diff --git a/src/ClaudeDo.Worker/Hub/WorkerHub.cs b/src/ClaudeDo.Worker/Hub/WorkerHub.cs
index f040fb8..13720df 100644
--- a/src/ClaudeDo.Worker/Hub/WorkerHub.cs
+++ b/src/ClaudeDo.Worker/Hub/WorkerHub.cs
@@ -6,6 +6,7 @@ using ClaudeDo.Data.Repositories;
 using ClaudeDo.Worker.Agents;
 using ClaudeDo.Worker.Config;
 using ClaudeDo.Worker.Lifecycle;
+using ClaudeDo.Worker.Logging;
 using ClaudeDo.Worker.Online;
 using ClaudeDo.Worker.Planning;
 using ClaudeDo.Worker.Prime;
@@ -113,6 +114,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
     private readonly WorkerConfig _cfg;
     private readonly OnlineInboxConfig _onlineInboxConfig;
     private readonly OnlineTokenStore _onlineTokenStore;
+    private readonly LogRingBuffer? _logBuffer;
 
     public WorkerHub(
         QueueService queue,
@@ -136,7 +138,8 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         IRefineRunner refineRunner,
         WorkerConfig cfg,
         OnlineInboxConfig onlineInboxConfig,
-        OnlineTokenStore onlineTokenStore)
+        OnlineTokenStore onlineTokenStore,
+        LogRingBuffer? logBuffer = null)
     {
         _queue = queue;
         _waker = waker;
@@ -160,8 +163,13 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         _cfg = cfg;
         _onlineInboxConfig = onlineInboxConfig;
         _onlineTokenStore = onlineTokenStore;
+        _logBuffer = logBuffer;
     }
 
+    /// <summary>Recent worker log records (last 30 min, all levels) for the Log Visualizer overlay.</summary>
+    public IReadOnlyList<WorkerLogRecord> GetRecentLogs() =>
+        _logBuffer?.Snapshot() ?? Array.Empty<WorkerLogRecord>();
+
     // Maps the two exceptions service methods throw into client-facing HubExceptions:
     // KeyNotFoundException -> notFoundMessage, InvalidOperationException -> its own message.
     private static async Task HubGuard(Func<Task> action, string notFoundMessage = "task not found")
diff --git a/src/ClaudeDo.Worker/Logging/BroadcastLogSink.cs b/src/ClaudeDo.Worker/Logging/BroadcastLogSink.cs
new file mode 100644
index 0000000..dcb46e3
--- /dev/null
+++ b/src/ClaudeDo.Worker/Logging/BroadcastLogSink.cs
@@ -0,0 +1,100 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using ClaudeDo.Data.Models;
+using Serilog.Core;
+using Serilog.Events;
+
+namespace ClaudeDo.Worker.Logging;
+
+/// <summary>
+/// Serilog sink that (a) buffers every event (all levels) into <see cref="LogRingBuffer"/>
+/// for the Log Visualizer overlay, and (b) broadcasts Warn/Error events to the UI footer
+/// via the attached delegate — deduped within a rate-limit window, with a loop guard so
+/// SignalR's own log output cannot feed back into another broadcast.
