Changelog

Workflows now provides additional context inside step.do() callbacks and supports returning ReadableStream to handle larger step outputs.

The step.do() callback receives a context object with new properties alongside attempt:

• step.name — The name passed to step.do()
• step.count — How many times a step with that name has been invoked in this instance (1-indexed)
  • Useful when running the same step in a loop.
• config — The resolved step configuration, including timeout and retries with defaults applied

type ResolvedStepConfig = {
  retries: {
    limit: number;
    delay: WorkflowDelayDuration | number;
    backoff?: "constant" | "linear" | "exponential";
  };
  timeout: WorkflowTimeoutDuration | number;
};

type WorkflowStepContext = {
  step: {
    name: string;
    count: number;
  };
  attempt: number;
  config: ResolvedStepConfig;
};

Steps can now return a ReadableStream directly. Although non-stream step outputs are limited to 1 MiB, streamed outputs support much larger payloads.

const largePayload = await step.do("fetch-large-file", async () => {
  const object = await env.MY_BUCKET.get("large-file.bin");
  return object.body;
});

Note that streamed outputs are still considered part of the Workflow instance storage limit.