diff --git a/internal/runner/runner.go b/internal/runner/runner.go
index ef5f57c..c0e3dfc 100644
--- a/internal/runner/runner.go
+++ b/internal/runner/runner.go
@@ -23,10 +23,15 @@ import (
 )
 
 // VideoStore is the durable persistence the run loop needs: assign a stable id +
-// metadata, and read the already-summarized set. *store.Store satisfies it.
+// metadata, read the already-summarized set, and (for manual summarization mode)
+// read the user's mode + queued videos and clear a video's queue flag once it has
+// been summarized. *store.Store satisfies it.
 type VideoStore interface {
 	UpsertVideo(ctx context.Context, v domain.Video) (string, error)
 	SeenVideoIDs(ctx context.Context, userID string) (map[string]bool, error)
+	GetAutoSummarize(ctx context.Context, userID string) (bool, error)
+	RequestedVideoIDs(ctx context.Context, userID string) (map[string]bool, error)
+	ClearSummarizeRequested(ctx context.Context, userID, videoID string) error
 }
 
 // Processor runs the core use case for a single video. *usecase.Engine
@@ -59,6 +64,7 @@ type Stats struct {
 	Summarized    int
 	SkippedSeen   int
 	SkippedNoText int
+	SkippedManual int // discovered but not queued, in manual mode
 	Errors        int
 }
 
@@ -82,6 +88,22 @@ func (r *Runner) RunOnce(ctx context.Context) (Stats, error) {
 		return stats, fmt.Errorf("runner: load seen videos: %w", err)
 	}
 
+	// Summarization mode (per-user, ADR-012). Auto = summarize every unseen video
+	// (the original behavior). Manual = still discover/persist videos so the user
+	// sees them, but only summarize the ones explicitly queued via the web UI
+	// (summarize_requested). The queued set is loaded once per pass, like seen.
+	auto, err := r.store.GetAutoSummarize(ctx, r.userID)
+	if err != nil {
+		return stats, fmt.Errorf("runner: load summarize mode: %w", err)
+	}
+	var requested map[string]bool
+	if !auto {
+		requested, err = r.store.RequestedVideoIDs(ctx, r.userID)
+		if err != nil {
+			return stats, fmt.Errorf("runner: load requested videos: %w", err)
+		}
+	}
+
 	subs, err := r.src.ListSubscriptions(ctx, r.userID)
 	if err != nil {
 		return stats, fmt.Errorf("runner: list subscriptions: %w", err)
@@ -112,6 +134,14 @@ func (r *Runner) RunOnce(ctx context.Context) (Stats, error) {
 			}
 			seen[id] = true // also guard against the same video within this pass
 
+			// Manual mode: skip summarization for videos the user has not queued.
+			// Discovery already happened (UpsertVideo above), so the new video is
+			// visible in the list; it just isn't summarized until requested.
+			if !auto && !requested[id] {
+				stats.SkippedManual++
+				continue
+			}
+
 			if fetchDelay > 0 {
 				time.Sleep(fetchDelay)
 			}
@@ -127,6 +157,15 @@ func (r *Runner) RunOnce(ctx context.Context) (Stats, error) {
 				r.log.Info("skipped video (no transcript)", "video", v.ProviderVideoID, "title", v.Title)
 			case res.Summary != nil:
 				stats.Summarized++
+				// In manual mode the video was processed because it was queued;
+				// clear the flag so it is not re-summarized and the UI drops the
+				// "Queued" chip. (Auto mode never sets the flag.)
+				if !auto {
+					if err := r.store.ClearSummarizeRequested(ctx, r.userID, id); err != nil {
+						errs = append(errs, fmt.Errorf("clear summarize flag %q: %w", v.ProviderVideoID, err))
+						stats.Errors++
+					}
+				}
 				r.log.Info("summarized video", "video", v.ProviderVideoID, "title", v.Title,
 					"provider", res.Summary.AIProvider, "model", res.Summary.AIModel)
 			}
@@ -145,7 +184,7 @@ func (r *Runner) Loop(ctx context.Context, interval time.Duration) error {
 		r.log.Info("run pass complete",
 			"candidates", stats.Candidates, "summarized", stats.Summarized,
 			"skipped_seen", stats.SkippedSeen, "skipped_no_text", stats.SkippedNoText,
-			"errors", stats.Errors)
+			"skipped_manual", stats.SkippedManual, "errors", stats.Errors)
 		if err != nil {
 			r.log.Warn("run pass had errors", "err", err)
 		}
diff --git a/internal/runner/runner_test.go b/internal/runner/runner_test.go
index 5bacdce..eb08480 100644
--- a/internal/runner/runner_test.go
+++ b/internal/runner/runner_test.go
@@ -40,9 +40,14 @@ func (f *fakeSource) FetchTranscript(_ context.Context, v domain.Video) (domain.
 