+/// </summary>
+public sealed class BroadcastLogSink : ILogEventSink
+{
+    private static readonly TimeSpan RateLimitWindow = TimeSpan.FromSeconds(120);
+
+    private readonly LogRingBuffer _buffer;
+    private readonly Func<DateTime> _utcNow;
+    private readonly Dictionary<string, DateTime> _lastBroadcast = new();
+    private readonly object _gate = new();
+    private Func<string, WorkerLogLevel, DateTime, Task>? _broadcast;
+
+    public BroadcastLogSink(LogRingBuffer buffer, Func<DateTime>? utcNow = null)
+    {
+        _buffer = buffer;
+        _utcNow = utcNow ?? (() => DateTime.UtcNow);
+    }
+
+    /// <summary>Wired post-build, once the SignalR hub context exists.</summary>
+    public void Attach(Func<string, WorkerLogLevel, DateTime, Task> broadcast) => _broadcast = broadcast;
+
+    public void Emit(LogEvent logEvent)
+    {
+        var level = Map(logEvent.Level);
+        var message = Render(logEvent);
+        var tsUtc = logEvent.Timestamp.UtcDateTime;
+
+        _buffer.Append(new WorkerLogRecord(message, level, tsUtc));
+
+        if (level is not (WorkerLogLevel.Warn or WorkerLogLevel.Error))
+            return;
+        if (IsPlumbing(logEvent))
+            return;
+
+        var broadcast = _broadcast;
+        if (broadcast is null)
+            return;
+
+        lock (_gate)
+        {
+            if (_lastBroadcast.TryGetValue(message, out var last) && _utcNow() - last < RateLimitWindow)
+                return;
+            _lastBroadcast[message] = _utcNow();
+            Prune();
+        }
+
+        // Fire-and-forget. A broadcast failure itself logs (re-entering this sink), so it
+        // must never throw out of Emit nor leave an unobserved faulted task.
+        try { _ = broadcast(message, level, tsUtc).ContinueWith(t => { _ = t.Exception; }, TaskScheduler.Default); }
+        catch { /* swallow — logging must not crash on a transport hiccup */ }
+    }
+
+    private static WorkerLogLevel Map(LogEventLevel level) => level switch
+    {
+        LogEventLevel.Warning => WorkerLogLevel.Warn,
+        LogEventLevel.Error or LogEventLevel.Fatal => WorkerLogLevel.Error,
+        _ => WorkerLogLevel.Info,
+    };
+
+    private static string Render(LogEvent e)
+    {
+        var msg = e.RenderMessage();
+        if (e.Exception is { } ex)
+        {
+            var first = ex.Message.Split('\n', 2)[0].Trim();
+            msg = $"{msg}: {ex.GetType().Name}: {first}";
+        }
+        return msg;
+    }
+
+    private static bool IsPlumbing(LogEvent e)
+    {
+        if (!e.Properties.TryGetValue("SourceContext", out var v) || v is not ScalarValue { Value: string sc })
+            return false;
+        return sc.StartsWith("Microsoft.AspNetCore.SignalR", StringComparison.Ordinal)
+            || sc.StartsWith("Microsoft.AspNetCore.Http.Connections", StringComparison.Ordinal);
+    }
+
+    private void Prune()
+    {
+        if (_lastBroadcast.Count <= 256) return;
+        var cutoff = _utcNow() - RateLimitWindow;
+        foreach (var key in _lastBroadcast.Where(kv => kv.Value < cutoff).Select(kv => kv.Key).ToList())
+            _lastBroadcast.Remove(key);
+    }
+}
diff --git a/src/ClaudeDo.Worker/Logging/LogRingBuffer.cs b/src/ClaudeDo.Worker/Logging/LogRingBuffer.cs
new file mode 100644
index 0000000..05e1a2a
--- /dev/null
+++ b/src/ClaudeDo.Worker/Logging/LogRingBuffer.cs
@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace ClaudeDo.Worker.Logging;
+
+/// <summary>
+/// Thread-safe, time-bounded ring of recent log records. On each append it evicts
+/// records older than <c>window</c> and trims to <c>cap</c>. Feeds the Log Visualizer
+/// overlay via <see cref="Snapshot"/> (oldest-first). The clock is injectable for tests.
