AWS Step Functions Not Transitioning States Correctly with Dynamic Input Path
Quick question that's been bugging me - I'm working with an scenario with my AWS Step Functions state machine where the transitions between states are not happening as expected. I've defined a state machine that should process multiple Lambda functions in sequence, passing dynamic input between them. However, I'm observing that the input is not being correctly set for the next state, which leads to `Invalid Input` errors in the subsequent Lambda functions. Here’s the relevant part of my state machine definition: ```json { "Comment": "A simple AWS Step Functions state machine that invokes two Lambda functions", "StartAt": "FirstLambda", "States": { "FirstLambda": { "Type": "Task", "Resource": "arn:aws:lambda:us-east-1:123456789012:function:FirstLambda", "ResultPath": "$.firstResult", "Next": "SecondLambda" }, "SecondLambda": { "Type": "Task", "Resource": "arn:aws:lambda:us-east-1:123456789012:function:SecondLambda", "InputPath": "$.firstResult", "ResultPath": "$.secondResult", "End": true } } } ``` In this configuration, I want the output of `FirstLambda` to be passed directly to `SecondLambda`, but instead, I keep getting an behavior: `behavior: Input does not match expected format` when executing the Step Function. I've checked the output from `FirstLambda`, and it seems to be in the correct format, so I'm not sure what’s going wrong. As a troubleshooting step, I've added logging to both Lambda functions to confirm their outputs: ```javascript // FirstLambda.js exports.handler = async (event) => { console.log('FirstLambda input:', event); return { success: true, data: "This is the output" }; }; ``` ```javascript // SecondLambda.js exports.handler = async (event) => { console.log('SecondLambda input:', event); }; ``` From the logs, it appears that `FirstLambda` is returning `{ success: true, data: "This is the output" }`, but `SecondLambda` is receiving `undefined` or an unexpected structure. I've tried modifying the `InputPath` in `SecondLambda` to various configurations, such as `InputPath: "$.firstResult.data"`, but that leads to further errors. I’m unsure how to properly configure the input path so that the expected output from `FirstLambda` is correctly passed to `SecondLambda`. Any insights on how to resolve this would be greatly appreciated! This is part of a larger service I'm building. Has anyone else encountered this? What's the best practice here?