AWS Step Functions Cheat Sheet

Updated 2026-05-21

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AWS Step Functions is a fully managed serverless orchestration service that lets you coordinate distributed applications and microservices using visual state machine workflows defined in the Amazon States Language (ASL). It eliminates the need to write custom coordination code for retry logic, error handling, and parallel execution. The critical mental model to grasp early: Step Functions bills Standard Workflows per state transition (not per execution), so workflow design choices — whether to use Express vs. Standard, polling vs. callbacks, or nested child executions — directly shape your monthly cost.

What This Cheat Sheet Covers

This topic spans 17 focused tables and 165 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.

Table 1: State Machine Core ConceptsTable 2: Workflow Types — Standard vs. ExpressTable 3: ASL State TypesTable 4: Service Integration PatternsTable 5: Error Handling — Retry and CatchTable 6: Input and Output ProcessingTable 7: Distributed Map StateTable 8: Nested Workflows and Child ExecutionsTable 9: Callback Pattern and ActivitiesTable 10: Intrinsic Functions (JSONPath)Table 11: Observability and DebuggingTable 12: IAM and SecurityTable 13: Deployment — SAM, CDK, Terraform, and Workflow StudioTable 14: Common Workflow PatternsTable 15: Comparing Step Functions to Azure Durable Functions and Google Cloud WorkflowsTable 16: Cost OptimizationTable 17: Troubleshooting Failed Executions

Table 1: State Machine Core Concepts

The foundational vocabulary of Step Functions is built around state machines, states, and executions. Understanding how executions flow, how input and output travel between states, and what the Amazon States Language (ASL) requires gives you the frame to read and write any workflow definition.

Concept	Example	Description
State Machine	`{"StartAt": "Hello", "States": {...}}`	A JSON (ASL) definition of a workflow — a collection of named states that chain together via `Next` or `End: true`.
State	`"MyState": {"Type": "Task", ...}`	A single step in a workflow; each state has a `Type` and optionally `Next` or `End: true`. State names must be unique within the machine.
Execution	`aws stepfunctions start-execution --state-machine-arn ...`	A single run of a state machine with a specific input. Standard executions retain history for 90 days.
Amazon States Language (ASL)	`{"Comment": "...", "StartAt": "S1", "States": {...}}`	The JSON specification used to define state machines. Files must be saved with `.asl.json` extension outside the console.
`StartAt`	`"StartAt": "FirstState"`	Required top-level field; names the first state to run. Case-sensitive and must match a state name exactly.
`Next`	`"Next": "ProcessData"`	Directs execution to the named next state after this state completes; required unless `End: true`.

Table 1: State Machine Core Concepts

Concept	Example	Description
State Machine	`{"StartAt": "Hello", "States": {...}}`	A JSON (ASL) definition of a workflow — a collection of named states that chain together via `Next` or `End: true`.
State	`"MyState": {"Type": "Task", ...}`	A single step in a workflow; each state has a `Type` and optionally `Next` or `End: true`. State names must be unique within the machine.
Execution	`aws stepfunctions start-execution --state-machine-arn ...`	A single run of a state machine with a specific input. Standard executions retain history for 90 days.
Amazon States Language (ASL)	`{"Comment": "...", "StartAt": "S1", "States": {...}}`	The JSON specification used to define state machines. Files must be saved with `.asl.json` extension outside the console.
`StartAt`	`"StartAt": "FirstState"`	Required top-level field; names the first state to run. Case-sensitive and must match a state name exactly.
`Next`	`"Next": "ProcessData"`	Directs execution to the named next state after this state completes; required unless `End: true`.