Declarative Automation: Operators

Declarative Automation: Operators

Operators combine operands and other conditions into complex expressions using boolean logic and transformations.

Boolean Operators

& (AND): Both conditions must be true:

import dagster as dg

condition = (
    dg.AutomationCondition.newly_updated()
    & ~dg.AutomationCondition.in_progress()
)

| (OR): Either condition must be true:

condition = (
    dg.AutomationCondition.missing()
    | dg.AutomationCondition.newly_updated()
)

~ (NOT): Negates the condition:

condition = ~dg.AutomationCondition.any_deps_missing()

Transformation Operators

since(reset_condition)

Converts events into status. Becomes true when the operand becomes true and remains true until the reset condition becomes true.

# True from when dependency updates until asset is requested
condition = dg.AutomationCondition.any_deps_updated().since(
    dg.AutomationCondition.newly_requested()
)

Pattern: A.since(B) means "A has occurred more recently than B"

Use case: Create persistent states from transient events. "Upstream updated" is an event, but "upstream updated since I was last requested" is a status.

newly_true()

Converts status into an event. True only on the tick when the operand transitions from false to true.

# True only on the tick when the asset becomes missing
condition = dg.AutomationCondition.missing().newly_true()

Use case: Prevent repeated actions during persistent states. missing() stays true for many ticks, but missing().newly_true() is only true once.

since_last_handled()

Convenience method equivalent to .since(newly_requested() | newly_updated() | initial_evaluation()).

condition = dg.AutomationCondition.any_deps_updated().since_last_handled()

True from when the condition becomes true until the asset is requested, updated, or the condition is first applied.

Dependency Operators

any_deps_match(condition)

True if the condition is true for at least one partition of any upstream dependency.

condition = dg.AutomationCondition.any_deps_match(
    dg.AutomationCondition.missing()
)

Supports filtering with .allow() and .ignore().

all_deps_match(condition)

True if the condition is true for at least one partition of all upstream dependencies.

condition = dg.AutomationCondition.all_deps_match(
    dg.AutomationCondition.newly_updated()
)

Requires every upstream asset to have at least one partition matching the condition.

Dependency Filtering

allow(selection)

Restricts which dependencies are checked to only those in the AssetSelection:

# Only consider dependencies in the "important" group
condition = dg.AutomationCondition.any_deps_match(
    dg.AutomationCondition.missing()
).allow(dg.AssetSelection.groups("important"))

Creates an intersection: dep_keys & allowed_selection

ignore(selection)

Excludes dependencies in the AssetSelection from being checked:

# Ignore the "foo" asset when checking for updates
condition = dg.AutomationCondition.any_deps_updated().ignore(
    dg.AssetSelection.assets("foo")
)

Creates a subtraction: dep_keys - ignored_selection

Propagation Through Boolean Operators

When applied to AND/OR conditions, .allow() and .ignore() propagate to all sub-conditions:

# Applies allow() to all dependency checks within eager()
condition = dg.AutomationCondition.eager().allow(
    dg.AssetSelection.groups("critical")
)

Check Operators

any_checks_match(condition, blocking_only)

True if any of the asset's checks match the condition.

condition = dg.AutomationCondition.any_checks_match(
    dg.AutomationCondition.check_failed(),
    blocking_only=True,
)

Parameters:

• condition: Condition to evaluate against checks
• blocking_only (bool): If True, only considers blocking checks (default: False)

all_checks_match(condition, blocking_only)

True if all of the asset's checks match the condition.

condition = dg.AutomationCondition.all_checks_match(
    dg.AutomationCondition.check_passed(),
    blocking_only=True,
)

Labeling

with_label(label)

Adds a human-readable label to a condition for debugging and UI display:

condition = (
    dg.AutomationCondition.any_deps_updated()
    .since(dg.AutomationCondition.newly_requested())
).with_label("updated_since_requested")

Labels appear in condition evaluation traces in the Dagster UI, making complex conditions easier to understand.