+/// </summary>
+public sealed class LogRingBuffer
+{
+    private readonly TimeSpan _window;
+    private readonly int _cap;
+    private readonly Func<DateTime> _utcNow;
+    private readonly LinkedList<WorkerLogRecord> _items = new();
+    private readonly object _gate = new();
+
+    public LogRingBuffer(TimeSpan window, int cap = 5000, Func<DateTime>? utcNow = null)
+    {
+        _window = window;
+        _cap = cap;
+        _utcNow = utcNow ?? (() => DateTime.UtcNow);
+    }
+
+    public void Append(WorkerLogRecord record)
+    {
+        lock (_gate)
+        {
+            _items.AddLast(record);
+            var cutoff = _utcNow() - _window;
+            while (_items.First is { } first &&
+                   (first.Value.TimestampUtc < cutoff || _items.Count > _cap))
+                _items.RemoveFirst();
+        }
+    }
+
+    /// <summary>Records still inside the window, oldest-first.</summary>
+    public IReadOnlyList<WorkerLogRecord> Snapshot()
+    {
+        lock (_gate)
+        {
+            var cutoff = _utcNow() - _window;
+            return _items.Where(r => r.TimestampUtc >= cutoff).ToList();
+        }
+    }
+}
diff --git a/src/ClaudeDo.Worker/Logging/WorkerLogRecord.cs b/src/ClaudeDo.Worker/Logging/WorkerLogRecord.cs
new file mode 100644
index 0000000..dd724a8
--- /dev/null
+++ b/src/ClaudeDo.Worker/Logging/WorkerLogRecord.cs
@@ -0,0 +1,7 @@
+using System;
+using ClaudeDo.Data.Models;
+
+namespace ClaudeDo.Worker.Logging;
+
+/// <summary>One captured log line for the in-memory ring buffer / Log Visualizer overlay.</summary>
+public sealed record WorkerLogRecord(string Message, WorkerLogLevel Level, DateTime TimestampUtc);
diff --git a/src/ClaudeDo.Worker/Program.cs b/src/ClaudeDo.Worker/Program.cs
index 92450be..a5daaea 100644
--- a/src/ClaudeDo.Worker/Program.cs
+++ b/src/ClaudeDo.Worker/Program.cs
@@ -7,6 +7,7 @@ using ClaudeDo.Worker.Config;
 using ClaudeDo.Worker.External;
 using ClaudeDo.Worker.Hub;
 using ClaudeDo.Worker.Lifecycle;
+using ClaudeDo.Worker.Logging;
 using ClaudeDo.Worker.Planning;
 using ClaudeDo.Worker.Queue;
 using ClaudeDo.Worker.Runner;
@@ -34,13 +35,22 @@ var builder = WebApplication.CreateBuilder(args);
 
 var logRoot = cfg.LogRoot;
 Directory.CreateDirectory(logRoot);
+
+// In-memory ring + broadcast sink power the footer log strip and the Log Visualizer
+// overlay. Created pre-build so Serilog can write to the sink; the SignalR broadcaster
+// is attached once the host is built (see below).
+var logBuffer = new LogRingBuffer(TimeSpan.FromMinutes(30));
+var broadcastSink = new BroadcastLogSink(logBuffer);
+
 builder.Host.UseSerilog((ctx, lc) => lc
     .MinimumLevel.Information()
     .WriteTo.File(
         System.IO.Path.Combine(logRoot, "worker-.log"),
         rollingInterval: RollingInterval.Day,
         retainedFileCountLimit: 7,
-        shared: true));
+        shared: true)
+    .WriteTo.Sink(broadcastSink));
+builder.Services.AddSingleton(logBuffer);
 
 builder.Services.AddDbContextFactory<ClaudeDoDbContext>(opt =>
     opt.UseSqlite($"Data Source={cfg.DbPath}"));
@@ -180,6 +190,10 @@ builder.WebHost.UseUrls($"http://127.0.0.1:{cfg.SignalRPort}");
 
 var app = builder.Build();
 
+// Now that the hub context exists, let the broadcast sink push Warn/Error to the footer.