 // fakeStore assigns deterministic ids ("id-"+provider video id) so a pre-seeded
 // seen set lines up with UpsertVideo output, modelling cross-restart dedup.
+// auto controls the summarization mode; requested is the manual-mode queue keyed
+// by store id; cleared records the ids whose queue flag the runner reset.
 type fakeStore struct {
-	seen     map[string]bool
-	upserted []domain.Video
+	seen      map[string]bool
+	upserted  []domain.Video
+	auto      bool
+	requested map[string]bool
+	cleared   []string
 }
 
 func (f *fakeStore) UpsertVideo(_ context.Context, v domain.Video) (string, error) {
@@ -58,6 +63,23 @@ func (f *fakeStore) SeenVideoIDs(_ context.Context, _ string) (map[string]bool,
 	return cp, nil
 }
 
+func (f *fakeStore) GetAutoSummarize(_ context.Context, _ string) (bool, error) {
+	return f.auto, nil
+}
+
+func (f *fakeStore) RequestedVideoIDs(_ context.Context, _ string) (map[string]bool, error) {
+	cp := make(map[string]bool, len(f.requested))
+	for k, v := range f.requested {
+		cp[k] = v
+	}
+	return cp, nil
+}
+
+func (f *fakeStore) ClearSummarizeRequested(_ context.Context, _, videoID string) error {
+	f.cleared = append(f.cleared, videoID)
+	return nil
+}
+
 type fakeSummarizer struct{}
 
 func (fakeSummarizer) Summarize(_ context.Context, v domain.Video, _ domain.Transcript) (domain.Summary, error) {
@@ -91,7 +113,7 @@ func TestRunOnce_SummarizesNewVideos(t *testing.T) {
 		subs:   []domain.Subscription{sub("chan1", "Channel One")},
 		videos: map[string][]domain.Video{"chan1": {vid("v1", "Video 1"), vid("v2", "Video 2")}},
 	}
-	st := &fakeStore{seen: map[string]bool{}}
+	st := &fakeStore{seen: map[string]bool{}, auto: true}
 	sink := &recordingSink{}
 	eng := usecase.NewEngine(src, fakeSummarizer{}, sink)
 	r := runner.New(src, st, eng, testUser, quietLogger())
@@ -114,7 +136,7 @@ func TestRunOnce_SkipsAlreadySummarized(t *testing.T) {
 		videos: map[string][]domain.Video{"chan1": {vid("v1", "Video 1"), vid("v2", "Video 2")}},
 	}
 	// v1 was summarized in a prior run (durable seen set).
-	st := &fakeStore{seen: map[string]bool{"id-v1": true}}
+	st := &fakeStore{seen: map[string]bool{"id-v1": true}, auto: true}
 	sink := &recordingSink{}
 	eng := usecase.NewEngine(src, fakeSummarizer{}, sink)
 	r := runner.New(src, st, eng, testUser, quietLogger())
@@ -133,7 +155,7 @@ func TestRunOnce_SkipsVideosWithoutTranscript(t *testing.T) {
 		videos:      map[string][]domain.Video{"chan1": {vid("v1", "Video 1")}},
 		transcripts: map[string]domain.Transcript{"v1": {Source: domain.SourceNone}},
 	}
-	st := &fakeStore{seen: map[string]bool{}}
+	st := &fakeStore{seen: map[string]bool{}, auto: true}
 	sink := &recordingSink{}
 	eng := usecase.NewEngine(src, fakeSummarizer{}, sink)
 	r := runner.New(src, st, eng, testUser, quietLogger())
@@ -145,13 +167,53 @@ func TestRunOnce_SkipsVideosWithoutTranscript(t *testing.T) {
 	require.Empty(t, sink.delivered, "no summary delivered when there is no transcript")
 }
 
