---
title: "workflow"
description: Core workflow primitives for steps, streaming, webhooks, and error handling.
type: overview
summary: Explore the core workflow package for steps, streaming, hooks, and error handling.
related:
  - /docs/foundations/workflows-and-steps
  - /docs/foundations/hooks
  - /docs/foundations/streaming
  - /docs/foundations/errors-and-retries
---

Core workflow primitives including steps, context management, streaming, webhooks, and error handling.

## Installation

```package-install
npm i workflow
```

## Functions

Workflow SDK contains the following functions you can use inside your workflow functions:

<Cards>
    <Card href="/docs/api-reference/workflow/get-workflow-metadata" title="getWorkflowMetadata()">
        A function that returns context about the current workflow execution.
    </Card>
    <Card href="/docs/api-reference/workflow/get-step-metadata" title="getStepMetadata()">
        A function that returns context about the current step execution.
    </Card>
    <Card href="/docs/api-reference/workflow/sleep" title="sleep()">
        Sleeping workflows for a specified duration. Deterministic and replay-safe.
    </Card>
    <Card href="/docs/api-reference/workflow/fetch" title="fetch()">
        Make HTTP requests from within a workflow with automatic retry semantics.
    </Card>
    <Card href="/docs/api-reference/workflow/create-hook" title="createHook()">
        Create a low-level hook to receive arbitrary payloads from external systems.
    </Card>
    <Card href="/docs/api-reference/workflow/define-hook" title="defineHook()">
        Type-safe hook helper for consistent payload types.
    </Card>
    <Card href="/docs/api-reference/workflow/create-webhook" title="createWebhook()">
        Create a webhook that suspends the workflow until an HTTP request is received.
    </Card>
    <Card href="/docs/api-reference/workflow/get-writable" title="getWritable()">
        Access the current workflow run's default stream.
    </Card>
</Cards>

## Error Classes

Workflow SDK includes error classes that can be thrown in a workflow or step to change the error exit strategy of a workflow.

<Cards>
    <Card href="/docs/api-reference/workflow/fatal-error" title="FatalError()">
        When thrown, marks a step as failed and the step is not retried.
    </Card>
    <Card href="/docs/api-reference/workflow/retryable-error" title="RetryableError()">
        When thrown, marks a step as retryable with an optional parameter.
    </Card>
</Cards>