tools-only Step Functions Workflow Patterns
Advanced workflow patterns and SDK integrations.
SDK Integrations
Lambda (Optimized)
{
"Type": "Task",
"Resource": "arn:aws:states:::lambda:invoke",
"Parameters": {
"FunctionName": "arn:aws:lambda:us-east-1:123456789012:function:MyFunction",
"Payload.$": "$"
},
"OutputPath": "$.Payload",
"End": true
}
DynamoDB GetItem
{
"Type": "Task",
"Resource": "arn:aws:states:::dynamodb:getItem",
"Parameters": {
"TableName": "Orders",
"Key": {
"order_id": {"S.$": "$.order_id"}
}
},
"ResultPath": "$.order",
"Next": "ProcessOrder"
}
DynamoDB PutItem
{
"Type": "Task",
"Resource": "arn:aws:states:::dynamodb:putItem",
"Parameters": {
"TableName": "Orders",
"Item": {
"order_id": {"S.$": "$.order_id"},
"status": {"S": "processed"},
"processed_at": {"S.$": "$$.State.EnteredTime"}
}
},
"End": true
}
SQS SendMessage
{
"Type": "Task",
"Resource": "arn:aws:states:::sqs:sendMessage",
"Parameters": {
"QueueUrl": "https://sqs.us-east-1.amazonaws.com/123456789012/my-queue",
"MessageBody.$": "States.JsonToString($)"
},
"End": true
}
SNS Publish
{
"Type": "Task",
"Resource": "arn:aws:states:::sns:publish",
"Parameters": {
"TopicArn": "arn:aws:sns:us-east-1:123456789012:my-topic",
"Message.$": "$.message",
"Subject": "Order Notification"
},
"End": true
}
Step Functions (Nested)
{
"Type": "Task",
"Resource": "arn:aws:states:::states:startExecution.sync:2",
"Parameters": {
"StateMachineArn": "arn:aws:states:us-east-1:123456789012:stateMachine:ChildWorkflow",
"Input.$": "$"
},
"End": true
}
ECS RunTask
{
"Type": "Task",
"Resource": "arn:aws:states:::ecs:runTask.sync",
"Parameters": {
"LaunchType": "FARGATE",
"Cluster": "arn:aws:ecs:us-east-1:123456789012:cluster/my-cluster",
"TaskDefinition": "my-task:1",
"NetworkConfiguration": {
"AwsvpcConfiguration": {
"Subnets": ["subnet-12345678"],
"SecurityGroups": ["sg-12345678"],
"AssignPublicIp": "ENABLED"
}
},
"Overrides": {
"ContainerOverrides": [{
"Name": "my-container",
"Environment": [
{"Name": "INPUT", "Value.$": "States.JsonToString($)"}
]
}]
}
},
"End": true
}
EventBridge PutEvents
{
"Type": "Task",
"Resource": "arn:aws:states:::events:putEvents",
"Parameters": {
"Entries": [
{
"Source": "my-app.orders",
"DetailType": "Order Completed",
"Detail.$": "States.JsonToString($)",
"EventBusName": "my-event-bus"
}
]
},
"End": true
}
Callback Pattern
Wait for External Process
{
"Type": "Task",
"Resource": "arn:aws:states:::sqs:sendMessage.waitForTaskToken",
"Parameters": {
"QueueUrl": "https://sqs.us-east-1.amazonaws.com/123456789012/approval-queue",
"MessageBody": {
"token.$": "$$.Task.Token",
"order_id.$": "$.order_id",
"action": "approve_order"
}
},
"TimeoutSeconds": 86400,
"Next": "ProcessApproval"
}
Complete Callback (from external process)
import boto3
sfn = boto3.client('stepfunctions')
# On success
sfn.send_task_success(
taskToken=task_token,
output='{"approved": true, "approver": "user@example.com"}'
)
# On failure
sfn.send_task_failure(
taskToken=task_token,
error='RejectedError',
cause='Order rejected by approver'
)
# Heartbeat (for long-running tasks)
sfn.send_task_heartbeat(taskToken=task_token)
Distributed Map
Process Large Dataset
{
"Type": "Map",
"ItemProcessor": {
"ProcessorConfig": {
"Mode": "DISTRIBUTED",
"ExecutionType": "STANDARD"
},
"StartAt": "ProcessItem",
"States": {
"ProcessItem": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:ProcessItem",
"End": true
}
}
},
"ItemReader": {
"Resource": "arn:aws:states:::s3:getObject",
"ReaderConfig": {
"InputType": "JSON"
},
"Parameters": {
"Bucket": "my-bucket",
"Key": "input/data.json"
}
},
"ResultWriter": {
