diff --git a/scripts/seed-digest-notifications.mjs b/scripts/seed-digest-notifications.mjs
index 0877fb9a1..ba16740f1 100644
--- a/scripts/seed-digest-notifications.mjs
+++ b/scripts/seed-digest-notifications.mjs
@@ -454,10 +454,23 @@ async function generateAISummary(stories, rule) {
   if (!AI_DIGEST_ENABLED) return null;
   if (!stories || stories.length === 0) return null;
 
-  const { data: prefs } = await fetchUserPreferences(rule.userId, rule.variant ?? 'full');
+  // rule.aiDigestEnabled (from alertRules) is the user's explicit opt-in for
+  // AI summaries. userPreferences is a SEPARATE table (SPA app settings blob:
+  // watchlist, airports, panels). A user can have alertRules without having
+  // ever saved userPreferences — or under a different variant. Missing prefs
+  // must NOT silently disable the feature the user just enabled; degrade to
+  // a non-personalized summary instead.
+  //   error: true  = transient fetch failure (network, non-OK HTTP, env missing)
+  //   error: false = the (userId, variant) row genuinely does not exist
+  // Both cases degrade to a non-personalized summary, but log them distinctly
+  // so transient fetch failures are visible in observability.
+  const { data: prefs, error: prefsFetchError } = await fetchUserPreferences(rule.userId, rule.variant ?? 'full');
   if (!prefs) {
-    console.log(`[digest] No preferences for ${rule.userId} — skipping AI summary`);
-    return null;
+    console.log(
+      prefsFetchError
+        ? `[digest] Prefs fetch failed for ${rule.userId} — generating non-personalized AI summary`
+        : `[digest] No stored preferences for ${rule.userId} — generating non-personalized AI summary`,
+    );
   }
   const ctx = extractUserContext(prefs);
   const profile = formatUserProfile(ctx, rule.variant ?? 'full');
diff --git a/tests/user-context.test.mjs b/tests/user-context.test.mjs
new file mode 100644
index 000000000..37cec4688
--- /dev/null
+++ b/tests/user-context.test.mjs
@@ -0,0 +1,103 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import { createRequire } from 'node:module';
+
+const require = createRequire(import.meta.url);
+const { extractUserContext, formatUserProfile } = require('../scripts/lib/user-context.cjs');
+
+// These helpers feed the digest AI executive summary prompt. The digest
+// cron fetches userPreferences via a Convex relay endpoint that returns
+// literal `null` when the (userId, variant) row doesn't exist. A user can
+// have alertRules (with aiDigestEnabled: true) but no userPreferences
+// document — for example, a notification rule enabled before the user
+// ever synced the SPA, or under a different variant. Missing preferences
+// MUST NOT silently disable the AI summary; we degrade to a generic
+// "Variant: full" profile and still call the LLM.
+//
+// These tests lock in that contract so `extractUserContext(null)` and
+// `formatUserProfile(ctx, variant)` remain null-safe.
+
+describe('extractUserContext null-safety', () => {
+  const empty = {
+    tickers: [],
+    airports: [],
+    airlines: [],
+    frameworkName: null,
+    enabledPanels: [],
+    disabledFeeds: [],
+  };
+
+  it('returns empty context for null', () => {
+    assert.deepEqual(extractUserContext(null), empty);
+  });
+
+  it('returns empty context for undefined', () => {
+    assert.deepEqual(extractUserContext(undefined), empty);
+  });
+
+  it('returns empty context for empty object', () => {
+    assert.deepEqual(extractUserContext({}), empty);
+  });
+
+  it('returns empty context for non-object (string)', () => {
+    assert.deepEqual(extractUserContext('not an object'), empty);
+  });
+
+  it('extracts tickers from wm-market-watchlist-v1', () => {
+    const ctx = extractUserContext({
+      'wm-market-watchlist-v1': [
+        { symbol: 'AAPL' },
+        { symbol: 'TSLA' },
+        { notASymbol: true },
+      ],
+    });
+    assert.deepEqual(ctx.tickers, ['AAPL', 'TSLA']);
+  });
+
+  it('extracts airports and airlines from aviation:watchlist:v1', () => {
+    const ctx = extractUserContext({
+      'aviation:watchlist:v1': {
+        airports: ['JFK', 'LHR'],
+        airlines: ['UAL', 'BA'],
+      },
+    });
+    assert.deepEqual(ctx.airports, ['JFK', 'LHR']);
+    assert.deepEqual(ctx.airlines, ['UAL', 'BA']);
+  });
+});
+
+describe('formatUserProfile null-safety', () => {
+  it('handles an entirely empty context (no crash, no empty lines)', () => {
+    const emptyCtx = extractUserContext(null);
+    const profile = formatUserProfile(emptyCtx, 'full');
+    assert.equal(profile, 'Variant: full');
+  });
+
+  it('handles empty context for every variant value', () => {
+    for (const variant of ['full', 'tech', 'finance', 'commodity', 'happy']) {
+      const profile = formatUserProfile(extractUserContext(null), variant);
+      assert.equal(profile, `Variant: ${variant}`);
+    }
+  });
+
+  it('includes watchlist entries when present', () => {
+    const ctx = extractUserContext({
+      'wm-market-watchlist-v1': [{ symbol: 'AAPL' }, { symbol: 'TSLA' }],
+    });
+    const profile = formatUserProfile(ctx, 'finance');
+    assert.match(profile, /^Variant: finance$/m);
+    assert.match(profile, /^Watches: AAPL, TSLA$/m);
+  });
+
+  it('always includes the Variant line even with rich context', () => {
+    const ctx = extractUserContext({
+      'wm-market-watchlist-v1': [{ symbol: 'AAPL' }],
+      'aviation:watchlist:v1': { airports: ['JFK'], airlines: ['UAL'] },
+    });
+    const profile = formatUserProfile(ctx, 'full');
+    assert.match(profile, /^Variant: full$/m);
+    assert.match(profile, /Watches: AAPL/);
+    assert.match(profile, /Monitors airports: JFK/);
+    assert.match(profile, /Monitors airlines: UAL/);
+  });
+});