Standard vs. Express API support— the missing side-by-side comparison
Published on 19 October 2021.
AWS Step Functions come in two flavours: Standard and Express. They share a definition language called ASL, but a lot of the API operations are not supported across both types. I didn’t find a good side-by-side comparison showing the support for each individual API operation, so I made one. This could help you decide if your Standard workflows could be replaced by Express workflows.
There is a good side-by-side comparison for an overview of the two types of workflow. Understanding those differences helps to explain why certain operations are not supported.
Takeaways
- Activities and the Callback pattern are not supported.
- Execution data is not available via the Step Functions API, only via CloudWatch Logs.
- Thinking of Express workflows as “ASL executed on Lambda” was a decent mental model.
| Category | Operation | Standard | Express |
|---|---|---|---|
| State Machine | createStateMachine | ✅ | ✅ |
| updateStateMachine | ✅ | ✅ | |
| deleteStateMachine | ✅ | ✅ | |
| describeStateMachine | ✅ | ✅ | |
| listStateMachines | ✅ | ✅ | |
| Execution | startExecution | ✅ | ✅ |
| startSyncExecution | ❌ | ✅ | |
| stopExecution | ✅ | ❌ | |
| getExecutionHistory | ✅ | ❌ | |
| describeExecution | ✅ | ❌ | |
| listExecutions | ✅ | ❌ | |
| describeStateMachineForExecution | ✅ | ❌ | |
| Activities | createActivity | ✅ | ❌ |
| deleteActivity | ✅ | ❌ | |
| listActivities | ✅ | ❌ | |
| describeActivity | ✅ | ❌ | |
| getActivityTask | ✅ | ❌ | |
| Callback | sendTaskFailure | ✅ | ❌ |
| sendTaskSuccess | ✅ | ❌ | |
| sendTaskHeartbeat | ✅ | ❌ | |
| Tags | tagResource | ✅ | ✅ |
| untagResource | ✅ | ✅ | |
| listTagsForResource | ✅ | ✅ |
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ABOUT GRUNDLEFLECK
Graham "Grundlefleck" Allan is a Software Developer living in Scotland. His only credentials as an authority on software are that he has a beard. Most of the time.