"Resource": "arn:aws:states:::s3:putObject",
"Parameters": {
"Bucket": "my-bucket",
"Prefix": "output"
}
},
"MaxConcurrency": 1000,
"End": true
}
Intrinsic Functions
String Operations
{
"Type": "Pass",
"Parameters": {
"concatenated.$": "States.Format('Order {} for customer {}', $.order_id, $.customer_id)",
"split.$": "States.StringSplit($.tags, ',')",
"uuid.$": "States.UUID()"
}
}
Array Operations
{
"Type": "Pass",
"Parameters": {
"arrayLength.$": "States.ArrayLength($.items)",
"firstItem.$": "States.ArrayGetItem($.items, 0)",
"range.$": "States.ArrayRange(1, 10, 2)",
"partition.$": "States.ArrayPartition($.items, 10)",
"unique.$": "States.ArrayUnique($.items)"
}
}
JSON Operations
{
"Type": "Pass",
"Parameters": {
"stringified.$": "States.JsonToString($.data)",
"parsed.$": "States.StringToJson($.jsonString)",
"merged.$": "States.JsonMerge($.base, $.override, false)"
}
}
Math Operations
{
"Type": "Pass",
"Parameters": {
"sum.$": "States.MathAdd($.a, $.b)",
"random.$": "States.MathRandom(1, 100)"
}
}
Common Patterns
Saga Pattern (Compensation)
{
"StartAt": "ReserveInventory",
"States": {
"ReserveInventory": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:ReserveInventory",
"Catch": [{
"ErrorEquals": ["States.ALL"],
"Next": "FailOrder"
}],
"Next": "ProcessPayment"
},
"ProcessPayment": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:ProcessPayment",
"Catch": [{
"ErrorEquals": ["States.ALL"],
"ResultPath": "$.error",
"Next": "ReleaseInventory"
}],
"Next": "ShipOrder"
},
"ShipOrder": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:ShipOrder",
"Catch": [{
"ErrorEquals": ["States.ALL"],
"ResultPath": "$.error",
"Next": "RefundPayment"
}],
"End": true
},
"ReleaseInventory": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:ReleaseInventory",
"Next": "FailOrder"
},
"RefundPayment": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:RefundPayment",
"Next": "ReleaseInventory"
},
"FailOrder": {
"Type": "Fail",
"Error": "OrderFailed",
"Cause": "Order processing failed"
}
}
}
Human Approval
{
"StartAt": "SubmitRequest",
"States": {
"SubmitRequest": {
"Type": "Task",
"Resource": "arn:aws:states:::lambda:invoke",
"Parameters": {
"FunctionName": "CreateApprovalRequest",
"Payload.$": "$"
},
"Next": "WaitForApproval"
},
"WaitForApproval": {
"Type": "Task",
"Resource": "arn:aws:states:::lambda:invoke.waitForTaskToken",
"Parameters": {
"FunctionName": "SendApprovalEmail",
"Payload": {
"token.$": "$$.Task.Token",
"request.$": "$"
}
},
"TimeoutSeconds": 604800,
"Catch": [{
"ErrorEquals": ["States.Timeout"],
"Next": "RequestExpired"
}],
"Next": "CheckApproval"
},
"CheckApproval": {
"Type": "Choice",
"Choices": [{
"Variable": "$.approved",
"BooleanEquals": true,
"Next": "ProcessApproved"
}],
"Default": "ProcessRejected"
},
"ProcessApproved": {
"Type": "Succeed"
},
"ProcessRejected": {
"Type": "Fail",
"Error": "Rejected"
},
"RequestExpired": {
"Type": "Fail",
"Error": "Expired"
}
}
}
Polling Pattern
{
"StartAt": "SubmitJob",
"States": {
"SubmitJob": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:SubmitJob",
"Next": "Wait"
},
"Wait": {
"Type": "Wait",
"Seconds": 30,
"Next": "CheckStatus"
},
"CheckStatus": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:CheckJobStatus",
"Next": "IsComplete"
},
"IsComplete": {
"Type": "Choice",
"Choices": [{
"Variable": "$.status",
"StringEquals": "COMPLETED",
"Next": "GetResults"
}, {
"Variable": "$.status",
"StringEquals": "FAILED",
"Next": "JobFailed"
}],
"Default": "Wait"
},
"GetResults": {
"Type": "Task",
"Resource": "arn:aws:lambda:...:function:GetResults",
"End": true
},
"JobFailed": {
"Type": "Fail"
}
}
}