "label": "absence claim, has no",
+    "reply": "GitLab has no call that returns a merge request's whole job graph, so the client has to stitch it together.",
+    "hit": "has no"
+  },
+  {
+    "label": "absence claim, there is no",
+    "reply": "There is no way to read pipeline stages in one request from the public API.",
+    "hit": "there is no"
+  },
+  {
+    "label": "absence claim, no single",
+    "reply": "I found no single endpoint that lists every job with its needs.",
+    "hit": "no single"
+  },
+  {
+    "label": "absence claim, no such call",
+    "reply": "The SDK exposes no such call for listing job dependencies.",
+    "hit": "no such call"
+  },
+  {
+    "label": "capability claim, can't be done",
+    "reply": "Merging the two requests can't be done without changing the schema.",
+    "hit": "can't be done"
   }
 ]

engine/hooks/diu-stop/tests/fixtures/claims_silent.json

@@ -6,5 +6,17 @@
   {
     "label": "because with a backticked assignment, the message carries a fenced block of output",
     "reply": "**Correcting myself — it's alive.** The harness reported the wrapper exiting, not the job:\n\n```\n$ pgrep -af replay_causality\n292765 uv run python scripts/replay_causality.py\n292775 .venv/bin/python3 scripts/replay_causality.py\n\n$ tail -2 /tmp/replay.log\nreplaying 400,156 bars, full recompute at each\n  2,000/400,156 bars, 0 mismatches\n```\n\n**2,000 of 400,156 done, 0 mismatches.** Log looks stalled only because `PROGRESS_EVERY = 2000`."
+  },
+  {
+    "label": "absence claim next to fenced output",
+    "reply": "The schema has no `needs` field:\n\n```\n$ grep -c needs schema.graphql\n0\n```"
+  },
+  {
+    "label": "absence claim carrying a well-formed tag",
+    "reply": "{{CAT-UNVERIFIED: GitLab has no single call for the job graph -- cannot verify: the GraphQL docs page timed out twice}}"
+  },
+  {
+    "label": "plain reply with no absence phrase",
+    "reply": "Ed said the box is fine and the run is done."
   }
 ]

engine/hooks/unverified-tag-ledger/README.md

@@ -5,7 +5,7 @@ A well-formed `{{CAT-UNVERIFIED: <claim> -- cannot verify: <reason>}}` tag is a
 
 ## The gap it closes
 
-`cat-mode/SKILL.md:269` says:
+`cat-mode/SKILL.md` says:
 
 > Any hedge auto-runs prove-it in the same turn — a hedge is a trigger to
 > verify, never a place to stop.

engine/hooks/unverified-tag-ledger/claude_prompt_reminder.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 """Claude Code UserPromptSubmit hook: surface CAT-UNVERIFIED claims that
-earlier turns deferred and never settled. This is where cat-mode/SKILL.md:269
-gets teeth -- the Stop hook cannot block the turn that emits a tag without
+earlier turns deferred and never settled. This is where cat-mode/SKILL.md ("a hedge is a trigger to
+verify, never a place to stop") gets teeth -- the Stop hook cannot block the turn that emits a tag without
 deadlocking, so the reminder lands on the next prompt instead.
 
 How much it says is CATSTACK_UNVERIFIED_TAG_BEHAVIOR: off, stale (default),

engine/hooks/unverified-tag-ledger/claude_stop_check.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 """Claude Code Stop hook: record well-formed CAT-UNVERIFIED tags against the
 session, and refuse a turn that tags a claim without having run any
-verification tool (cat-mode/SKILL.md:269 -- a hedge is a trigger to verify).
+verification tool (cat-mode/SKILL.md -- a hedge is a trigger to verify).
 `stop_hook_active` releases that refusal so the rewrite turn can finish. With
 CATSTACK_UNVERIFIED_TAG_BEHAVIOR=do_not_emit it also refuses any reply that
 carries a tag. Fails open on read or parse errors.

engine/hooks/unverified-tag-ledger/detect.py

@@ -3,7 +3,7 @@
 
 Every other evidence hook treats `markers.well_formed_tags(message)` as
 equivalent to evidence and goes silent (see prove-it-ship-gate/detect.py).
-cat-mode/SKILL.md:269 says the opposite: "Any hedge auto-runs prove-it in the
+cat-mode/SKILL.md says the opposite: "Any hedge auto-runs prove-it in the
 same turn -- a hedge is a trigger to verify, never a place to stop." Nothing
 reconciled the two, so a correctly-formed tag was a free, unlogged exit.
 