+var logBroadcaster = app.Services.GetRequiredService<HubBroadcaster>();
+broadcastSink.Attach((message, level, ts) => logBroadcaster.WorkerLog(message, level, ts));
+
 using (var scope = app.Services.CreateScope())
 {
     ClaudeDoDbContext.MigrateAndConfigure(
diff --git a/tests/ClaudeDo.Worker.Tests/Logging/BroadcastLogSinkTests.cs b/tests/ClaudeDo.Worker.Tests/Logging/BroadcastLogSinkTests.cs
new file mode 100644
index 0000000..2827486
--- /dev/null
+++ b/tests/ClaudeDo.Worker.Tests/Logging/BroadcastLogSinkTests.cs
@@ -0,0 +1,107 @@
+using ClaudeDo.Data.Models;
+using ClaudeDo.Worker.Logging;
+using Serilog.Events;
+using Serilog.Parsing;
+
+namespace ClaudeDo.Worker.Tests.Logging;
+
+public class BroadcastLogSinkTests
+{
+    private static readonly DateTimeOffset EvtTime = new(2026, 6, 23, 8, 0, 0, TimeSpan.Zero);
+    private static readonly MessageTemplateParser Parser = new();
+
+    private static LogEvent Evt(LogEventLevel level, string template, Exception? ex = null, string? sourceContext = null)
+    {
+        var props = new List<LogEventProperty>();
+        if (sourceContext is not null)
+            props.Add(new LogEventProperty("SourceContext", new ScalarValue(sourceContext)));
+        return new LogEvent(EvtTime, level, ex, Parser.Parse(template), props);
+    }
+
+    private static (BroadcastLogSink sink, LogRingBuffer buffer, List<(string msg, WorkerLogLevel lvl)> calls)
+        NewSink(Func<DateTime> clock)
+    {
+        var buffer = new LogRingBuffer(TimeSpan.FromHours(1), utcNow: () => new DateTime(2026, 6, 23, 8, 0, 0, DateTimeKind.Utc));
+        var sink = new BroadcastLogSink(buffer, clock);
+        var calls = new List<(string, WorkerLogLevel)>();
+        sink.Attach((m, l, _) => { calls.Add((m, l)); return Task.CompletedTask; });
+        return (sink, buffer, calls);
+    }
+
+    [Fact]
+    public void Buffers_all_levels()
+    {
+        var (sink, buffer, _) = NewSink(() => EvtTime.UtcDateTime);
+        sink.Emit(Evt(LogEventLevel.Information, "info"));
+        sink.Emit(Evt(LogEventLevel.Warning, "warn"));
+        sink.Emit(Evt(LogEventLevel.Error, "err"));
+
+        Assert.Equal(3, buffer.Snapshot().Count);
+    }
+
+    [Fact]
+    public void Broadcasts_only_warn_and_error()
+    {
+        var (sink, _, calls) = NewSink(() => EvtTime.UtcDateTime);
+        sink.Emit(Evt(LogEventLevel.Information, "info"));
+        sink.Emit(Evt(LogEventLevel.Warning, "warn"));
+        sink.Emit(Evt(LogEventLevel.Error, "err"));
+
+        Assert.Equal(new[] { WorkerLogLevel.Warn, WorkerLogLevel.Error }, calls.Select(c => c.lvl));
+    }
+
+    [Fact]
+    public void Dedupes_repeat_within_window_but_still_buffers()
+    {
+        var now = EvtTime.UtcDateTime;
+        var (sink, buffer, calls) = NewSink(() => now);
+        sink.Emit(Evt(LogEventLevel.Warning, "same"));
+        now = now.AddSeconds(30);
+        sink.Emit(Evt(LogEventLevel.Warning, "same"));
+
+        Assert.Single(calls);                 // second broadcast suppressed
+        Assert.Equal(2, buffer.Snapshot().Count); // both buffered
+    }
+
+    [Fact]
+    public void Allows_repeat_after_window()
