Great question. By default, artifacts are attached to the run that creates them—so artifacts created in a subflow show up on the subflow’s run page. To have them appear on the parent (main) flow’s UI as well, you need to explicitly post an artifact to the parent flow run. Two common approaches: 1) Create the artifact in the parent after the subflow returns (simplest if you can pass the content back), or 2) From the subflow, create a second artifact that targets the parent’s

flow_run_id

. Here’s a pattern for option 2 using the Prefect client to target the parent run:

from prefect import flow
from prefect.artifacts import create_markdown_artifact
from prefect.runtime import flow_run
from prefect.client.orchestration import SyncPrefectClient
from prefect.client.schemas.actions import ArtifactCreate

@flow
def child():
    # Create an artifact for the child run (normal behavior)
    md = "# Child summary\nThis is the child artifact."
    create_markdown_artifact(md, key="child-summary")

    # Also attach the same artifact to the parent flow run
    parent_id = flow_run.parent_flow_run_id
    if parent_id:
        with SyncPrefectClient() as client:
            client.create_artifact(
                ArtifactCreate(
                    type="markdown",
                    key="child-summary",  # optional, helps de-duplicate/update
                    description="Child summary published to parent run",
                    data={"markdown": md},
                    flow_run_id=parent_id,  # <-- the key bit
                )
            )

@flow
def parent():
    child()

if __name__ == "__main__":
    parent()

Notes: - In a subflow,

prefect.runtime.flow_run.parent_flow_run_id

gives you the parent run ID; use that to target the parent. - If you want to attach to the top-level run in deeper nesting, use

prefect.runtime.flow_run.root_flow_run_id

. - The convenience functions like

create_markdown_artifact

attach to the current run; they don’t take a

flow_run_id

. Use the client if you need to target another run. - Use

key

to manage updates/deduplication of artifacts across re-runs. Docs: - Artifacts overview: Artifacts in Prefect 3.x - REST reference (create artifact): Create Artifact API