workflow/docs/comparisons/index.mdx

Workflow SDK - Build durable, resilient, and observable workflows

---
title: Comparisons
description: 'How the Workflow SDK compares to other durable execution, workflow, and AI-agent frameworks: Temporal, Cloudflare Workflows, AWS Step Functions, AWS Bedrock AgentCore, Inngest, and trigger.dev.'
type: overview
summary: Side-by-side comparisons of the Workflow SDK against Temporal, Cloudflare Workflows, AWS Step Functions, AWS Bedrock AgentCore, Inngest, and trigger.dev.
related:
  - /docs/foundations/workflows-and-steps
  - /docs/how-it-works/event-sourcing
  - /worlds/vercel
---

The Workflow SDK overlaps with several categories: durable execution engines, background-job platforms, managed orchestrators, and AI-agent runtimes. This section compares it against the most common alternatives, one deep dive per tool.

## What makes the Workflow SDK different

- **It's an open-source SDK, not a hosted product.** Your workflows are plain TypeScript in your existing app. Run them on the managed [Vercel World](/worlds/vercel), or self-host on the [Postgres World](/worlds/postgres). The [World abstraction](/worlds/building-a-world) lets you own and swap the storage, queue, and streaming layers independently.
- **Versioning is safe by default.** Runs are pinned to the immutable deployment that started them, so shipping new code never disturbs in-flight runs. Upgrading a run is explicit and opt-in. See [Versioning](/docs/comparisons/workflow-sdk-vs-temporal#versioning).
- **Real-time durable streaming is built in.** Stream partial output, such as large language model (LLM) tokens and progress, to clients with [streams](/docs/foundations/streaming) that survive reconnects, cold starts, and replays. This durability supports chat and agent UIs.
- **First-class AI agents.** `WorkflowAgent` ships inside the [AI SDK](/docs/ai), turning an agent loop into a durable workflow with automatic step retries and human-in-the-loop pauses.

## Snapshot

<Callout type="info">
These comparisons are compiled from each product's public documentation and are **not** based on head-to-head benchmarks: durable engines differ enough that a single number rarely compares cleanly. Treat them as directional and verify current pricing and limits against each vendor's docs.
</Callout>

| Tool | Category | Durability model | Open source / self-host | Language(s) |
| --- | --- | --- | --- | --- |
| **Workflow SDK** | Durable functions SDK | Event-log + deterministic replay | ✅ Apache-2.0: self-host (Postgres) or Vercel | TypeScript (Python beta) |
| [Temporal](/docs/comparisons/workflow-sdk-vs-temporal) | Durable execution platform | Event-sourced replay | ✅ MIT server: self-host or Temporal Cloud | Go, Java, TypeScript, Python, .NET, PHP, Ruby |
| [Cloudflare Workflows](/docs/comparisons/workflow-sdk-vs-cloudflare-workflows) | Durable execution engine | Step-result memoization + replay | ❌ Cloudflare-only | TypeScript (Python beta) |
| [AWS Step Functions](/docs/comparisons/workflow-sdk-vs-aws-step-functions) | Managed state-machine orchestrator | Declarative ASL state machine | ❌ AWS-only | ASL JSON (tasks: any language) |
| [AWS Bedrock AgentCore](/docs/comparisons/workflow-sdk-vs-aws-agentcore) | AI-agent hosting platform | Not durable execution (ephemeral sessions) | ❌ AWS-only | Python, Node.js |
| [Inngest](/docs/comparisons/workflow-sdk-vs-inngest) | Durable functions / event platform | Step-result memoization | ◑ SSPL: self-host (community/best-effort) or SaaS | TypeScript (Python/Go pre-1.0) |
| [trigger.dev](/docs/comparisons/workflow-sdk-vs-trigger-dev) | Durable task platform | Process checkpoint/restore (CRIU) | ✅ Apache-2.0: self-host or Cloud | TypeScript only |

## Deep dives

<Cards>
    <Card href="/docs/comparisons/workflow-sdk-vs-temporal" title="vs Temporal">
        The mature, language-agnostic durable-execution platform. You run the workers; Workflow SDK runs in your app.
    </Card>
    <Card href="/docs/comparisons/workflow-sdk-vs-cloudflare-workflows" title="vs Cloudflare Workflows">
        A durable engine on Workers and Durable Objects. Both replay; they handle versioning and encryption differently.
    </Card>
    <Card href="/docs/comparisons/workflow-sdk-vs-aws-step-functions" title="vs AWS Step Functions">
        Declarative ASL JSON state machines compared with plain TypeScript control flow.
    </Card>
    <Card href="/docs/comparisons/workflow-sdk-vs-aws-agentcore" title="vs AWS Bedrock AgentCore">
        An AI-agent hosting platform, not a durable-execution engine. Different axis.
    </Card>
    <Card href="/docs/comparisons/workflow-sdk-vs-inngest" title="vs Inngest">
        Event-driven durable functions that run on your own infrastructure over HTTP.
    </Card>
    <Card href="/docs/comparisons/workflow-sdk-vs-trigger-dev" title="vs trigger.dev">
        A TypeScript task platform that achieves durability by snapshotting the process (CRIU).
    </Card>
</Cards>

<Callout type="info">
Each deep dive includes a concept-mapping section for moving an existing system. The Workflow SDK migration skill can translate code for you:

```bash
npx skills add https://github.com/vercel/workflow --skill migrating-to-workflow-sdk
```
</Callout>