---
description: Workflow instances now support a .subscribe() method, which let Workers and applications consume events as instances run.
title: Stream Workflow instance events in your Worker or via the API with .subscribe()
image: https://developers.cloudflare.com/changelog/post/2026-09-15-instance-event-subscriptions/og.png?v=fbf5981d7f99625f
---

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September 15, 2026

## Stream Workflow instance events in your Worker or via the API with .subscribe()

[Workflows](https://developers.cloudflare.com/workflows/) [Workers](https://developers.cloudflare.com/workers/)

Copy as Markdown| [View as Markdown](https://developers.cloudflare.com/changelog/post/2026-09-15-instance-event-subscriptions/index.md)| [Agent setup](https://developers.cloudflare.com/agent-setup/)

You can now stream Workflow instance events via `WorkflowInstance.subscribe()` and the `GET /subscribe` API endpoint. Workers and HTTP clients can react to [workflow](https://developers.cloudflare.com/workflows/build/events-and-parameters/) and [step](https://developers.cloudflare.com/workflows/build/step-context/#workflowstepcontext) events, including attempts, sleeps, waits, and rollbacks, without polling for instance status.

A subscription first streams the entire event history of the Workflow instance. After streaming past events, the subscription waits for new events as the instance runs. You can use `filter` to receive only specific event types or `cursor` to start a subscription at a specific event.

Use `.subscribe()` to update Workflow status in user-facing dashboards, send notifications when steps complete, or trigger follow-up work for specific events.

```js
const instance = await env.MY_WORKFLOW.get("report-123");

using subscription = await instance.subscribe();

while (true) {
	const { value, done } = await subscription.next();
	if (done) {
		break;
	}

	console.log(value.type, value);
}
```

```ts
const instance = await env.MY_WORKFLOW.get("report-123");

using subscription = await instance.subscribe();

while (true) {
	const { value, done } = await subscription.next();
	if (done) {
		break;
	}

	console.log(value.type, value);
}
```

For event types, available fields, and subscription options, refer to [Subscribe to events](https://developers.cloudflare.com/workflows/build/subscribe-to-instance-events/).

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