diff --git a/CLAUDE.md b/CLAUDE.md
index 06c5427..f888db1 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -104,7 +104,7 @@ Se `references/architecture/recommended-mcp-servers.md` for detaljer.
 
 | Event | Script | Formål |
 |-------|--------|--------|
-| SessionStart | `session-start-context.mjs` | Viser aktive utredninger, KB-ferskhet, onboarding-status + AI Act-frister |
+| SessionStart | `session-start-context.mjs` | Viser aktive utredninger, KB-ferskhet, onboarding-status, skill- + kurs-signaler (Spor C) + AI Act-frister |
 | Stop | `stop-assessment-reminder.mjs` | Påminnelse om ucommittede vurderinger, neste steg |
 
 > Secrets scanning consolidated to llm-security plugin.
diff --git a/docs/development.md b/docs/development.md
index 9e4754a..abfbae4 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -66,6 +66,27 @@ Legacy (deprecated):
 bash scripts/kb-staleness-check.sh  # mtime-basert, upålitelig etter git clone
 ```
 
+### Kurs-deteksjon (Spor C / C3 — Learn Platform API, opt-in)
+
+Et parallelt, uavhengig spor fra sitemap-discoveren: oppdage at Microsoft har publisert **nye** eller **endrede** treningskurs (modules + learning paths) i produktene KB-en dekker, slik at operatøren kan vurdere om temaet bør dekkes. Et kurs er et *signal*, ikke en doc-side — det auto-ingestes aldri. Full spec: [`c3-course-detection-plan.md`](c3-course-detection-plan.md).
+
+**To-stegs-mønster (samme invariant som `discover-new-urls`):**
+
+1. **Deteksjon (Claude-fri, opt-in, Node-script).** `detect-courses.mjs` leser tre Entra-creds fra macOS Keychain, henter token, paginerer Platform API (`/api/v1/modules` + `/learning-paths`) med produkt- og `updatedAt.gt`-filter, diff-er mot `data/course-registry.json` (detektorens egen sporings-state), og skriver **kun** to private filer: `data/course-detection-report.json` (kandidater) + oppdatert `course-registry.json`. Importerer **aldri** `saveDecisions` — skriver hverken `skills/` eller `decisions.json`.
+
+   ```bash
+   node scripts/kb-update/detect-courses.mjs              # default data-dir
+   node scripts/kb-update/detect-courses.mjs --data-dir DIR  # omdiriger IO (tester)
+   ```
+
+   Fail-soft: mangler creds → `status:"skipped"` + exit 0; vedvarende nettverksfeil → `status:"error"` + exit 0. Opt-in inni opt-in: steget kjøres kun av scheduleren når `include_course_detection: true` (default `false`) — sett nøkkelen manuelt i `~/.claude/ms-ai-architect/ms-ai-architect.local.md`.
+
+2. **SessionStart-surfacing (read-only).** `session-start-context.mjs` leser `course-detection-report.json` og viser en one-liner via `summarizeCourses` («Kurs-signaler: N nye / M endrede kurs i dekkede produkter. Kjør /architect:kb-update») — speiler skill-signaler-blokka. `removed` er kun et informasjonssignal i rapporten, aldri en surfacet lead (spec §4.2). Hooken spawner ingenting for kurs-sporet.
+
+3. **Gate (operatør, Claude-i-loop).** `/architect:kb-update` §3c leser rapporten, presenterer nye/endrede leads, og skriver godkjente leads til den UID-nøklede `courses`-kolleksjonen i `decisions.json` (via `recordCourseLead`). `--dry-run` viser leads uten å skrive. **Strukturell invariant:** ingen apply-path leser `courses` → et godkjent kurs-lead trigger aldri fetch/transform/KB-skriving.
+
+Slug→skill-mapping er config i `domain-taxonomy.json` (`course_products`), ikke hardkoding. `last_full_enum`-kadens (≥30 d) styrer når `removed` beregnes (kun full-enumerering — aldri inkrementelt).
+
 ### E2E-regresjonstester
 ```bash
 # Kjør alle E2E-suiter
diff --git a/hooks/scripts/session-start-context.mjs b/hooks/scripts/session-start-context.mjs
index 153c007..63f8d9a 100644
--- a/hooks/scripts/session-start-context.mjs
+++ b/hooks/scripts/session-start-context.mjs
@@ -10,6 +10,7 @@ import {
   loadScheduleConfig,
   shouldRunDetection,
   summarizeSkillLifecycle,
+  summarizeCourses,
 } from '../../scripts/kb-update/lib/detection-schedule.mjs';
 import {
   resolveOrgDir,
@@ -188,6 +189,20 @@ if (existsSync(skillReportPath)) {
   }
 }
 
