feat: show agent turn summary in agents sidebar (#24942)

Persists the agent-generated turn-end summary on `chats` and shows it as
the Agents sidebar subtitle when present, falling back to the model
name. Errors still take precedence.

> Mux is acting on Mike's behalf.

## What changes

**Storage.** New nullable `last_turn_summary` column on `chats`
(migration `000486`). New `UpdateChatLastTurnSummary` query normalizes
blank/whitespace input to `NULL`, preserves `updated_at` (so the chat
does not jump to the top of the sidebar on summary writes), and uses an
`expected_updated_at` stale-write guard so an older async summary cannot
overwrite a newer turn.

**Backend.** `coderd/x/chatd/chatd.go` decouples summary generation from
webpush. Generated summaries persist for completed parent turns even
when webpush is unconfigured or has no subscriptions. The same generated
text is reused as the webpush body when webpush is configured, so the
summary model is not called twice. Generic fallback push text is no
longer persisted; it clears any stale summary instead.
Error/interrupt/pending-action terminal paths clear `last_turn_summary`
for the latest turn.

**Frontend.** `AgentsSidebar.tsx` subtitle priority is now `errorReason
|| lastTurnSummary || modelName`, normalized via the existing
`asNonEmptyString` helper from `blockUtils.ts`.

## Tests

- `TestUpdateChatLastTurnSummary` (database): success,
whitespace-to-NULL, stale guard rejects, `updated_at` preserved.
- `TestUpdateLastTurnSummaryRejectsStaleWrites` (chatd internal): direct
stale-`expected_updated_at` test.
- `TestSuccessfulChatPersistsTurnSummaryWithoutWebPush`: persistence
works without webpush subscriptions.
- `TestSuccessfulChatSendsWebPushWithSummary`: same generated text
drives both DB and push body.
-
`TestSuccessfulChatSendsWebPushFallbackWithoutSummaryForEmptyAssistantText`:
fallback text is not persisted.
- `TestErroredChatClearsLastTurnSummaryAndSendsWebPush`: error path
clears the field.
- `TestInterruptChatDoesNotSendWebPushNotification`: interrupt path
clears the field, no push fires.
- `AgentsSidebar.test.tsx`: subtitle priority for summary-present,
error-wins, no-summary fallback, whitespace fallback.
- `AgentsSidebar.stories.tsx`: `ChatWithTurnSummary` and
`ChatWithTurnSummaryAndError`.

## Notes

- No backfill. Existing chats keep showing the model name until their
next turn completes.
- Parent chats only in this iteration; the field is rendered on any
`Chat` if a future change extends generation to children.
- Decoupling generation from webpush adds quickgen model calls for
completed parent turns that previously skipped generation when no
subscriptions existed. Existing parent-only, assistant-text-present,
`PushSummaryModel` configured, and bounded-timeout gates keep this
behavior bounded.

coderd/database/db2sdk/db2sdk.go

@@ -1667,6 +1667,9 @@ func Chat(c database.Chat, diffStatus *database.ChatDiffStatus, files []database
 		ClientType:        codersdk.ChatClientType(c.ClientType),
 		LastError:         lastError,
 	}
+	if c.LastTurnSummary.Valid {
+		chat.LastTurnSummary = &c.LastTurnSummary.String
+	}
 	if c.PlanMode.Valid {
 		chat.PlanMode = codersdk.ChatPlanMode(c.PlanMode.ChatPlanMode)
 	}

coderd/database/db2sdk/db2sdk_test.go

@@ -941,6 +941,7 @@ func TestChat_AllFieldsPopulated(t *testing.T) {
 		Status:            database.ChatStatusRunning,
 		ClientType:        database.ChatClientTypeUi,
 		LastError:         pqtype.NullRawMessage{RawMessage: lastErrorRaw, Valid: true},
+		LastTurnSummary:   sql.NullString{String: "turn completed", Valid: true},
 		CreatedAt:         now,
 		UpdatedAt:         now,
 		Archived:          true,

coderd/database/dbauthz/dbauthz.go

@@ -6308,6 +6308,17 @@ func (q *querier) UpdateChatLastReadMessageID(ctx context.Context, arg database.
 	return q.db.UpdateChatLastReadMessageID(ctx, arg)
 }
 
