workflow/docs/api-reference/workflow-errors/workflow-run-not-found-error.mdx

Workflow SDK - Build durable, resilient, and observable workflows

---
title: WorkflowRunNotFoundError
description: Thrown when operating on a workflow run that does not exist.
type: reference
summary: Catch WorkflowRunNotFoundError when performing operations on a non-existent workflow run.
related:
  - /docs/api-reference/workflow-errors/workflow-run-failed-error
  - /docs/api-reference/workflow-errors/workflow-run-cancelled-error
---

`WorkflowRunNotFoundError` is thrown when performing operations on a workflow run that does not exist. This includes calling methods like `run.status`, `run.cancel()`, or awaiting `run.returnValue` on a run whose ID does not match any known workflow run.

Note that `getRun(id)` itself is synchronous and will not throw — the error is raised when subsequent operations on the run object discover the run is missing.

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

try {
  const status = await run.status;
} catch (error) {
  if (WorkflowRunNotFoundError.is(error)) { // [!code highlight]
    console.error(`Run ${error.runId} does not exist`);
  }
}
```

## API Signature

### Properties

<TSDoc
definition={`
interface WorkflowRunNotFoundError {
  /** The ID of the run that was not found. */
  runId: string;
  /** The error message. */
  message: string;
}
export default WorkflowRunNotFoundError;`}
/>

### Static Methods

#### `WorkflowRunNotFoundError.is(value)`

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

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

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