Signals

HandlerContext.waitForSignal records a durable boundary and releases the lease. When another process delivers the named signal, Workhorse makes the same logical attempt ready and restarts the handler from its entry point.

const approval = await context.waitForSignal<{ approved: boolean }>("approval");
if (approval.approved) await publishOrder();

Checkpoint earlier effects because replay starts from the top. When replay reaches the same name, waitForSignal returns the retained payload.

Go handlers can pass ExternalWaitOptions when the boundary needs a shorter lifetime. Python handlers pass timeout_ms for the same boundary.

Deliver once, retry safely

Applications call Queue.sendSignal(jobId, name, payload, request) with an idempotency key and a trusted actor. An equivalent network retry returns the retained delivery. Reusing a key with changed payload or attribution conflicts, and a competing late delivery returns the accepted winner without resuming the handler again.

If another transition has already closed the boundary, the delivery returns stale and leaves the retained outcome unchanged.

A delivery before the wait exists is rejected rather than buffered. A timeout, job deadline, or cancellation closes the boundary, so replay cannot continue with an invented payload.

Admin.listSignalWaits() provides the actionable operator projection. The dashboard uses the same public method, but its server replaces browser-supplied attribution with the authenticated actor.

Go applications deliver through Queue.SendSignal with ExternalWaitDelivery. The returned SignalDeliveryResult contains the database status and retained payload.

TypeScript handlers call ctx.waitForSignal and pass timeoutMs when the wait needs a deadline. Go uses HandlerContext.WaitForSignal; both return a nextCursor that prevents an earlier signal from being consumed again.

Next

• Human waits — collect an operator decision with stored context
• Durable execution — understand handler replay
• Agentic flow — wait for approval inside a durable loop

Exact signal statuses, bounds, and transitions: architecture reference.