1 files changed, 30 insertions, 0 deletions
diff --git a/internal/storage/db.go b/internal/storage/db.go
index a16ad4e..d571c2e 100644
--- a/internal/storage/db.go
+++ b/internal/storage/db.go
@@ -287,6 +287,36 @@ func (s *DB) ListSubtasks(parentID string) ([]*task.Task, error) {
 	return tasks, rows.Err()
 }
 
+// ListDependents returns tasks that directly depend on taskID — i.e. those
+// whose depends_on_json contains taskID. depends_on_json has no reverse
+// index, so this is a full-table scan; the codebase already accepts this
+// tradeoff for other JSON-blob columns at self-hosted scale (see the
+// "Additive migration strategy is fragile" design-debt note in CLAUDE.md).
+// Only direct dependents are returned — callers that need the full
+// transitive downstream subtree (e.g. cascade-cancellation) must recurse.
+func (s *DB) ListDependents(taskID string) ([]*task.Task, error) {
+	rows, err := s.db.Query(`SELECT id, name, description, elaboration_input, project, repository_url, config_json, priority, timeout_ns, retry_json, tags_json, depends_on_json, parent_task_id, state, created_at, updated_at, rejection_comment, question_json, summary, interactions_json FROM tasks`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var dependents []*task.Task
+	for rows.Next() {
+		t, err := scanTaskRows(rows)
+		if err != nil {
+			return nil, err
+		}
+		for _, depID := range t.DependsOn {
+			if depID == taskID {
+				dependents = append(dependents, t)
+				break
+			}
+		}
+	}
+	return dependents, rows.Err()
+}
+
 // UpdateTaskState atomically updates a task's state, enforcing valid
 // transitions. The transition is attributed to the system actor; callers
 // acting on behalf of a user should use UpdateTaskStateBy.