AWS Step Functions
Browse all Amazonaws APIs★ Only Publicly Available OpenAPI DocumentCloud InfrastructureServerlessapiKey26 EndpointsREST
For Agents
Run, monitor, and orchestrate AWS Step Functions state machine executions. Agents can start executions, send task results, fetch execution history, and manage activities and Map runs.
Use for: I need to start a Step Functions execution with a JSON input, Send the result of a long-running task back to a paused state machine, Get the full step-by-step history of a state machine execution, List all state machines in my account
Not supported: Does not run general-purpose code, host containers, or queue messages — use only for orchestrating tasks across other AWS services via state machines.
Jentic publishes the only available OpenAPI specification for AWS Step Functions, keeping it validated and agent-ready. Step Functions coordinates distributed applications and microservices using state machines defined in Amazon States Language (ASL). Agents can create state machines and activities, start standard or express executions, send task success or failure for activity workers, inspect execution history step by step, and run Map runs over large iterables. The 26 operations cover state machines, executions, activities, map runs, and execution history.
Install Jentic One Beta
Connect the AWS Step Functions to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the AWS Step Functions, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
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Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with AWS Step Functions API.
Create and update state machines using Amazon States Language definitions
Start standard or express executions with StartExecution and StartSyncExecution
Send task results from activity workers with SendTaskSuccess, SendTaskFailure, SendTaskHeartbeat
Inspect step-by-step execution history with GetExecutionHistory
Manage activities (long-poll task workers) via CreateActivity and GetActivityTask
Track distributed Map runs via DescribeMapRun and ListMapRuns
Stop a running execution with StopExecution
Use Cases
Patterns agents use AWS Step Functions API for, with concrete tasks.
★ Long-Running Workflow Orchestration
Engineering teams use Step Functions to coordinate multi-step workflows — order processing, data pipelines, ML training — that mix Lambda, ECS, SQS, and human approval steps. CreateStateMachine registers the ASL definition, StartExecution kicks off a run with input JSON, and DescribeExecution plus GetExecutionHistory give complete observability into every state transition.
CreateStateMachine with the ASL definition and roleArn, then StartExecution with stateMachineArn and JSON input, and DescribeExecution to confirm Status=RUNNING.
Activity Worker Integration
When workflows must wait for a human step or an external worker, Step Functions activities are used. CreateActivity registers a queue, workers long-poll with GetActivityTask, and report results via SendTaskSuccess or SendTaskFailure. SendTaskHeartbeat keeps the task alive while work is in progress.
GetActivityTask polling for activityArn, perform the work, then call SendTaskSuccess with the taskToken and a JSON output payload.
Distributed Map for Bulk Processing
Distributed Map mode runs a sub-state-machine across thousands of items in S3 in parallel. Operators use ListMapRuns, DescribeMapRun, and UpdateMapRun to throttle concurrency, track item-level progress, and recover from partial failures.
DescribeMapRun for a mapRunArn returned by an execution, inspect itemsProcessed and toleratedFailureCount, then UpdateMapRun to lower maxConcurrency if the downstream system is overloaded.
AI Agent Workflow Control via Jentic
AI agents using Jentic can launch and inspect Step Functions executions on demand: starting a workflow with a generated input, polling its status, and posting back task results from activity workers. Through Jentic, the agent searches by intent, loads operation schemas, and executes against vault-stored AWS credentials.
Search Jentic for 'start a step functions execution', execute StartExecution with stateMachineArn and JSON input, then poll DescribeExecution until Status is SUCCEEDED, FAILED, or TIMED_OUT.
Key Endpoints
26 endpoints — jentic publishes the only available openapi specification for aws step functions, keeping it validated and agent-ready.
METHOD
PATH
DESCRIPTION
POST
/#X-Amz-Target=AWSStepFunctions.CreateStateMachine
Create a state machine from an ASL definition
POST
/#X-Amz-Target=AWSStepFunctions.DescribeStateMachine
Fetch a state machine's definition and metadata
POST
/#X-Amz-Target=AWSStepFunctions.DescribeExecution
Inspect a single execution's status and output
POST
/#X-Amz-Target=AWSStepFunctions.GetExecutionHistory
Retrieve the step-by-step history of an execution
POST
/#X-Amz-Target=AWSStepFunctions.GetActivityTask
Long-poll for the next activity task
POST
/#X-Amz-Target=AWSStepFunctions.ListExecutions
List executions for a state machine
POST
/#X-Amz-Target=AWSStepFunctions.DescribeMapRun
Inspect a distributed Map run
POST
/#X-Amz-Target=AWSStepFunctions.CreateStateMachine
Create a state machine from an ASL definition
POST
/#X-Amz-Target=AWSStepFunctions.DescribeStateMachine
Fetch a state machine's definition and metadata
POST
/#X-Amz-Target=AWSStepFunctions.DescribeExecution
Inspect a single execution's status and output
POST
/#X-Amz-Target=AWSStepFunctions.GetExecutionHistory
Retrieve the step-by-step history of an execution
POST
/#X-Amz-Target=AWSStepFunctions.GetActivityTask
Long-poll for the next activity task
POST
/#X-Amz-Target=AWSStepFunctions.ListExecutions
List executions for a state machine
POST
/#X-Amz-Target=AWSStepFunctions.DescribeMapRun
Inspect a distributed Map run
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
AWS access keys are stored encrypted in the Jentic vault. Step Functions calls are signed with SigV4 inside Jentic — task tokens, ASL definitions, and execution outputs flow through the call without leaving the vault boundary as raw secrets.
Intent-based discovery
Agents search by intent (for example, 'start a step functions execution' or 'get execution history') and Jentic returns the matching Step Functions operations with input schemas, letting the agent invoke StartExecution or GetExecutionHistory directly.
Time to first call
Direct Step Functions integration: 1-2 days for IAM, SigV4 signing, JSON-RPC envelope handling, and ASL definition packaging. Through Jentic: under 1 hour — search, load schema, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using AWS Step Functions API through Jentic.
Why is there no official OpenAPI spec for AWS Step Functions?
AWS does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call AWS Step Functions via structured tooling. It is validated against the live API and kept up to date. Get started at https://app.jentic.com/sign-up.
What authentication does the AWS Step Functions use?
Step Functions uses AWS Signature Version 4 with IAM credentials and permissions on the states:* actions. Through Jentic, AWS keys live encrypted in the vault and SigV4 signing is performed server-side — the agent never holds the raw credential.
Can I run a Step Functions execution synchronously?
Yes, but only for Express workflows. StartSyncExecution invokes an Express state machine and blocks until completion, returning the output inline. Standard workflows must be started with StartExecution and polled via DescribeExecution.
What are the rate limits for the AWS Step Functions?
Step Functions throttles per-region: StartExecution is roughly 1300 per second on Standard and 6000 per second on Express in commercial regions, while StateTransition counts apply to long-running Standard executions. Throttled calls return ThrottlingException; retry with exponential backoff.
How do I post a task result from an activity worker through Jentic?
Through Jentic, search for 'send task success step functions', load the SendTaskSuccess schema, and execute with the taskToken (received from GetActivityTask) and a JSON output string. SendTaskFailure handles error cases and SendTaskHeartbeat keeps the token alive during long work.
Is AWS Step Functions free?
Step Functions Standard charges per state transition (a free tier of 4,000 transitions per month applies). Express workflows are billed per request and per duration. See https://aws.amazon.com/step-functions/pricing/ for the current rates.
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