frontend/src/api/lessons.ts

@@ -65,6 +65,10 @@ export interface LessonListRow {
   tags: string[];
   when_to_apply?: string;
   snippet?: string;
+  /** Surfaced-vs-opened for this lesson. Always present on a listing from
+   *  this door, zero-filled where nothing has been recorded — absent only
+   *  when a row came from somewhere else. */
+  usage?: RecordUsage;
   shared?: boolean;
   owner?: string | null;
 }

frontend/src/views/LessonDetailView.vue

@@ -24,6 +24,7 @@ import { apiErrorMessage } from "@/api/client";
 import { deleteLesson, getLesson, type Lesson } from "@/api/lessons";
 import ConfirmDialog from "@/components/ConfirmDialog.vue";
 import TagPill from "@/components/TagPill.vue";
+import UsageBadge from "@/components/UsageBadge.vue";
 import { useToastStore } from "@/stores/toast";
 import { renderMarkdown } from "@/utils/markdown";
 
@@ -99,7 +100,19 @@ onMounted(load);
         <p class="ld-trigger-text">{{ lesson.when_to_apply }}</p>
       </section>
 
-      <h1 class="ld-what">{{ lesson.what }}</h1>
+      <div class="ld-what-row">
+        <h1 class="ld-what">{{ lesson.what }}</h1>
+        <!-- Lessons collected surfaced-vs-opened from the day the slot shipped
+             and showed it nowhere (#4196). It belongs here above anywhere
+             else: the reading that matters is almost never "delete this", it
+             is "the trigger is keyed to a situation nobody is in", and the
+             place to act on that is the lesson you are already looking at. -->
+        <UsageBadge
+          :usage="lesson.usage"
+          noun="lesson"
+          dead-weight-advice="Repeatedly offered and never opened usually means the trigger fires on the wrong situation — re-key `when_to_apply` rather than deleting the claim."
+        />
+      </div>
 
       <div
         v-if="insightHtml"
@@ -210,6 +223,13 @@ onMounted(load);
 }
 .ld-trigger-text { margin: 0; font-size: 0.98rem; line-height: 1.5; }
 
+.ld-what-row {
+  display: flex;
+  align-items: baseline;
+  gap: var(--fs-space-2);
+  flex-wrap: wrap;
+}
+
 .ld-what {
   margin: 0 0 1.25rem;
   font-size: 1.25rem;

src/scribe/mcp/tools/lessons.py

@@ -17,7 +17,7 @@ from scribe.services import lessons as lessons_svc
 from scribe.services import systems as systems_svc
 from scribe.services import trash as trash_svc
 from scribe.mcp.tools import systems as systems_tools
-from scribe.services.note_usage import record_pulled
+from scribe.services.note_usage import empty_usage, record_pulled, usage_for_notes
 
 
 # The payload shape lives in the service (`lesson_to_dict`), shared with the
@@ -61,6 +61,11 @@ async def list_lessons(
         project_id=project_id or None,
     )
     labelled = await access_svc.label_shared_items(uid, items)
+    # One aggregate for the page, like the snippet listing — surfaced-vs-opened
+    # per lesson (#4196). An agent listing lessons can see which of its own
+    # triggers are firing and which are not, which is the reading that leads to
+    # `update_lesson` rather than to a second lesson about the same failure.
+    usage = await usage_for_notes([int(it["id"]) for it in labelled])
     rows = [
         {
             "id": it["id"], "title": it["title"], "tags": it.get("tags", []),
@@ -68,6 +73,7 @@ async def list_lessons(
             # Projected by `_note_to_item` straight off the `data` mirror —
             # absent when the row carries none, rather than an empty string.
             "when_to_apply": it.get("when_to_apply", ""),
+            "usage": usage.get(int(it["id"]), empty_usage()),
             **({"shared": True, "owner": it.get("owner")} if it.get("shared") else {}),
         }
         for it in labelled
@@ -203,6 +209,12 @@ async def get_lesson(lesson_id: int, project_id: int = 0) -> dict:
     # retrieval as any other note, so a getter that records nothing would leave
     # the kind permanently at zero pulls — reading as dead weight beside kinds
     # that merely had a counter (#2476, the repeat of #2245).
+    # Read BEFORE the pull is recorded, so the number an agent is shown is the
+    # one that was true when it asked — otherwise every first read of a lesson
+    # reports a pull that is its own.
+    out["usage"] = (await usage_for_notes([int(note.id)])).get(
+        int(note.id), empty_usage()
+    )
     record_pulled(
         user_id=uid, note_id=int(note.id),
         source="mcp_get_lesson", project_id=project_id,