+// Course-detection signals (Spor C / C3.6) — read-only one-liner; never spawns.
+// A lead is a signal that a topic exists, not auto-ingest: surfacing it here
+// invites the operator to run /architect:kb-update §3c, which gates the lead
+// into the courses ledger. Mirrors the skill-signaler block above.
+const courseReportPath = join(pluginRoot, 'scripts', 'kb-update', 'data', 'course-detection-report.json');
+if (existsSync(courseReportPath)) {
+  try {
+    const courseSummary = summarizeCourses(JSON.parse(readFileSync(courseReportPath, 'utf8')));
+    if (courseSummary) parts.push(`${courseSummary}. Kjør /architect:kb-update`);
+  } catch {
+    // Ignore — advisory only
+  }
+}
+
 if (nearestDeadline) {
   parts.push(`EU AI Act: ${nearestDeadline.daysLeft} dager til ${nearestDeadline.label}. Kjør /architect:classify`);
 }
diff --git a/scripts/kb-update/lib/detection-schedule.mjs b/scripts/kb-update/lib/detection-schedule.mjs
index f517485..b1876af 100644
--- a/scripts/kb-update/lib/detection-schedule.mjs
+++ b/scripts/kb-update/lib/detection-schedule.mjs
@@ -233,3 +233,26 @@ export function summarizeSkillLifecycle(report, opts = {}) {
   if (stale > 0) parts.push(`${stale} stale`);
   return parts.length ? `Skill-signaler: ${parts.join(', ')}` : null;
 }
+
+/**
+ * Build a compact one-liner summarizing course-detection leads (Spor C / C3.6)
+ * for the SessionStart hook. Pure; tolerant of partial/missing reports. Mirrors
+ * summarizeSkillLifecycle. Surfaces only NEW + UPDATED leads in covered
+ * products; `removed` is an informational rapport-signal (spec §4.2), never a
+ * surfaced lead. Returns null when there is nothing worth surfacing (0 new + 0
+ * updated, a skipped/error report, or a malformed shape).
+ * @param {object|null} report  parsed course-detection-report.json
+ * @returns {string|null}
+ */
+export function summarizeCourses(report) {
+  if (!report || typeof report !== 'object') return null;
+  if (report.status && report.status !== 'ok') return null;
+  const counts = report.counts ?? {};
+  const fresh = Number(counts.new) || 0;
+  const changed = Number(counts.updated) || 0;
+
+  const parts = [];
+  if (fresh > 0) parts.push(`${fresh} nye`);
+  if (changed > 0) parts.push(`${changed} endrede`);
+  return parts.length ? `Kurs-signaler: ${parts.join(' / ')} kurs i dekkede produkter` : null;
+}
diff --git a/tests/kb-update/test-detection-schedule.test.mjs b/tests/kb-update/test-detection-schedule.test.mjs
index 296b2d0..cb2552b 100644
--- a/tests/kb-update/test-detection-schedule.test.mjs
+++ b/tests/kb-update/test-detection-schedule.test.mjs
@@ -25,6 +25,7 @@ import {
   shouldRunDetection,
   selectDetectionSteps,
   summarizeSkillLifecycle,
+  summarizeCourses,
   daysSinceLastPoll,
 } from '../../scripts/kb-update/lib/detection-schedule.mjs';
 import { writeScheduleConfig } from '../../scripts/kb-update/write-schedule-config.mjs';
@@ -369,6 +370,65 @@ test('summarizeSkillLifecycle — tolerates a missing/partial report shape', ()
   assert.equal(summarizeSkillLifecycle(null, { threshold: 7.0 }), null);
 });
 
+// ===========================================================================
+// (C2) summarizeCourses — one-liner surfaced at session start (Spor C / C3.6)
+// ===========================================================================
+// Mirrors summarizeSkillLifecycle: a pure one-liner over a parsed
+// course-detection-report.json, surfacing NEW + UPDATED course leads in
+// covered products. `removed` is an informational rapport-signal (spec §4.2),
+// NOT a surfaced lead, so it must never make this return non-null on its own.
+
+const COURSE_REPORT_OK = {
+  generated_at: '2026-06-23T12:00:00Z',
+  status: 'ok',
+  skipped_reason: null,
+  new: [{ uid: 'm1' }, { uid: 'm2' }],
+  updated: [{ uid: 'm3' }],
+  removed: [],
+  counts: { new: 2, updated: 1, removed: 0 },
+};
+
+test('summarizeCourses — surfaces new + updated leads in the canonical one-liner', () => {
+  const s = summarizeCourses(COURSE_REPORT_OK);
+  assert.match(s, /Kurs-signaler:/);
+  assert.match(s, /2 nye/);
+  assert.match(s, /1 endrede/);
+  assert.match(s, /kurs i dekkede produkter/);
+});
+
+test('summarizeCourses — only-new and only-updated each render alone', () => {
+  const onlyNew = summarizeCourses({ status: 'ok', counts: { new: 3, updated: 0, removed: 0 } });
+  assert.match(onlyNew, /3 nye kurs i dekkede produkter/);
+  assert.doesNotMatch(onlyNew, /endrede/);
+  const onlyUpdated = summarizeCourses({ status: 'ok', counts: { new: 0, updated: 4, removed: 0 } });
+  assert.match(onlyUpdated, /4 endrede kurs i dekkede produkter/);
+  assert.doesNotMatch(onlyUpdated, /nye/);
+});
+
+test('summarizeCourses — zero new + zero updated returns null (nothing to surface)', () => {
+  assert.equal(summarizeCourses({ status: 'ok', counts: { new: 0, updated: 0, removed: 0 } }), null);
+});
+
+test('summarizeCourses — removed-only is informational, not a surfaced lead (spec §4.2)', () => {
+  assert.equal(
+    summarizeCourses({ status: 'ok', counts: { new: 0, updated: 0, removed: 5 } }),
+    null,
+  );
+});
+
+test('summarizeCourses — skipped/error reports surface nothing', () => {
+  const skipped = { status: 'skipped', skipped_reason: 'creds', counts: { new: 0, updated: 0, removed: 0 } };
+  const errored = { status: 'error', skipped_reason: 'network', counts: { new: 0, updated: 0, removed: 0 } };
+  assert.equal(summarizeCourses(skipped), null);
+  assert.equal(summarizeCourses(errored), null);
+});
+
+test('summarizeCourses — tolerates a missing/partial report shape', () => {
+  assert.equal(summarizeCourses({}, {}), null);
+  assert.equal(summarizeCourses(null), null);
+  assert.equal(summarizeCourses({ status: 'ok' }), null); // no counts
+});
+
 // ===========================================================================
 // (D) STRUCTURAL ToS GUARANTEE — detection is Claude-free
 // ===========================================================================