+func TestRunOnce_ManualMode_SkipsUnrequested(t *testing.T) {
+	src := &fakeSource{
+		subs:   []domain.Subscription{sub("chan1", "Channel One")},
+		videos: map[string][]domain.Video{"chan1": {vid("v1", "Video 1"), vid("v2", "Video 2")}},
+	}
+	// Manual mode, nothing queued: discover (upsert) but summarize nothing.
+	st := &fakeStore{seen: map[string]bool{}, auto: false, requested: map[string]bool{}}
+	sink := &recordingSink{}
+	eng := usecase.NewEngine(src, fakeSummarizer{}, sink)
+	r := runner.New(src, st, eng, testUser, quietLogger())
+
+	stats, err := r.RunOnce(context.Background())
+	require.NoError(t, err)
+	require.Equal(t, 2, stats.Candidates)
+	require.Equal(t, 2, stats.SkippedManual, "manual mode skips unqueued videos")
+	require.Equal(t, 0, stats.Summarized)
+	require.Empty(t, sink.delivered, "no summary in manual mode without a request")
+	require.Len(t, st.upserted, 2, "discovery still persists every candidate")
+}
+
+func TestRunOnce_ManualMode_ProcessesRequested(t *testing.T) {
+	src := &fakeSource{
+		subs:   []domain.Subscription{sub("chan1", "Channel One")},
+		videos: map[string][]domain.Video{"chan1": {vid("v1", "Video 1"), vid("v2", "Video 2")}},
+	}
+	// Manual mode, v1 queued (by store id). Only v1 is summarized; its flag clears.
+	st := &fakeStore{seen: map[string]bool{}, auto: false, requested: map[string]bool{"id-v1": true}}
+	sink := &recordingSink{}
+	eng := usecase.NewEngine(src, fakeSummarizer{}, sink)
+	r := runner.New(src, st, eng, testUser, quietLogger())
+
+	stats, err := r.RunOnce(context.Background())
+	require.NoError(t, err)
+	require.Equal(t, 1, stats.Summarized, "only the queued video is summarized")
+	require.Equal(t, 1, stats.SkippedManual, "the unqueued video is skipped")
+	require.Len(t, sink.delivered, 1)
+	require.Equal(t, "id-v1", sink.delivered[0].VideoID)
+	require.Equal(t, []string{"id-v1"}, st.cleared, "the queue flag is cleared after summarizing")
+}
+
 func TestRunOnce_UpsertsEveryCandidate(t *testing.T) {
 	src := &fakeSource{
 		subs:   []domain.Subscription{sub("chan1", "Channel One")},
 		videos: map[string][]domain.Video{"chan1": {vid("v1", "Video 1"), vid("v2", "Video 2")}},
 	}
 	// Even an already-seen video gets upserted so its metadata stays fresh.
-	st := &fakeStore{seen: map[string]bool{"id-v1": true}}
+	st := &fakeStore{seen: map[string]bool{"id-v1": true}, auto: true}
 	eng := usecase.NewEngine(src, fakeSummarizer{}, &recordingSink{})
 	r := runner.New(src, st, eng, testUser, quietLogger())