+func (q *querier) UpdateChatLastTurnSummary(ctx context.Context, arg database.UpdateChatLastTurnSummaryParams) (int64, error) {
+	chat, err := q.db.GetChatByID(ctx, arg.ID)
+	if err != nil {
+		return 0, err
+	}
+	if err := q.authorizeContext(ctx, policy.ActionUpdate, chat); err != nil {
+		return 0, err
+	}
+	return q.db.UpdateChatLastTurnSummary(ctx, arg)
+}
+
 func (q *querier) UpdateChatMCPServerIDs(ctx context.Context, arg database.UpdateChatMCPServerIDsParams) (database.Chat, error) {
 	chat, err := q.db.GetChatByID(ctx, arg.ID)
 	if err != nil {

coderd/database/dbauthz/dbauthz_test.go

@@ -1532,6 +1532,17 @@ func (s *MethodTestSuite) TestChats() {
 		dbm.EXPECT().UpdateChatLastInjectedContext(gomock.Any(), arg).Return(chat, nil).AnyTimes()
 		check.Args(arg).Asserts(chat, policy.ActionUpdate).Returns(chat)
 	}))
+	s.Run("UpdateChatLastTurnSummary", s.Mocked(func(dbm *dbmock.MockStore, faker *gofakeit.Faker, check *expects) {
+		chat := testutil.Fake(s.T(), faker, database.Chat{})
+		arg := database.UpdateChatLastTurnSummaryParams{
+			ID:                chat.ID,
+			ExpectedUpdatedAt: chat.UpdatedAt,
+			LastTurnSummary:   sql.NullString{String: "resolved the issue", Valid: true},
+		}
+		dbm.EXPECT().GetChatByID(gomock.Any(), chat.ID).Return(chat, nil).AnyTimes()
+		dbm.EXPECT().UpdateChatLastTurnSummary(gomock.Any(), arg).Return(int64(1), nil).AnyTimes()
+		check.Args(arg).Asserts(chat, policy.ActionUpdate).Returns(int64(1))
+	}))
 	s.Run("UpdateChatLastReadMessageID", s.Mocked(func(dbm *dbmock.MockStore, faker *gofakeit.Faker, check *expects) {
 		chat := testutil.Fake(s.T(), faker, database.Chat{})
 		arg := database.UpdateChatLastReadMessageIDParams{

coderd/database/dbmetrics/querymetrics.go

@@ -4544,6 +4544,14 @@ func (m queryMetricsStore) UpdateChatLastReadMessageID(ctx context.Context, arg
 	return r0
 }
 
+func (m queryMetricsStore) UpdateChatLastTurnSummary(ctx context.Context, arg database.UpdateChatLastTurnSummaryParams) (int64, error) {
+	start := time.Now()
+	r0, r1 := m.s.UpdateChatLastTurnSummary(ctx, arg)
+	m.queryLatencies.WithLabelValues("UpdateChatLastTurnSummary").Observe(time.Since(start).Seconds())
+	m.queryCounts.WithLabelValues(httpmw.ExtractHTTPRoute(ctx), httpmw.ExtractHTTPMethod(ctx), "UpdateChatLastTurnSummary").Inc()
+	return r0, r1
+}
+
 func (m queryMetricsStore) UpdateChatMCPServerIDs(ctx context.Context, arg database.UpdateChatMCPServerIDsParams) (database.Chat, error) {
 	start := time.Now()
 	r0, r1 := m.s.UpdateChatMCPServerIDs(ctx, arg)

coderd/database/dbmock/dbmock.go

@@ -8596,6 +8596,21 @@ func (mr *MockStoreMockRecorder) UpdateChatLastReadMessageID(ctx, arg any) *gomo
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "UpdateChatLastReadMessageID", reflect.TypeOf((*MockStore)(nil).UpdateChatLastReadMessageID), ctx, arg)
 }
 
+// UpdateChatLastTurnSummary mocks base method.
+func (m *MockStore) UpdateChatLastTurnSummary(ctx context.Context, arg database.UpdateChatLastTurnSummaryParams) (int64, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "UpdateChatLastTurnSummary", ctx, arg)
+	ret0, _ := ret[0].(int64)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// UpdateChatLastTurnSummary indicates an expected call of UpdateChatLastTurnSummary.
+func (mr *MockStoreMockRecorder) UpdateChatLastTurnSummary(ctx, arg any) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "UpdateChatLastTurnSummary", reflect.TypeOf((*MockStore)(nil).UpdateChatLastTurnSummary), ctx, arg)
+}
+
 // UpdateChatMCPServerIDs mocks base method.
 func (m *MockStore) UpdateChatMCPServerIDs(ctx context.Context, arg database.UpdateChatMCPServerIDsParams) (database.Chat, error) {
 	m.ctrl.T.Helper()

