Great question. In Prefect 3.x, the Flow Run Graph is a data lineage view, not a full dependency graph. - A line is drawn only when a downstream task uses the upstream task’s output (i.e., the upstream task’s result is passed as an input to the downstream task). - No line is drawn for “logical” dependencies that don’t pass data, such as: - Using

depends_on

-style ordering - Awaiting a task just to ensure it finishes, but not using its result - Concurrency/group limits or other orchestration constraints Subflows are a special case: the graph can show an “encapsulating” relationship from a parent task to the subflow run, but typical edges between tasks still require data flow. Quick example:

from prefect import flow, task

@task
def A():
    return 1

@task
def B(x):
    return x + 1

@task
def C():
    return "done"

@flow
def my_flow():
    a = A()
    B(a)     # Line A → B (B uses A’s output)
    C()      # No line from A → C (no data passed)

Notes: - The graph only includes tasks that actually started (non-pending). If something hasn’t started, you may not see it or its edges yet. - If you want a relationship to appear as a line, pass the upstream result (or a value derived from it) into the downstream task.