+    {
+        var now = EvtTime.UtcDateTime;
+        var (sink, _, calls) = NewSink(() => now);
+        sink.Emit(Evt(LogEventLevel.Warning, "same"));
+        now = now.AddSeconds(121);
+        sink.Emit(Evt(LogEventLevel.Warning, "same"));
+
+        Assert.Equal(2, calls.Count);
+    }
+
+    [Fact]
+    public void Appends_exception_to_message()
+    {
+        var (sink, _, calls) = NewSink(() => EvtTime.UtcDateTime);
+        sink.Emit(Evt(LogEventLevel.Error, "boom", new InvalidOperationException("bad dir")));
+
+        Assert.Single(calls);
+        Assert.Equal("boom: InvalidOperationException: bad dir", calls[0].msg);
+    }
+
+    [Fact]
+    public void Plumbing_source_buffered_but_not_broadcast()
+    {
+        var (sink, buffer, calls) = NewSink(() => EvtTime.UtcDateTime);
+        sink.Emit(Evt(LogEventLevel.Error, "transport hiccup", sourceContext: "Microsoft.AspNetCore.SignalR.HubConnectionHandler"));
+
+        Assert.Empty(calls);
+        Assert.Single(buffer.Snapshot());
+    }
+
+    [Fact]
+    public void Does_not_throw_when_detached()
+    {
+        var buffer = new LogRingBuffer(TimeSpan.FromHours(1));
+        var sink = new BroadcastLogSink(buffer);
+        sink.Emit(Evt(LogEventLevel.Error, "no subscriber"));
+
+        Assert.Single(buffer.Snapshot());
+    }
+}
diff --git a/tests/ClaudeDo.Worker.Tests/Logging/LogRingBufferTests.cs b/tests/ClaudeDo.Worker.Tests/Logging/LogRingBufferTests.cs
new file mode 100644
index 0000000..bd35b3d
--- /dev/null
+++ b/tests/ClaudeDo.Worker.Tests/Logging/LogRingBufferTests.cs
@@ -0,0 +1,48 @@
+using ClaudeDo.Data.Models;
+using ClaudeDo.Worker.Logging;
+
+namespace ClaudeDo.Worker.Tests.Logging;
+
+public class LogRingBufferTests
+{
+    private static readonly DateTime Now = new(2026, 6, 23, 8, 0, 0, DateTimeKind.Utc);
+
+    private static WorkerLogRecord Rec(DateTime ts, string msg = "m", WorkerLogLevel lvl = WorkerLogLevel.Info)
+        => new(msg, lvl, ts);
+
+    [Fact]
+    public void Evicts_records_older_than_window_on_append()
+    {
+        var buf = new LogRingBuffer(TimeSpan.FromMinutes(30), utcNow: () => Now);
+        buf.Append(Rec(Now.AddMinutes(-40), "old"));
+        buf.Append(Rec(Now.AddMinutes(-10), "recent"));
+
+        var snap = buf.Snapshot();
+
+        Assert.Single(snap);
+        Assert.Equal("recent", snap[0].Message);
+    }
+
+    [Fact]
+    public void Evicts_oldest_beyond_cap()
+    {
+        var buf = new LogRingBuffer(TimeSpan.FromHours(1), cap: 3, utcNow: () => Now);
+        for (var i = 0; i < 5; i++) buf.Append(Rec(Now, $"m{i}"));
+
+        var snap = buf.Snapshot();
+
+        Assert.Equal(3, snap.Count);
+        Assert.Equal(new[] { "m2", "m3", "m4" }, snap.Select(r => r.Message));
+    }
+
+    [Fact]
+    public void Snapshot_is_oldest_first()
+    {
+        var buf = new LogRingBuffer(TimeSpan.FromHours(1), utcNow: () => Now);
+        buf.Append(Rec(Now.AddMinutes(-3), "a"));
+        buf.Append(Rec(Now.AddMinutes(-2), "b"));
+        buf.Append(Rec(Now.AddMinutes(-1), "c"));
+
+        Assert.Equal(new[] { "a", "b", "c" }, buf.Snapshot().Select(r => r.Message));
+    }
+}