coderd/database/dump.sql

@@ -1451,6 +1451,7 @@ CREATE TABLE chats (
     organization_id uuid NOT NULL,
     plan_mode chat_plan_mode,
     client_type chat_client_type DEFAULT 'api'::chat_client_type NOT NULL,
+    last_turn_summary text,
     CONSTRAINT chats_pin_order_archived_check CHECK (((pin_order = 0) OR (archived = false))),
     CONSTRAINT chats_pin_order_parent_check CHECK (((pin_order = 0) OR (parent_chat_id IS NULL)))
 );

coderd/database/migrations/000488_chat_last_turn_summary.down.sql

@@ -0,0 +1 @@
+ALTER TABLE chats DROP COLUMN last_turn_summary;

coderd/database/migrations/000488_chat_last_turn_summary.up.sql

@@ -0,0 +1 @@
+ALTER TABLE chats ADD COLUMN last_turn_summary TEXT;

coderd/database/modelqueries.go

@@ -802,6 +802,7 @@ func (q *sqlQuerier) GetAuthorizedChats(ctx context.Context, arg GetChatsParams,
 			&i.Chat.OrganizationID,
 			&i.Chat.PlanMode,
 			&i.Chat.ClientType,
+			&i.Chat.LastTurnSummary,
 			&i.HasUnread); err != nil {
 			return nil, err
 		}

coderd/database/models.go

@@ -4380,6 +4380,7 @@ type Chat struct {
 	OrganizationID      uuid.UUID             `db:"organization_id" json:"organization_id"`
 	PlanMode            NullChatPlanMode      `db:"plan_mode" json:"plan_mode"`
 	ClientType          ChatClientType        `db:"client_type" json:"client_type"`
+	LastTurnSummary     sql.NullString        `db:"last_turn_summary" json:"last_turn_summary"`
 }
 
 type ChatDebugRun struct {

coderd/database/querier.go

@@ -1114,6 +1114,16 @@ type sqlcQuerier interface {
 	// Updates the last read message ID for a chat. This is used to track
 	// which messages the owner has seen, enabling unread indicators.
 	UpdateChatLastReadMessageID(ctx context.Context, arg UpdateChatLastReadMessageIDParams) error
+	// Updates the cached last completed turn summary for sidebar display.
+	// Empty or whitespace-only summaries are stored as NULL here so direct
+	// query callers cannot accidentally persist blank sidebar text.
+	// This intentionally preserves updated_at. The staleness guard relies on
+	// every new-turn query, such as UpdateChatStatus and AcquireChats, bumping
+	// updated_at. Future chat-field updates that do not bump updated_at can let
+	// stale summaries persist. If this query ever bumps updated_at, later
+	// goroutine summary writes will be rejected as stale.
+	// Two summary workers using the same freshness marker are last-write-wins.
+	UpdateChatLastTurnSummary(ctx context.Context, arg UpdateChatLastTurnSummaryParams) (int64, error)
 	UpdateChatMCPServerIDs(ctx context.Context, arg UpdateChatMCPServerIDsParams) (Chat, error)
 	UpdateChatMessageByID(ctx context.Context, arg UpdateChatMessageByIDParams) (ChatMessage, error)
 	UpdateChatModelConfig(ctx context.Context, arg UpdateChatModelConfigParams) (ChatModelConfig, error)

