---
title: "Cloudflare Workflows"
description: "Learn how to add Sentry instrumentation for Cloudflare Workflows."
url: https://docs.sentry.io/platforms/javascript/guides/cloudflare/features/workflows/
---

# Cloudflare Workflows | Sentry for Cloudflare

*(Available in version [9.32.0](https://github.com/getsentry/sentry-javascript/releases/tag/9.32.0) and above)*

You can use the `instrumentWorkflowWithSentry` method to instrument [Cloudflare Workflows](https://developers.cloudflare.com/workflows/).

Because workflows can be hibernated and lose all state, we use the workflows `instanceId` to generate the Sentry `trace_id` to link all steps together into a single trace. If `instanceId` is a UUID (with or without dashes), it will be used directly as the `trace_id`. If not, we SHA1 hash the `instanceId` to generate a deterministic `trace_id`.

We use the last 4 characters of the `trace_id` for sampling to ensure all steps have the same sampling decision.

Because the `instanceId` is used for both the `trace_id` and for sampling decisions, you should ensure that the `instanceId` is unique for each workflow instance. If you are using custom UUIDs, you should ensure the last 4 digits are sufficiently random to ensure a good distribution of sampling decisions.

We recommend creating spans only inside `step.do()` callbacks. Due to the nature of Cloudflare Workflows, a workflow can be hibernated and resumed at any point. When a workflow resumes, its `run` method is executed again from the beginning. `step.do()` calls are idempotent and won't re-run completed steps, but any code outside of them will be re-executed. This can lead to duplicated spans and unexpected behavior if you start spans at the top level of your `run` method.

```typescript
import {
  WorkflowEntrypoint,
  WorkflowStep,
  WorkflowEvent,
} from "cloudflare:workers";
import * as Sentry from "@sentry/cloudflare";

class MyWorkflowBase extends WorkflowEntrypoint<Env, Params> {
  async run(event: WorkflowEvent<Params>, step: WorkflowStep) {
    await step.do("fetch data", async () => {
      //
    });

    await step.do("process data", async () => {
      //
    });
  }
}

// Export your named class as defined in your wrangler config
export const MyWorkflow = Sentry.instrumentWorkflowWithSentry(
  (env: Env) => ({
    dsn: "___PUBLIC_DSN___",
    tracesSampleRate: 1.0,
  }),
  MyWorkflowBase,
);
```