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Kotlin Extensions

DBOS ships Kotlin extension functions on the DBOS class in the dev.dbos.transact package. They place the lambda argument last so Kotlin's trailing lambda syntax works naturally. All extensions are @JvmSynthetic and invisible to Java callers.

Extensions​

runStep​

fun <T> DBOS.runStep(options: StepOptions, block: () -> T): T
fun <T> DBOS.runStep(name: String, block: () -> T): T

Kotlin-friendly alternatives to dbos.runStep that place the lambda last.

Parameters:

  • options: A StepOptions object controlling the step name and retry policy.
  • name: The step name as a plain string (shorthand for StepOptions(name)).
  • block: The step body. Must be deterministic across retries; side effects and external calls belong here rather than in the workflow body.

Example:

// with a name
val result = dbos.runStep("fetchData") {
    httpClient.get(url)
}

// with options (e.g. retries)
val result = dbos.runStep(StepOptions("fetchData").withMaxAttempts(3)) {
    httpClient.get(url)
}

startWorkflow​

fun <T> DBOS.startWorkflow(options: StartWorkflowOptions?, block: () -> T): WorkflowHandle<T, Exception>

Kotlin-friendly alternative to dbos.startWorkflow that places the lambda last. Pass null for options to use defaults.

note

A zero-argument startWorkflow { } extension is not provided because Kotlin's SAM conversion causes the Java member to win before any extension is considered for that signature. Always supply StartWorkflowOptions() (or null) as the first argument.

Parameters:

  • options: StartWorkflowOptions controlling workflow ID, queue, timeout, etc. Pass null to use defaults.
  • block: A call to a registered workflow proxy method.

Returns: A WorkflowHandle for retrieving the workflow result.

Example:

val handle = dbos.startWorkflow(StartWorkflowOptions()) {
    orderProxy.processOrder("order-123")
}
val result = handle.result