coderd/database/querier_test.go

@@ -11448,6 +11448,111 @@ func TestChatLabels(t *testing.T) {
 	})
 }
 
+func TestUpdateChatLastTurnSummary(t *testing.T) {
+	t.Parallel()
+	if testing.Short() {
+		t.SkipNow()
+	}
+
+	sqlDB := testSQLDB(t)
+	err := migrations.Up(sqlDB)
+	require.NoError(t, err)
+	db := database.New(sqlDB)
+
+	ctx := testutil.Context(t, testutil.WaitMedium)
+	owner := dbgen.User(t, db, database.User{})
+	org := dbgen.Organization(t, db, database.Organization{})
+	dbgen.OrganizationMember(t, db, database.OrganizationMember{UserID: owner.ID, OrganizationID: org.ID})
+
+	_, err = db.InsertChatProvider(ctx, database.InsertChatProviderParams{
+		Provider:             "openai",
+		DisplayName:          "OpenAI",
+		APIKey:               "test-key",
+		Enabled:              true,
+		CentralApiKeyEnabled: true,
+	})
+	require.NoError(t, err)
+
+	modelCfg, err := db.InsertChatModelConfig(ctx, database.InsertChatModelConfigParams{
+		Provider:             "openai",
+		Model:                "test-model",
+		DisplayName:          "Test Model",
+		CreatedBy:            uuid.NullUUID{UUID: owner.ID, Valid: true},
+		UpdatedBy:            uuid.NullUUID{UUID: owner.ID, Valid: true},
+		Enabled:              true,
+		IsDefault:            true,
+		ContextLimit:         128000,
+		CompressionThreshold: 80,
+		Options:              json.RawMessage(`{}`),
+	})
+	require.NoError(t, err)
+
+	chat, err := db.InsertChat(ctx, database.InsertChatParams{
+		OrganizationID:    org.ID,
+		Status:            database.ChatStatusWaiting,
+		ClientType:        database.ChatClientTypeUi,
+		OwnerID:           owner.ID,
+		LastModelConfigID: modelCfg.ID,
+		Title:             "summary-chat",
+	})
+	require.NoError(t, err)
+
+	affected, err := db.UpdateChatLastTurnSummary(ctx, database.UpdateChatLastTurnSummaryParams{
+		ID:                chat.ID,
+		ExpectedUpdatedAt: chat.UpdatedAt,
+		LastTurnSummary:   sql.NullString{String: "resolved the issue", Valid: true},
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, 1, affected)
+
+	fetched, err := db.GetChatByID(ctx, chat.ID)
+	require.NoError(t, err)
+	require.Equal(t, sql.NullString{String: "resolved the issue", Valid: true}, fetched.LastTurnSummary)
+	require.Equal(t, chat.UpdatedAt, fetched.UpdatedAt)
+
+	affected, err = db.UpdateChatLastTurnSummary(ctx, database.UpdateChatLastTurnSummaryParams{
+		ID:                chat.ID,
+		ExpectedUpdatedAt: chat.UpdatedAt,
+		LastTurnSummary:   sql.NullString{String: " \n\t ", Valid: true},
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, 1, affected)
+
+	fetched, err = db.GetChatByID(ctx, chat.ID)
+	require.NoError(t, err)
+	require.False(t, fetched.LastTurnSummary.Valid)
+	require.Equal(t, chat.UpdatedAt, fetched.UpdatedAt)
+
+	affected, err = db.UpdateChatLastTurnSummary(ctx, database.UpdateChatLastTurnSummaryParams{
+		ID:                chat.ID,
+		ExpectedUpdatedAt: chat.UpdatedAt,
+		LastTurnSummary:   sql.NullString{String: "fresh summary", Valid: true},
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, 1, affected)
+
+	advancedUpdatedAt := chat.UpdatedAt.Add(time.Second)
+	_, err = db.UpdateChatStatusPreserveUpdatedAt(ctx, database.UpdateChatStatusPreserveUpdatedAtParams{
+		ID:        chat.ID,
+		Status:    database.ChatStatusRunning,
+		UpdatedAt: advancedUpdatedAt,
+	})
+	require.NoError(t, err)
+
+	affected, err = db.UpdateChatLastTurnSummary(ctx, database.UpdateChatLastTurnSummaryParams{
+		ID:                chat.ID,
+		ExpectedUpdatedAt: chat.UpdatedAt,
+		LastTurnSummary:   sql.NullString{String: "stale summary", Valid: true},
+	})
+	require.NoError(t, err)
+	require.Zero(t, affected)
+
+	fetched, err = db.GetChatByID(ctx, chat.ID)
+	require.NoError(t, err)
+	require.Equal(t, sql.NullString{String: "fresh summary", Valid: true}, fetched.LastTurnSummary)
+	require.Equal(t, advancedUpdatedAt, fetched.UpdatedAt)
+}
+
 func TestDeleteChatDebugDataAfterMessageIDIncludesTriggeredRuns(t *testing.T) {
 	t.Parallel()
 