src/scribe/routes/lessons.py

@@ -72,10 +72,21 @@ async def list_lessons_route():
         offset=offset,
         project_id=project_id,
     )
-    return jsonify({
-        "lessons": await label_shared_items(uid, items),
-        "total": total,
-    })
+    items = await label_shared_items(uid, items)
+    # One aggregate for the whole page — a per-row lookup would be N+1 by
+    # construction. Every row gets the key, zero-filled, so the UI renders
+    # "never surfaced" rather than treating a missing field as a state.
+    #
+    # Lessons were the one kind collecting this and showing it nowhere (#4196).
+    # The counts matter more here than on a snippet: the promotion question a
+    # lesson eventually raises — does this bind? — is answered by repeatedly
+    # surfaced AND repeatedly opened, and the far commoner reading of the same
+    # row is that the trigger fires on the wrong situation, which `update_lesson`
+    # exists to fix.
+    usage = await usage_for_notes([int(it["id"]) for it in items])
+    for it in items:
+        it["usage"] = usage.get(int(it["id"]), empty_usage())
+    return jsonify({"lessons": items, "total": total})
 
 
 @lessons_bp.route("/taught-by/<int:record_id>", methods=["GET"])

tests/test_lesson_usage_surface.py

@@ -0,0 +1,189 @@
+"""A lesson's surfaced-vs-opened counts reach a reader (#4196).
+
+The lesson slot has recorded usage since it shipped, and until this nothing
+showed it. `get_lesson`'s REST door attached it; the list did not, neither MCP
+door did, and no view rendered it — so the one kind whose central question is
+"is this trigger firing on the right situation" was the one kind whose answer
+was unreadable.
+
+WHY THE COUNTS MATTER MORE HERE THAN ON A SNIPPET. #4196 asks whether a lesson
+repeatedly followed should become a rule, and names the trap: raw frequency
+cannot tell "this should bind" from "this trigger is too broad", which is the
+commoner reading. Surfaced-AND-opened can. Neither question is answerable by
+anything that cannot see the numbers, which is why this is the first step and
+not the threshold.
+
+NO THRESHOLD IS ASSERTED ANYWHERE HERE, deliberately. At the time of writing
+the corpus is 10 lessons with 7 recorded surfacings and 3 opens; a promotion
+rule fitted to that would be fitting noise, and `UsageBadge` already declines
+to render a verdict on fewer than three surfacings for the same reason.
+"""
+import inspect
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from scribe.mcp.tools import lessons as lesson_tools
+from scribe.services.note_usage import empty_usage
+
+
+def _rows():
+    return [
+        {"id": 7, "title": "a", "tags": [], "snippet": "", "when_to_apply": "x"},
+        {"id": 9, "title": "b", "tags": [], "snippet": "", "when_to_apply": "y"},
+    ]
+
+
+@pytest.mark.asyncio
+async def test_the_mcp_listing_carries_usage_for_every_row():
+    """Zero-filled, not omitted. A missing key would make the reader treat
+    "never surfaced" and "not reported" as the same thing, which is the
+    distinction the whole readout exists to keep."""
+    used = {7: {**empty_usage(), "surfaced_count": 5, "pull_count": 2}}
+    with (
+        patch.object(lesson_tools, "current_user_id", return_value=1),
+        patch.object(lesson_tools.knowledge_svc, "query_knowledge",
+                     new=AsyncMock(return_value=(_rows(), 2))),
+        patch.object(lesson_tools.access_svc, "label_shared_items",
+                     new=AsyncMock(side_effect=lambda _uid, items: items)),
+        patch.object(lesson_tools, "usage_for_notes",
+                     new=AsyncMock(return_value=used)),
+    ):
+        out = await lesson_tools.list_lessons()
+
+    by_id = {r["id"]: r for r in out["lessons"]}
+    assert by_id[7]["usage"]["surfaced_count"] == 5
+    assert by_id[7]["usage"]["pull_count"] == 2
+    # The row nobody has surfaced still carries the key.
+    assert by_id[9]["usage"] == empty_usage()
+
+
+@pytest.mark.asyncio
+async def test_the_listing_asks_for_usage_once_for_the_whole_page():
+    """One aggregate, not one lookup per row — the snippet listing's own
+    comment calls a per-row read N+1 by construction, and a lesson list is the
+    same shape."""
+    reader = AsyncMock(return_value={})
+    with (
+        patch.object(lesson_tools, "current_user_id", return_value=1),
+        patch.object(lesson_tools.knowledge_svc, "query_knowledge",
+                     new=AsyncMock(return_value=(_rows(), 2))),
+        patch.object(lesson_tools.access_svc, "label_shared_items",
+                     new=AsyncMock(side_effect=lambda _uid, items: items)),
+        patch.object(lesson_tools, "usage_for_notes", new=reader),
+    ):
+        await lesson_tools.list_lessons()
+
+    assert reader.await_count == 1
