diff --git a/src/ClaudeDo.Data/Repositories/DailyNoteRepository.cs b/src/ClaudeDo.Data/Repositories/DailyNoteRepository.cs
new file mode 100644
index 0000000..2d1d94f
--- /dev/null
+++ b/src/ClaudeDo.Data/Repositories/DailyNoteRepository.cs
@@ -0,0 +1,59 @@
+using ClaudeDo.Data.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace ClaudeDo.Data.Repositories;
+
+public sealed class DailyNoteRepository
+{
+    private readonly ClaudeDoDbContext _context;
+
+    public DailyNoteRepository(ClaudeDoDbContext context) => _context = context;
+
+    public async Task<IReadOnlyList<DailyNoteEntity>> ListByDayAsync(DateOnly day, CancellationToken ct = default) =>
+        await _context.DailyNotes.AsNoTracking()
+            .Where(n => n.Date == day)
+            .OrderBy(n => n.SortOrder)
+            .ToListAsync(ct);
+
+    public async Task<IReadOnlyList<DailyNoteEntity>> ListBetweenAsync(
+        DateOnly start, DateOnly end, CancellationToken ct = default) =>
+        await _context.DailyNotes.AsNoTracking()
+            .Where(n => n.Date >= start && n.Date <= end)
+            .OrderBy(n => n.Date).ThenBy(n => n.SortOrder)
+            .ToListAsync(ct);
+
+    public async Task<DailyNoteEntity> AddAsync(DateOnly day, string text, CancellationToken ct = default)
+    {
+        var nextOrder = await _context.DailyNotes
+            .Where(n => n.Date == day)
+            .Select(n => (int?)n.SortOrder)
+            .MaxAsync(ct) ?? -1;
+
+        var note = new DailyNoteEntity
+        {
+            Date = day,
+            Text = text,
+            SortOrder = nextOrder + 1,
+            CreatedAt = DateTime.UtcNow,
+        };
+        _context.DailyNotes.Add(note);
+        await _context.SaveChangesAsync(ct);
+        return note;
+    }
+
+    public async Task UpdateAsync(string id, string text, CancellationToken ct = default)
+    {
+        var row = await _context.DailyNotes.FirstOrDefaultAsync(n => n.Id == id, ct);
+        if (row is null) return;
+        row.Text = text;
+        await _context.SaveChangesAsync(ct);
+    }
+
+    public async Task DeleteAsync(string id, CancellationToken ct = default)
+    {
+        var row = await _context.DailyNotes.FirstOrDefaultAsync(n => n.Id == id, ct);
+        if (row is null) return;
+        _context.DailyNotes.Remove(row);
+        await _context.SaveChangesAsync(ct);
+    }
+}
diff --git a/tests/ClaudeDo.Worker.Tests/Repositories/DailyNoteRepositoryTests.cs b/tests/ClaudeDo.Worker.Tests/Repositories/DailyNoteRepositoryTests.cs
new file mode 100644
index 0000000..a067a31
--- /dev/null
+++ b/tests/ClaudeDo.Worker.Tests/Repositories/DailyNoteRepositoryTests.cs
@@ -0,0 +1,67 @@
+using ClaudeDo.Data.Models;
+using ClaudeDo.Data.Repositories;
+using ClaudeDo.Worker.Tests.Infrastructure;
+
+namespace ClaudeDo.Worker.Tests.Repositories;
+
+public class DailyNoteRepositoryTests : IDisposable
+{
+    private readonly DbFixture _db = new();
+    public void Dispose() => _db.Dispose();
+
+    [Fact]
+    public async Task Add_AssignsIncrementingSortOrder_WithinDay()
+    {
+        var day = new DateOnly(2026, 6, 1);
+        using (var ctx = _db.CreateContext())
+        {
+            var repo = new DailyNoteRepository(ctx);
+            await repo.AddAsync(day, "first");
+            await repo.AddAsync(day, "second");
+        }
+        using var read = _db.CreateContext();
+        var notes = await new DailyNoteRepository(read).ListByDayAsync(day);
+        Assert.Equal(new[] { "first", "second" }, notes.Select(n => n.Text));
+        Assert.Equal(new[] { 0, 1 }, notes.Select(n => n.SortOrder));
+    }
+
+    [Fact]
+    public async Task ListBetween_ReturnsOnlyInRange_OrderedByDateThenSort()
+    {
+        using (var ctx = _db.CreateContext())
+        {
+            var repo = new DailyNoteRepository(ctx);
+            await repo.AddAsync(new DateOnly(2026, 5, 31), "before");
+            await repo.AddAsync(new DateOnly(2026, 6, 1), "in-a");
+            await repo.AddAsync(new DateOnly(2026, 6, 2), "in-b");
+            await repo.AddAsync(new DateOnly(2026, 6, 5), "after");
+        }
+        using var read = _db.CreateContext();
+        var notes = await new DailyNoteRepository(read)
+            .ListBetweenAsync(new DateOnly(2026, 6, 1), new DateOnly(2026, 6, 2));
+        Assert.Equal(new[] { "in-a", "in-b" }, notes.Select(n => n.Text));
+    }
+
+    [Fact]
+    public async Task Update_And_Delete_Work()
+    {
+        var day = new DateOnly(2026, 6, 1);
+        string id;
+        using (var ctx = _db.CreateContext())
+        {
+            var n = await new DailyNoteRepository(ctx).AddAsync(day, "orig");
+            id = n.Id;
+        }
+        using (var ctx = _db.CreateContext())
+            await new DailyNoteRepository(ctx).UpdateAsync(id, "edited");
+        using (var ctx = _db.CreateContext())
+        {
+            var notes = await new DailyNoteRepository(ctx).ListByDayAsync(day);
+            Assert.Equal("edited", notes.Single().Text);
+        }
+        using (var ctx = _db.CreateContext())
+            await new DailyNoteRepository(ctx).DeleteAsync(id);
+        using var read = _db.CreateContext();
+        Assert.Empty(await new DailyNoteRepository(read).ListByDayAsync(day));
+    }
+}