coderd/database/queries.sql.go

@@ -5120,7 +5120,7 @@ WHERE
             $3::int
     )
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type AcquireChatsParams struct {
@@ -5168,6 +5168,7 @@ func (q *sqlQuerier) AcquireChats(ctx context.Context, arg AcquireChatsParams) (
 			&i.OrganizationID,
 			&i.PlanMode,
 			&i.ClientType,
+			&i.LastTurnSummary,
 		); err != nil {
 			return nil, err
 		}
@@ -5306,9 +5307,9 @@ WITH chats AS (
     UPDATE chats
     SET archived = true, pin_order = 0, updated_at = NOW()
     WHERE id = $1::uuid OR root_chat_id = $1::uuid
-    RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 )
-SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 FROM chats
 ORDER BY (id = $1::uuid) DESC, created_at ASC, id ASC
 `
@@ -5350,6 +5351,7 @@ func (q *sqlQuerier) ArchiveChatByID(ctx context.Context, id uuid.UUID) ([]Chat,
 			&i.OrganizationID,
 			&i.PlanMode,
 			&i.ClientType,
+			&i.LastTurnSummary,
 		); err != nil {
 			return nil, err
 		}
@@ -5399,10 +5401,10 @@ archived AS (
     FROM to_archive t
     WHERE (c.id = t.id OR c.root_chat_id = t.id) -- cascade to children
       AND c.archived = false
-    RETURNING c.id, c.owner_id, c.workspace_id, c.title, c.status, c.worker_id, c.started_at, c.heartbeat_at, c.created_at, c.updated_at, c.parent_chat_id, c.root_chat_id, c.last_model_config_id, c.archived, c.last_error, c.mode, c.mcp_server_ids, c.labels, c.build_id, c.agent_id, c.pin_order, c.last_read_message_id, c.last_injected_context, c.dynamic_tools, c.organization_id, c.plan_mode, c.client_type
+    RETURNING c.id, c.owner_id, c.workspace_id, c.title, c.status, c.worker_id, c.started_at, c.heartbeat_at, c.created_at, c.updated_at, c.parent_chat_id, c.root_chat_id, c.last_model_config_id, c.archived, c.last_error, c.mode, c.mcp_server_ids, c.labels, c.build_id, c.agent_id, c.pin_order, c.last_read_message_id, c.last_injected_context, c.dynamic_tools, c.organization_id, c.plan_mode, c.client_type, c.last_turn_summary
 )
 SELECT
-    a.id, a.owner_id, a.workspace_id, a.title, a.status, a.worker_id, a.started_at, a.heartbeat_at, a.created_at, a.updated_at, a.parent_chat_id, a.root_chat_id, a.last_model_config_id, a.archived, a.last_error, a.mode, a.mcp_server_ids, a.labels, a.build_id, a.agent_id, a.pin_order, a.last_read_message_id, a.last_injected_context, a.dynamic_tools, a.organization_id, a.plan_mode, a.client_type,
+    a.id, a.owner_id, a.workspace_id, a.title, a.status, a.worker_id, a.started_at, a.heartbeat_at, a.created_at, a.updated_at, a.parent_chat_id, a.root_chat_id, a.last_model_config_id, a.archived, a.last_error, a.mode, a.mcp_server_ids, a.labels, a.build_id, a.agent_id, a.pin_order, a.last_read_message_id, a.last_injected_context, a.dynamic_tools, a.organization_id, a.plan_mode, a.client_type, a.last_turn_summary,
     -- Children inherit their root's activity so last_activity_at is never null.
     COALESCE(
         t.last_activity_at,
@@ -5447,6 +5449,7 @@ type AutoArchiveInactiveChatsRow struct {
 	OrganizationID      uuid.UUID             `db:"organization_id" json:"organization_id"`
 	PlanMode            NullChatPlanMode      `db:"plan_mode" json:"plan_mode"`
 	ClientType          ChatClientType        `db:"client_type" json:"client_type"`
+	LastTurnSummary     sql.NullString        `db:"last_turn_summary" json:"last_turn_summary"`
 	LastActivityAt      time.Time             `db:"last_activity_at" json:"last_activity_at"`
 }
 
@@ -5492,6 +5495,7 @@ func (q *sqlQuerier) AutoArchiveInactiveChats(ctx context.Context, arg AutoArchi
 			&i.OrganizationID,
 			&i.PlanMode,
 			&i.ClientType,
+			&i.LastTurnSummary,
 			&i.LastActivityAt,
 		); err != nil {
 			return nil, err
@@ -5642,7 +5646,7 @@ func (q *sqlQuerier) DeleteOldChats(ctx context.Context, arg DeleteOldChatsParam
 }
 
 const getActiveChatsByAgentID = `-- name: GetActiveChatsByAgentID :many
-SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 FROM chats
 WHERE agent_id = $1::uuid
     AND archived = false
@@ -5690,6 +5694,7 @@ func (q *sqlQuerier) GetActiveChatsByAgentID(ctx context.Context, agentID uuid.U
 			&i.OrganizationID,
 			&i.PlanMode,
 			&i.ClientType,
+			&i.LastTurnSummary,
 		); err != nil {
 			return nil, err
 		}
@@ -5706,7 +5711,7 @@ func (q *sqlQuerier) GetActiveChatsByAgentID(ctx context.Context, agentID uuid.U
 
 const getChatByID = `-- name: GetChatByID :one
 SELECT
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 FROM
     chats
 WHERE
@@ -5744,12 +5749,13 @@ func (q *sqlQuerier) GetChatByID(ctx context.Context, id uuid.UUID) (Chat, error
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
 