+    assert sorted(reader.await_args.args[0]) == [7, 9]
+
+
+@pytest.mark.asyncio
+async def test_get_lesson_reads_the_count_before_recording_its_own_pull():
+    """Otherwise the first read of a lesson reports a pull that is its own.
+
+    `get_lesson` records a pull on every open — it has to, or the kind sits
+    permanently at zero and reads as dead weight. That makes the ORDER load
+    bearing in a way it is not for kinds that only count.
+    """
+    order: list[str] = []
+    note = MagicMock(id=7, user_id=1)
+
+    async def _usage_read(ids):
+        order.append("read")
+        return {7: {**empty_usage(), "surfaced_count": 4, "pull_count": 1}}
+
+    with (
+        patch.object(lesson_tools, "current_user_id", return_value=1),
+        patch.object(lesson_tools.lessons_svc, "get_lesson",
+                     new=AsyncMock(return_value=note)),
+        patch.object(lesson_tools, "_to_dict", return_value={"id": 7}),
+        patch.object(lesson_tools.access_svc, "describe_provenance",
+                     new=AsyncMock(return_value={})),
+        patch.object(lesson_tools, "usage_for_notes", new=_usage_read),
+        patch.object(lesson_tools, "record_pulled",
+                     side_effect=lambda **_kw: order.append("pull")),
+    ):
+        out = await lesson_tools.get_lesson(7)
+
+    assert order == ["read", "pull"], (
+        "the pull was recorded before the count was read, so the number the "
+        "caller is shown includes the read that produced it"
+    )
+    assert out["usage"]["pull_count"] == 1
+
+
+# ── the REST door, on structure (rule 167) ───────────────────────────────────
+#
+# Its siblings in test_lesson_rest_door.py are source guards for the same
+# reason: the route is decorated and returns a Quart response, so driving it
+# means standing up the app. What matters here is reachable from the source
+# and falsifiable from it — an aggregate rather than a per-row read, and the
+# same read-then-record order the MCP door is pinned to above.
+
+
+def _route_source(name: str) -> str:
+    from scribe.routes import lessons as routes
+
+    src = inspect.getsource(routes)
+    start = src.index(f"async def {name}(")
+    nxt = src.find("\n@lessons_bp.route", start)
+    return src[start:nxt if nxt > 0 else len(src)]
+
+
+def test_the_rest_listing_reads_usage_once_for_the_page():
+    """A per-row lookup would be N+1 by construction — the listing's own
+    comment says so, and this is what makes that comment checkable."""
+    src = _route_source("list_lessons_route")
+    assert src.count("usage_for_notes(") == 1
+    # The one call is not inside the loop that assigns the rows.
+    call = src.index("usage_for_notes(")
+    assign = src.index('["usage"]')
+    assert call < assign
+
+
+def test_every_rest_row_carries_the_key_even_at_zero():
+    """"Never surfaced" is a state the UI renders; a missing field is not."""
+    src = _route_source("list_lessons_route")
+    assert "empty_usage()" in src, (
+        "a row with no recorded usage would come back without the key, and a "
+        "reader cannot tell that from a reporting failure"
+    )
+
+
+def test_the_rest_detail_door_also_reads_before_it_records():
+    """Two doors that disagree about what the number counts are worse than
+    one door that is wrong, because only one of them looks wrong."""
+    src = _route_source("get_lesson_route")
+    assert src.index("usage_for_notes(") < src.index("record_pulled(")
+
+
+def test_these_guards_can_fail():
+    """Rule 167: falsify the shape they assert against, so a guard that has
+    quietly stopped describing anything cannot pass by describing nothing."""
+    src = _route_source("list_lessons_route")
+    assert "def list_lessons_route" in src
+    assert "def get_lesson_route" not in src, "the slice ran past its route"
+
+
+def test_the_detail_view_renders_the_badge_rather_than_respelling_it():
+    """Snippet #3460: reach for UsageBadge and pass the kind's own advice; a
+    view's scoped re-spelling of `.usage-tag` is what that component replaced.
+
+    The advice is the kind-specific half. For a lesson it points at the
+    trigger, not at deletion — a lesson nobody opens is usually keyed to a
+    situation nobody is in, which is `update_lesson`'s own words and the
+    reading #4196 calls the commoner one.
+    """
+    view = (Path(__file__).resolve().parents[1]
+            / "frontend/src/views/LessonDetailView.vue").read_text()
+    assert "UsageBadge" in view
+    assert "usage-tag" not in view, "re-spelled the chip instead of reusing it"
+
+    key = 'dead-weight-advice="'
+    start = view.index(key) + len(key)
+    advice = view[start:view.index('"', start)]
+    assert "when_to_apply" in advice, (
+        f"the dead-weight advice does not point at the trigger: {advice!r}"
+    )