Step Functions

MicroStack includes a full AWS States Language (ASL) execution engine supporting all state types.

Supported State Types

• Pass — Inject fixed results or transform input
• Task — Invoke Lambda functions or mock responses
• Choice — Conditional branching with comparison operators
• Wait — Time-based delays (seconds, timestamp)
• Parallel — Execute branches concurrently
• Map — Iterate over arrays
• Succeed — Terminal success state
• Fail — Terminal failure with error/cause

Mock Configuration

Configure mock responses for Task states via the config endpoint:

curl -X POST http://localhost:4566/_microstack/config \
  -H 'Content-Type: application/json' \
  -d '{
    "stepfunctions": {
      "_sfn_mock_config": {
        "StateMachines": {
          "MyStateMachine": {
            "TestCases": {
              "HappyPath": {
                "LambdaInvoke": {
                  "0": { "Return": {"result": "ok"} }
                }
              }
            }
          }
        }
      }
    }
  }'