diff --git a/backend/utils/notes-preview.js b/backend/utils/notes-preview.js
new file mode 100644
index 0000000..7efaa74
--- /dev/null
+++ b/backend/utils/notes-preview.js
@@ -0,0 +1,26 @@
+function computeNotesPreview(notes) {
+  if (!notes || notes.trim() === '') {
+    return { has_notes: false, notes_preview: null };
+  }
+
+  const firstParagraph = notes.split(/\n\n/)[0];
+
+  const stripped = firstParagraph
+    .replace(/^#{1,6}\s+/gm, '')       // headers
+    .replace(/\*\*(.+?)\*\*/g, '$1')   // bold
+    .replace(/\*(.+?)\*/g, '$1')       // italic with *
+    .replace(/_(.+?)_/g, '$1')         // italic with _
+    .replace(/\[([^\]]+)\]\([^)]+\)/g, '$1') // links
+    .replace(/^[-*+]\s+/gm, '')        // list markers
+    .replace(/\n/g, ' ')               // collapse remaining newlines
+    .replace(/\s+/g, ' ')              // collapse whitespace
+    .trim();
+
+  const truncated = stripped.length > 150
+    ? stripped.slice(0, 150) + '...'
+    : stripped;
+
+  return { has_notes: true, notes_preview: truncated };
+}
+
+module.exports = { computeNotesPreview };
diff --git a/tests/api/session-notes.test.js b/tests/api/session-notes.test.js
new file mode 100644
index 0000000..20f0fc9
--- /dev/null
+++ b/tests/api/session-notes.test.js
@@ -0,0 +1,64 @@
+const { computeNotesPreview } = require('../../backend/utils/notes-preview');
+
+describe('computeNotesPreview', () => {
+  test('returns has_notes false and null preview for null input', () => {
+    const result = computeNotesPreview(null);
+    expect(result).toEqual({ has_notes: false, notes_preview: null });
+  });
+
+  test('returns has_notes false and null preview for empty string', () => {
+    const result = computeNotesPreview('');
+    expect(result).toEqual({ has_notes: false, notes_preview: null });
+  });
+
+  test('returns first paragraph as preview', () => {
+    const notes = 'First paragraph here.\n\nSecond paragraph here.';
+    const result = computeNotesPreview(notes);
+    expect(result.has_notes).toBe(true);
+    expect(result.notes_preview).toBe('First paragraph here.');
+  });
+
+  test('strips markdown bold formatting', () => {
+    const notes = '**Bold text** and more';
+    const result = computeNotesPreview(notes);
+    expect(result.notes_preview).toBe('Bold text and more');
+  });
+
+  test('strips markdown italic formatting', () => {
+    const notes = '*Italic text* and _also italic_';
+    const result = computeNotesPreview(notes);
+    expect(result.notes_preview).toBe('Italic text and also italic');
+  });
+
+  test('strips markdown links', () => {
+    const notes = 'Check [this link](http://example.com) out';
+    const result = computeNotesPreview(notes);
+    expect(result.notes_preview).toBe('Check this link out');
+  });
+
+  test('strips markdown headers', () => {
+    const notes = '## Header text';
+    const result = computeNotesPreview(notes);
+    expect(result.notes_preview).toBe('Header text');
+  });
+
+  test('strips markdown list markers', () => {
+    const notes = '- Item one\n- Item two';
+    const result = computeNotesPreview(notes);
+    expect(result.notes_preview).toBe('Item one Item two');
+  });
+
+  test('truncates to 150 characters with ellipsis', () => {
+    const notes = 'A'.repeat(200);
+    const result = computeNotesPreview(notes);
+    expect(result.notes_preview).toHaveLength(153); // 150 + '...'
+    expect(result.notes_preview.endsWith('...')).toBe(true);
+  });
+
+  test('does not truncate text at or under 150 characters', () => {
+    const notes = 'A'.repeat(150);
+    const result = computeNotesPreview(notes);
+    expect(result.notes_preview).toHaveLength(150);
+    expect(result.notes_preview).not.toContain('...');
+  });
+});