> ## Documentation Index
> Fetch the complete documentation index at: https://docs.agentfront.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Workflow Errors

> Error classes for multi-step workflow execution

These errors surface from the workflow runtime when a multi-step DAG fails to validate or complete. All inherit from `InternalMcpError` (not safe to surface verbatim to clients — the runtime maps them to a generic JSON-RPC error before sending).

## Reference

| Class                        | Inherits           | When                                                         |
| ---------------------------- | ------------------ | ------------------------------------------------------------ |
| `WorkflowStepNotFoundError`  | `InternalMcpError` | A step alias was referenced before it completed              |
| `WorkflowTimeoutError`       | `InternalMcpError` | The whole workflow exceeded its `timeoutMs`                  |
| `WorkflowDagValidationError` | `InternalMcpError` | The declared DAG had a cycle, missing dependency, or bad ref |
| `WorkflowJobTimeoutError`    | `InternalMcpError` | An individual job step exceeded its `timeoutMs`              |

## Usage

```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
import {
  WorkflowStepNotFoundError,
  WorkflowTimeoutError,
  WorkflowDagValidationError,
  WorkflowJobTimeoutError,
} from '@frontmcp/sdk';

// Inside a workflow runtime extension
if (!completed.has(alias)) {
  throw new WorkflowStepNotFoundError(alias);
}
```

## Related

* [Workflows](/frontmcp/servers/workflows) — declare multi-step workflows
* [Jobs](/frontmcp/servers/jobs) — long-running jobs invoked by workflow steps
* [Errors Overview](/frontmcp/sdk-reference/errors/overview)