 const getChatByIDForUpdate = `-- name: GetChatByIDForUpdate :one
-SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type FROM chats WHERE id = $1::uuid FOR UPDATE
+SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary FROM chats WHERE id = $1::uuid FOR UPDATE
 `
 
 func (q *sqlQuerier) GetChatByIDForUpdate(ctx context.Context, id uuid.UUID) (Chat, error) {
@@ -5783,6 +5789,7 @@ func (q *sqlQuerier) GetChatByIDForUpdate(ctx context.Context, id uuid.UUID) (Ch
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -6890,7 +6897,7 @@ func (q *sqlQuerier) GetChatUsageLimitUserOverride(ctx context.Context, userID u
 
 const getChats = `-- name: GetChats :many
 SELECT
-    chats.id, chats.owner_id, chats.workspace_id, chats.title, chats.status, chats.worker_id, chats.started_at, chats.heartbeat_at, chats.created_at, chats.updated_at, chats.parent_chat_id, chats.root_chat_id, chats.last_model_config_id, chats.archived, chats.last_error, chats.mode, chats.mcp_server_ids, chats.labels, chats.build_id, chats.agent_id, chats.pin_order, chats.last_read_message_id, chats.last_injected_context, chats.dynamic_tools, chats.organization_id, chats.plan_mode, chats.client_type,
+    chats.id, chats.owner_id, chats.workspace_id, chats.title, chats.status, chats.worker_id, chats.started_at, chats.heartbeat_at, chats.created_at, chats.updated_at, chats.parent_chat_id, chats.root_chat_id, chats.last_model_config_id, chats.archived, chats.last_error, chats.mode, chats.mcp_server_ids, chats.labels, chats.build_id, chats.agent_id, chats.pin_order, chats.last_read_message_id, chats.last_injected_context, chats.dynamic_tools, chats.organization_id, chats.plan_mode, chats.client_type, chats.last_turn_summary,
     EXISTS (
         SELECT 1 FROM chat_messages cm
         WHERE cm.chat_id = chats.id
@@ -7011,6 +7018,7 @@ func (q *sqlQuerier) GetChats(ctx context.Context, arg GetChatsParams) ([]GetCha
 			&i.Chat.OrganizationID,
 			&i.Chat.PlanMode,
 			&i.Chat.ClientType,
+			&i.Chat.LastTurnSummary,
 			&i.HasUnread,
 		); err != nil {
 			return nil, err
@@ -7027,7 +7035,7 @@ func (q *sqlQuerier) GetChats(ctx context.Context, arg GetChatsParams) ([]GetCha
 }
 
 const getChatsByWorkspaceIDs = `-- name: GetChatsByWorkspaceIDs :many
-SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 FROM chats
 WHERE archived = false
   AND workspace_id = ANY($1::uuid[])
@@ -7071,6 +7079,7 @@ func (q *sqlQuerier) GetChatsByWorkspaceIDs(ctx context.Context, ids []uuid.UUID
 			&i.OrganizationID,
 			&i.PlanMode,
 			&i.ClientType,
+			&i.LastTurnSummary,
 		); err != nil {
 			return nil, err
 		}
@@ -7155,7 +7164,7 @@ func (q *sqlQuerier) GetChatsUpdatedAfter(ctx context.Context, updatedAfter time
 
 const getChildChatsByParentIDs = `-- name: GetChildChatsByParentIDs :many
 SELECT
-    chats.id, chats.owner_id, chats.workspace_id, chats.title, chats.status, chats.worker_id, chats.started_at, chats.heartbeat_at, chats.created_at, chats.updated_at, chats.parent_chat_id, chats.root_chat_id, chats.last_model_config_id, chats.archived, chats.last_error, chats.mode, chats.mcp_server_ids, chats.labels, chats.build_id, chats.agent_id, chats.pin_order, chats.last_read_message_id, chats.last_injected_context, chats.dynamic_tools, chats.organization_id, chats.plan_mode, chats.client_type,
+    chats.id, chats.owner_id, chats.workspace_id, chats.title, chats.status, chats.worker_id, chats.started_at, chats.heartbeat_at, chats.created_at, chats.updated_at, chats.parent_chat_id, chats.root_chat_id, chats.last_model_config_id, chats.archived, chats.last_error, chats.mode, chats.mcp_server_ids, chats.labels, chats.build_id, chats.agent_id, chats.pin_order, chats.last_read_message_id, chats.last_injected_context, chats.dynamic_tools, chats.organization_id, chats.plan_mode, chats.client_type, chats.last_turn_summary,
     EXISTS (
         SELECT 1 FROM chat_messages cm
         WHERE cm.chat_id = chats.id
@@ -7227,6 +7236,7 @@ func (q *sqlQuerier) GetChildChatsByParentIDs(ctx context.Context, arg GetChildC
 			&i.Chat.OrganizationID,
 			&i.Chat.PlanMode,
 			&i.Chat.ClientType,
+			&i.Chat.LastTurnSummary,
 			&i.HasUnread,
 		); err != nil {
 			return nil, err
@@ -7293,7 +7303,7 @@ func (q *sqlQuerier) GetLastChatMessageByRole(ctx context.Context, arg GetLastCh
 
