How to Remove Artifacts from a Running Flow

[ccoryellnf]

I have a long running flow that pulls data (slowly) from an API. I created an image artifact that displays status information for the running flow. Every 10% it moves forward to completion, a new artifact is created with the same key. However, all artifacts show-up. It would be nice to be able to remove all artifacts with a given key and add the new one in so I can always to to the flow and see the flow status graphs in the image artifact without having several of them there that ran previously.

[agammann]

You can keep the image artifact's ID and update that artifact, instead of creating another version for every percentage change:

import asyncio

from prefect import flow
from prefect.artifacts import acreate_image_artifact
from prefect.client.orchestration import get_client
from prefect.client.schemas.actions import ArtifactUpdate


@flow
async def report_status():
    artifact_id = await acreate_image_artifact(
        image_url="https://example.com/status-0.png",
        key="status-image",
    )
    async with get_client() as client:
        for percent in (10, 20, 30):
            await client.update_artifact(
                artifact_id,
                ArtifactUpdate(data=f"https://example.com/status-{percent}.png"),
            )
    return artifact_id


artifact_id = asyncio.run(report_status())

Use your real image URLs and perform each update after generating the next status image. The image artifact's data is its URL; the update preserves the existing artifact's ID and image type.

I checked this with Prefect 3.8.8 against a real temporary local API. After the three updates, the API held one artifact with the original ID, type image, and the final status-30.png URL. This checks the artifact record updates; the example URLs are placeholders and I didn't test image loading in the UI.

A shared key groups artifact versions, so creating a new artifact repeatedly with the same key still keeps those versions. Updating a single ID avoids adding those new records. For a simple percentage rather than a graph, Prefect also provides the progress artifact update helper.