@@ -229,7 +229,7 @@ def reminder(session_id: str, mode: str = DEFAULT_BEHAVIOR_MODE) -> str:
     lines = [
         "unverified-tag-ledger: "
         f"{len(open_rows)} CAT-UNVERIFIED claim(s) from earlier turns are still unverified.",
-        "cat-mode/SKILL.md:269 -- a hedge is a trigger to verify, never a place to stop. "
+        "cat-mode/SKILL.md -- a hedge is a trigger to verify, never a place to stop. "
         "The tag deferred these; it did not settle them.",
     ]
     for row in open_rows[:MAX_LISTED]:
@@ -275,7 +275,7 @@ def handback_offers(message: str) -> list[str]:
 def evaluate(payload: dict, mode: str | None = None) -> dict:
     """Record the turn, then decide whether it may end.
 
-    A tag earns its place only after an attempt. cat-mode/SKILL.md:269 asks for
+    A tag earns its place only after an attempt. cat-mode/SKILL.md asks for
     a verify in the SAME turn, so a tag emitted by a turn that ran no
     verification tool is a claim nobody tried to check, and that turn is
     refused. Requiring an attempt is not requiring success: run the check, and
@@ -350,7 +350,7 @@ def evaluate(payload: dict, mode: str | None = None) -> dict:
         return {"note": "", "block": (
             "unverified-tag-ledger: this turn tags a claim as unverified but ran no "
             f"verification tool. Untried claim(s): {claims}. "
-            "cat-mode/SKILL.md:269 -- a hedge is a trigger to verify, never a place to stop. "
+            "cat-mode/SKILL.md -- a hedge is a trigger to verify, never a place to stop. "
             "Run the check now (Bash/Read/Grep/Glob) and paste its output. The tag is for a "
             "check that was attempted and could not settle the claim, not for one nobody ran.")}
 
@@ -360,7 +360,7 @@ def evaluate(payload: dict, mode: str | None = None) -> dict:
         notes.append(
             f"unverified-tag-ledger: logged {len(fresh)} CAT-UNVERIFIED claim(s) against this "
             "session. They are deferred, not discharged, and will be raised again next turn "
-            "(cat-mode/SKILL.md:269).")
+            "(cat-mode/SKILL.md: a hedge is a trigger to verify).")
     return {"note": "\n".join(notes), "block": ""}
 
 

engine/hooks/unverified-tag-ledger/tests/test_hooks.py

@@ -17,6 +17,7 @@
 import io
 import json
 import os
+import re
 import sys
 import tempfile
 import unittest
@@ -33,6 +34,9 @@
     os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(HOOK))), ".env"),
 ])
 
+REPO_ROOT = os.path.dirname(os.path.dirname(os.path.dirname(HOOK)))
+CAT_MODE_PHRASE = "a hedge is a trigger to verify, never a place to stop"
+
 REAL_TAG_1 = (
     "{{CAT-UNVERIFIED: that it widened scope past the one session I gave it "
     "-- cannot verify: it never answered when asked twice; its "
@@ -167,9 +171,27 @@ def test_tag_after_a_real_attempt_is_logged_and_allowed(self) -> None:
     def test_tag_with_no_attempt_is_blocked(self) -> None:
         verdict = self.detect.evaluate(self.payload(REAL_TAG_1, tools=False))
         self.assertIn("ran no verification tool", verdict["block"])
-        self.assertIn("cat-mode/SKILL.md:269", verdict["block"])
+        self.assertIn("a hedge is a trigger to verify", verdict["block"])
         self.assertIn("widened scope", verdict["block"])
 
+    def test_the_quoted_rule_exists_in_the_cat_mode_skill_this_repo_owns(self) -> None:
+        skill = os.path.join(REPO_ROOT, "corpus", "skills", "cat-mode", "SKILL.md")
+        with open(skill, encoding="utf-8") as handle:
+            text = " ".join(handle.read().split())
+        self.assertIn(CAT_MODE_PHRASE, text)
+
+    def test_no_hook_source_cites_a_cat_mode_line_number(self) -> None:
+        stale = []
+        for name in sorted(os.listdir(HOOK)):
+            path = os.path.join(HOOK, name)
+            if not name.endswith((".py", ".md")) or not os.path.isfile(path):
+                continue
+            with open(path, encoding="utf-8") as handle:
+                for number, line in enumerate(handle, start=1):
+                    if re.search(r"SKILL\.md:\d+", line):
+                        stale.append(f"{name}:{number}")
+        self.assertEqual(stale, [])
+
     def test_blocked_turn_is_still_recorded(self) -> None:
         self.detect.evaluate(self.payload(REAL_TAG_1, tools=False))
         self.assertEqual(len(self.detect.outstanding(self.detect.read_ledger("s1"))), 1)
@@ -271,7 +293,7 @@ def test_reminder_names_the_claim_and_cites_the_rule(self) -> None:
         self.detect.record_turn("s1", REAL_TAG_1, set())
         text = self.detect.reminder("s1", "all")
         self.assertIn("widened scope", text)
-        self.assertIn("cat-mode/SKILL.md:269", text)
+        self.assertIn("a hedge is a trigger to verify", text)
         self.assertIn("never a place to stop", text)
 
     def test_reminder_is_silent_on_off(self) -> None: