CloudFlow connects your workflows to other Alibaba Cloud services, letting each flow step call API operations and act on cloud resources directly. Two concepts control how these connections work: integration types determine the level of optimization applied to API calls, and integration modes determine how a flow handles task responses.
Integration types
CloudFlow supports two integration types: normal and optimized. If a service supports both, use optimized integration.
Normal integration
Normal integration calls the unmodified API operations of any Alibaba Cloud service through OpenAPI. Up to tens of thousands of API operations are available across the full service catalog.
Use normal integration when:
The target service does not offer optimized integration.
You need an API operation that optimized integration does not cover.
Optimized integration
Optimized integration wraps frequently used API operations with additional logic before calling them through OpenAPI. Compared with normal integration, optimized integration provides the following benefits:
Simpler flow definitions with fewer required parameters.
Built-in support for asynchronous callback modes (WaitForSystemCallback and WaitForCustomCallback).
For services that CloudFlow cannot access directly through OpenAPI, optimized integration uses SDKs or public clients instead.
The CloudFlow console Workflow Studio provides optimized integration options in its visual designer. For details, see Interface overview.
Services with optimized integration
Configure these integrations in task-type states using flow definition language (FDL):
| Service | What you can do |
|---|---|
| Function Compute (FC) | Invoke a function |
| CloudFlow | Invoke and run a flow |
| Short Message Service (SMS) | Send messages to phone numbers |
| Message Service (MNS) | Send messages to topics or queues |
| EventBridge | Deliver events to a bus |
| Object Storage Service (OSS) | Write objects to a bucket |
| HTTP | Send an HTTP request to a URL |
Integration modes
Integration modes control how a flow handles the response from a task. CloudFlow supports three modes. For full details, see Service integration modes.
RequestComplete (default)
The flow calls the target service, uses the return value as the task result, and moves to the next step immediately. This mode works like a standard synchronous API call.
WaitForSystemCallback
The flow calls the target service and then pauses. When the target service finishes processing, the system automatically sends a callback to resume the flow. Use this mode for long-running operations where the called service signals completion on its own, such as invoking a CloudFlow sub-flow or a Function Compute function.
WaitForCustomCallback
The flow calls the target service and then pauses. Your application or an external system sends the callback to resume the flow. Use this mode when a step requires human approval, third-party processing, or any action outside the Alibaba Cloud service boundary.
Integration mode support by service and workflow type
Both standard and express workflow modes support normal and optimized integration. However, they differ in which integration modes are available:
Standard workflow mode supports all three integration modes: RequestComplete, WaitForSystemCallback, and WaitForCustomCallback.
Express workflow mode supports RequestComplete only.
For a full comparison of standard and express workflow modes, see Mode comparisons.
The following table shows which integration modes each service supports. All services support RequestComplete. The two callback modes are available only for specific services and only in standard workflow mode.
| Integration type | Service | RequestComplete | WaitForSystemCallback | WaitForCustomCallback |
|---|---|---|---|---|
| Optimized | Function Compute | Standard and express | Standard | Standard |
| Optimized | CloudFlow | Standard and express | Standard | Standard |
| Optimized | EventBridge | Standard and express | Not supported | Standard |
| Optimized | Message Service (MNS) | Standard and express | Not supported | Standard |
| Optimized | HTTP | Standard and express | Not supported | Standard |
| Optimized | Short Message Service (SMS) | Standard and express | Not supported | Standard |
| Optimized | Object Storage Service (OSS) | Standard and express | Not supported | Not supported |
| Normal | All Alibaba Cloud services | Standard and express | Not supported | Not supported |