local-activities.md

Local Activities

Local activities use the same stub-less pattern as regular activities.

Local Activity Execution

@ActivityInterface
interface ValidationActivities {
    suspend fun validate(input: String): Boolean
    fun sanitize(input: String): String  // Non-suspend also supported
}

val isValid = KWorkflow.executeLocalActivity(
    ValidationActivities::validate,
    KLocalActivityOptions(startToCloseTimeout = 5.seconds),
    input
)

val sanitized = KWorkflow.executeLocalActivity(
    ValidationActivities::sanitize,
    KLocalActivityOptions(startToCloseTimeout = 1.seconds),
    input
)

KWorkflow Local Activity Methods

object KWorkflow {
    /**
     * Execute a local activity with type-safe method reference.
     */
    suspend fun <T, A1, R> executeLocalActivity(
        activity: KFunction2<T, A1, R>,
        options: KLocalActivityOptions,
        arg1: A1
    ): R

    suspend fun <T, R> executeLocalActivity(
        activity: KFunction1<T, R>,
        options: KLocalActivityOptions
    ): R

    // ... up to 6 arguments
}

KLocalActivityOptions

/**
 * Kotlin-native local activity options.
 */
data class KLocalActivityOptions(
    val startToCloseTimeout: Duration? = null,
    val scheduleToCloseTimeout: Duration? = null,
    val scheduleToStartTimeout: Duration? = null,
    val localRetryThreshold: Duration? = null,
    val retryOptions: KRetryOptions? = null,
    val doNotIncludeArgumentsIntoMarker: Boolean = false,
    // Experimental
    @Experimental val summary: String? = null
)

KActivity.executionContext in Local Activities

KActivity.executionContext is available in local activities with limited functionality:

Feature	Local Activity Behavior
context.info	Works (info.isLocal returns true)
context.heartbeat()	No-op (ignored)
context.heartbeatDetails<T>()	Returns null
context.taskToken	Throws UnsupportedOperationException
context.doNotCompleteOnReturn()	Throws UnsupportedOperationException

Related

• Activity Definition - Interface patterns
• Activity Implementation - Full implementation details

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