diff --git a/backend/server.js b/backend/server.js
index 0cceb72..e00f4d9 100644
--- a/backend/server.js
+++ b/backend/server.js
@@ -886,6 +886,32 @@ app.post('/api/scenarios/:id/time', (req, res) => {
   res.json({ ok: true });
 });
 
+// POST /api/progress/record — Phase 2A addition. Records a scenario outcome WITHOUT
+// re-running validation. Exists because scenario validation itself must run against the
+// student's own live cluster (inside their ephemeral Lab container), but the canonical
+// progress record needs to live here, on the persistent identity instance — the Gateway
+// calls this after a real validate/answer already succeeded against the student's Lab, to
+// relay the outcome. See docs/PHASE2A_GATEWAY_AND_STUDENT_FLOW.md "Progress relay."
+app.post('/api/progress/record', (req, res) => {
+  const { scenario_id, status } = req.body || {};
+  if (!scenario_id || !['completed', 'in_progress'].includes(status)) {
+    return res.status(400).json({ error: 'scenario_id and a valid status are required' });
+  }
+  const studentId = getStudentId(req);
+  const progress = loadProgress(studentId);
+  const prev = progress[scenario_id] || { attempts: 0 };
+  progress[scenario_id] = {
+    ...prev,
+    status,
+    attempts: (prev.attempts || 0) + 1,
+    last_validated: new Date().toISOString(),
+    completed_at: status === 'completed' ? new Date().toISOString() : prev.completed_at,
+  };
+  saveProgress(studentId, progress);
+  touchStudent(studentId);
+  res.json({ ok: true });
+});
+
 // GET /api/progress — full progress summary
 app.get('/api/progress', (req, res) => {
   const scenarios = loadScenarios();