Step Functions state size limits.

AWS Step Functions is a serverless orchestration service that allows you to coordinate and manage the components of your application as a series of steps in a visual workflow. Each state in a Step Function has certain limits regarding the amount of data that can be passed between states. As of my last knowledge update in September 2021, here are the size limits for Step Functions states:

1. Input Size Limit:
   • The maximum size for the input to a state in Step Functions is 32,768 characters (32KB).
2. Output Size Limit:
   • The maximum size for the output from a state in Step Functions is 32,768 characters (32KB).
3. Task State Input and Output Size:
   • For a Task state, the combined input and output size (including both input and result fields) must not exceed 32,768 characters.
4. Lambda State Input and Output Size:
   • When invoking an AWS Lambda function from a Step Function, the input and output to and from the Lambda function must not exceed 256KB.
5. Parameter Size in Map State:
   • When using a Map state, the combined size of parameters and results for each invocation must not exceed 32,768 characters.
6. Parameter Size in Parallel State:
   • When using a Parallel state, the combined size of parameters and results for each branch must not exceed 32,768 characters.
7. Size of Context Object in State Input and Output:
   • The entire context object passed between states (including state input and output) must not exceed 256KB.

Please note that these limits are based on information available up until September 2021. AWS may update these limits in the future, so it's always a good idea to refer to the latest AWS documentation for the most current information.

If you encounter situations where your Step Function input or output exceeds these limits, you may need to reevaluate your workflow design or consider using techniques like storing larger data in an external storage service (e.g., Amazon S3) and passing references or keys in your Step Function states.