 const getStaleChats = `-- name: GetStaleChats :many
 SELECT
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 FROM
     chats
 WHERE
@@ -7344,6 +7354,7 @@ func (q *sqlQuerier) GetStaleChats(ctx context.Context, staleThreshold time.Time
 			&i.OrganizationID,
 			&i.PlanMode,
 			&i.ClientType,
+			&i.LastTurnSummary,
 		); err != nil {
 			return nil, err
 		}
@@ -7457,7 +7468,7 @@ INSERT INTO chats (
     $16::chat_client_type
 )
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type InsertChatParams struct {
@@ -7527,6 +7538,7 @@ func (q *sqlQuerier) InsertChat(ctx context.Context, arg InsertChatParams) (Chat
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8062,9 +8074,9 @@ WITH chats AS (
         archived = false,
         updated_at = NOW()
     WHERE id = $1::uuid OR root_chat_id = $1::uuid
-    RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 )
-SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+SELECT id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 FROM chats
 ORDER BY (id = $1::uuid) DESC, created_at ASC, id ASC
 `
@@ -8110,6 +8122,7 @@ func (q *sqlQuerier) UnarchiveChatByID(ctx context.Context, id uuid.UUID) ([]Cha
 			&i.OrganizationID,
 			&i.PlanMode,
 			&i.ClientType,
+			&i.LastTurnSummary,
 		); err != nil {
 			return nil, err
 		}
@@ -8190,7 +8203,7 @@ UPDATE chats SET
     updated_at = NOW()
 WHERE
     id = $3::uuid
-RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatBuildAgentBindingParams struct {
@@ -8230,6 +8243,7 @@ func (q *sqlQuerier) UpdateChatBuildAgentBinding(ctx context.Context, arg Update
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8243,7 +8257,7 @@ SET
 WHERE
     id = $2::uuid
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatByIDParams struct {
@@ -8282,6 +8296,7 @@ func (q *sqlQuerier) UpdateChatByID(ctx context.Context, arg UpdateChatByIDParam
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8340,7 +8355,7 @@ SET
 WHERE
     id = $2::uuid
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatLabelsByIDParams struct {
@@ -8379,6 +8394,7 @@ func (q *sqlQuerier) UpdateChatLabelsByID(ctx context.Context, arg UpdateChatLab
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8388,7 +8404,7 @@ UPDATE chats SET
     last_injected_context = $1::jsonb
 WHERE
     id = $2::uuid
-RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatLastInjectedContextParams struct {
@@ -8431,6 +8447,7 @@ func (q *sqlQuerier) UpdateChatLastInjectedContext(ctx context.Context, arg Upda
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8444,7 +8461,7 @@ SET
 WHERE
     id = $2::uuid
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatLastModelConfigByIDParams struct {
@@ -8483,6 +8500,7 @@ func (q *sqlQuerier) UpdateChatLastModelConfigByID(ctx context.Context, arg Upda
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8505,6 +8523,40 @@ func (q *sqlQuerier) UpdateChatLastReadMessageID(ctx context.Context, arg Update
 	return err
 }
 
