workflow/docs/api-reference/workflow-errors/workflow-run-failed-error.mdx

Workflow SDK - Build durable, resilient, and observable workflows

---
title: WorkflowRunFailedError
description: Thrown when awaiting the return value of a failed workflow run.
type: reference
summary: Catch WorkflowRunFailedError when awaiting run.returnValue on a run that encountered a fatal error.
related:
  - /docs/api-reference/workflow/fatal-error
  - /docs/api-reference/workflow-errors/workflow-run-cancelled-error
  - /docs/api-reference/workflow-errors/workflow-run-not-found-error
---

`WorkflowRunFailedError` is thrown when awaiting `run.returnValue` on a workflow run whose status is `'failed'`. This indicates that the workflow encountered a fatal error during execution and cannot produce a return value.

The `cause` property contains the underlying error with its message, stack trace, and optional error code.

```typescript lineNumbers
import { WorkflowRunFailedError } from "workflow/errors"
declare const run: { status: Promise<string>; returnValue: Promise<any> }; // @setup

try {
  const result = await run.returnValue;
} catch (error) {
  if (WorkflowRunFailedError.is(error)) { // [!code highlight]
    console.error(`Run ${error.runId} failed:`, error.cause.message);
    if (error.cause.code) {
      console.error("Error code:", error.cause.code);
    }
  }
}
```

## API Signature

### Properties

<TSDoc
definition={`
interface WorkflowRunFailedError {
  /** The ID of the failed run. */
  runId: string;
  /** The underlying error that caused the failure. */
  cause: Error & { code?: string };
  /** The error message. */
  message: string;
}
export default WorkflowRunFailedError;`}
/>

### Static Methods

#### `WorkflowRunFailedError.is(value)`

Type-safe check for `WorkflowRunFailedError` instances. Preferred over `instanceof` because it works across module boundaries and VM contexts.

```typescript
import { WorkflowRunFailedError } from "workflow/errors"
declare const error: unknown; // @setup

if (WorkflowRunFailedError.is(error)) {
  // error is typed as WorkflowRunFailedError
}
```