Artifact and asset events

Artifact events track individual artifact creation and updates. Artifact collection events track the lifecycle of keyed artifact collections. Asset events track data lineage through upstream references and downstream materializations.

Artifact collection events

An artifact collection groups all artifacts that share the same key. Collection lifecycle events are emitted when that collection is created, updated (the latest artifact changes), or deleted (all artifacts for the key are removed).

prefect.artifact-collection.created

Emitted when a keyed artifact collection is first created (that is, when the first artifact with a given key is written).

Resource

Label	Description
prefect.resource.id	prefect.artifact-collection.{uuid}
prefect.resource.name	Artifact key

Related resources

Resource ID pattern	Role	When present
prefect.artifact.{uuid}	latest	The artifact that is currently the latest version in this collection
prefect.flow-run.{uuid}	flow-run	When the artifact was created by a flow run
prefect.task-run.{uuid}	task-run	When the artifact was created by a task run

Payload

Field	Type	Description
key	string	Artifact key
type	string or null	Artifact type (for example, markdown, table, progress, image)
data	any or null	Artifact data
description	string or null	Artifact description

prefect.artifact-collection.updated

Emitted when the latest artifact in a collection changes (for example, a new artifact with the same key is written).

Resource

Same as prefect.artifact-collection.created.

Related resources

Same as prefect.artifact-collection.created, reflecting the new latest artifact.

Payload

Same as prefect.artifact-collection.created.

prefect.artifact-collection.deleted

Emitted when all artifacts for a key are removed and the collection is deleted.

Resource

Same as prefect.artifact-collection.created.

Related resources

Same as prefect.artifact-collection.created.

Payload

Same as prefect.artifact-collection.created.

Artifact events

prefect.artifact.created

Emitted when a new artifact is created.

Resource

Label	Description
prefect.resource.id	prefect.artifact.{uuid}
prefect.resource.name	Artifact key (when set)

Related resources

This event has no related resources.

Payload

Field	Type	Description
key	string or null	Artifact key
type	string or null	Artifact type (for example, markdown, table, progress, image)
description	string or null	Artifact description

prefect.artifact.updated

Emitted when an existing artifact is updated.

Resource

Label	Description
prefect.resource.id	prefect.artifact.{uuid}

Related resources

This event has no related resources.

Payload

The payload contains the fields that were updated, serialized from the update model. Common fields include data, description, and type.

Asset events

For more on assets and data lineage, see Assets.

prefect.asset.referenced

Emitted for each upstream asset referenced during a task execution. One event is emitted per upstream asset.

Resource

Label	Description
prefect.resource.id	Asset key (the unique identifier for the asset, for example s3://bucket/path)
prefect.resource.name	Asset name (when set via asset properties)
prefect.asset.description	Asset description (when set)
prefect.asset.url	Asset URL (when set)
prefect.asset.owners	JSON-encoded list of asset owners (when set)

Related resources

This event has no related resources.

Payload

This event has no payload.

prefect.asset.materialization.succeeded

Emitted when a downstream asset is successfully materialized (the task that produces it completes).

Resource

Same labels as prefect.asset.referenced.

Related resources

Resource ID pattern	Role	When present
Asset key	asset	One entry per upstream asset (both direct and inherited)
Materialized-by identifier	asset-materialized-by	When a materialized_by identifier was specified

Payload

User-provided materialization metadata, if any was supplied via the asset's materialization_metadata parameter. This is an open-ended dictionary.

prefect.asset.materialization.failed

Emitted when a downstream asset fails to materialize (the task that produces it fails). Same structure as prefect.asset.materialization.succeeded.

Resource

Same labels as prefect.asset.referenced.

Related resources

Same as prefect.asset.materialization.succeeded.

Payload

Same as prefect.asset.materialization.succeeded.