+const updateChatLastTurnSummary = `-- name: UpdateChatLastTurnSummary :execrows
+UPDATE chats
+SET
+    last_turn_summary = NULLIF(REGEXP_REPLACE(
+        $1::text, '^[[:space:]]+|[[:space:]]+$', '', 'g'
+    ), '')
+WHERE
+    id = $2::uuid
+    AND updated_at = $3::timestamptz
+`
+
+type UpdateChatLastTurnSummaryParams struct {
+	LastTurnSummary   sql.NullString `db:"last_turn_summary" json:"last_turn_summary"`
+	ID                uuid.UUID      `db:"id" json:"id"`
+	ExpectedUpdatedAt time.Time      `db:"expected_updated_at" json:"expected_updated_at"`
+}
+
+// Updates the cached last completed turn summary for sidebar display.
+// Empty or whitespace-only summaries are stored as NULL here so direct
+// query callers cannot accidentally persist blank sidebar text.
+// This intentionally preserves updated_at. The staleness guard relies on
+// every new-turn query, such as UpdateChatStatus and AcquireChats, bumping
+// updated_at. Future chat-field updates that do not bump updated_at can let
+// stale summaries persist. If this query ever bumps updated_at, later
+// goroutine summary writes will be rejected as stale.
+// Two summary workers using the same freshness marker are last-write-wins.
+func (q *sqlQuerier) UpdateChatLastTurnSummary(ctx context.Context, arg UpdateChatLastTurnSummaryParams) (int64, error) {
+	result, err := q.db.ExecContext(ctx, updateChatLastTurnSummary, arg.LastTurnSummary, arg.ID, arg.ExpectedUpdatedAt)
+	if err != nil {
+		return 0, err
+	}
+	return result.RowsAffected()
+}
+
 const updateChatMCPServerIDs = `-- name: UpdateChatMCPServerIDs :one
 UPDATE
     chats
@@ -8514,7 +8566,7 @@ SET
 WHERE
     id = $2::uuid
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatMCPServerIDsParams struct {
@@ -8553,6 +8605,7 @@ func (q *sqlQuerier) UpdateChatMCPServerIDs(ctx context.Context, arg UpdateChatM
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8684,7 +8737,7 @@ SET
 WHERE
     id = $2::uuid
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatPlanModeByIDParams struct {
@@ -8723,6 +8776,7 @@ func (q *sqlQuerier) UpdateChatPlanModeByID(ctx context.Context, arg UpdateChatP
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8740,7 +8794,7 @@ SET
 WHERE
     id = $6::uuid
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatStatusParams struct {
@@ -8790,6 +8844,7 @@ func (q *sqlQuerier) UpdateChatStatus(ctx context.Context, arg UpdateChatStatusP
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8807,7 +8862,7 @@ SET
 WHERE
     id = $7::uuid
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatStatusPreserveUpdatedAtParams struct {
@@ -8859,6 +8914,7 @@ func (q *sqlQuerier) UpdateChatStatusPreserveUpdatedAt(ctx context.Context, arg
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8874,7 +8930,7 @@ SET
 WHERE
     id = $2::uuid
 RETURNING
-    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+    id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatTitleByIDParams struct {
@@ -8913,6 +8969,7 @@ func (q *sqlQuerier) UpdateChatTitleByID(ctx context.Context, arg UpdateChatTitl
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }
@@ -8924,7 +8981,7 @@ UPDATE chats SET
     agent_id = $3::uuid,
     updated_at = NOW()
 WHERE id = $4::uuid
-RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type
+RETURNING id, owner_id, workspace_id, title, status, worker_id, started_at, heartbeat_at, created_at, updated_at, parent_chat_id, root_chat_id, last_model_config_id, archived, last_error, mode, mcp_server_ids, labels, build_id, agent_id, pin_order, last_read_message_id, last_injected_context, dynamic_tools, organization_id, plan_mode, client_type, last_turn_summary
 `
 
 type UpdateChatWorkspaceBindingParams struct {
@@ -8970,6 +9027,7 @@ func (q *sqlQuerier) UpdateChatWorkspaceBinding(ctx context.Context, arg UpdateC
 		&i.OrganizationID,
 		&i.PlanMode,
 		&i.ClientType,
+		&i.LastTurnSummary,
 	)
 	return i, err
 }

coderd/database/queries/chats.sql

@@ -632,6 +632,25 @@ WHERE
     id = @id::uuid
 RETURNING *;
 
+-- name: UpdateChatLastTurnSummary :execrows
+-- Updates the cached last completed turn summary for sidebar display.
+-- Empty or whitespace-only summaries are stored as NULL here so direct
+-- query callers cannot accidentally persist blank sidebar text.
+-- This intentionally preserves updated_at. The staleness guard relies on
+-- every new-turn query, such as UpdateChatStatus and AcquireChats, bumping
+-- updated_at. Future chat-field updates that do not bump updated_at can let
+-- stale summaries persist. If this query ever bumps updated_at, later
+-- goroutine summary writes will be rejected as stale.
+-- Two summary workers using the same freshness marker are last-write-wins.
+UPDATE chats
+SET
+    last_turn_summary = NULLIF(REGEXP_REPLACE(
+        sqlc.narg('last_turn_summary')::text, '^[[:space:]]+|[[:space:]]+$', '', 'g'
+    ), '')
+WHERE
+    id = @id::uuid
+    AND updated_at = @expected_updated_at::timestamptz;
+
 -- name: UpdateChatMCPServerIDs :one
 UPDATE
     chats