AWS Step functions Api Gateway integration RequestBody.$ bug

I have a state machine splitted in some different lambdas to complete a process. One of the steps is a call to apigateway lambda function. Previous call is a call to lambda function and in ASL language I tell to pass the object overrided by this function to the next step.

When it comes to Apigateway step, PathParameters are filled ok with the jsonpath accessors but when I try to use in RequestBody the received value are always empty.

I'm using golang language

State Machine
"UploadFile": {
"Type": "Task",
"Resource": "${UploadFileFunctionArn}",
"Retry": [
{
"ErrorEquals": [
"States.TaskFailed"
],
"IntervalSeconds": 2,
"MaxAttempts": 3,
"BackoffRate": 2.0
}
],
"Catch": [
{
"ErrorEquals": [
"States.ALL"
],
"ResultPath": null,
"Next": "Fail"
}
],
"ResultPath": "$",
"Next": "UpdateTerminal"
},
"UpdateTerminal": {
"Type": "Task",
"Next": "HasBeenUpdated",
"Resource": "${UpdateTerminalFunctionArn}",
"Parameters": {
"ApiEndpoint": "${APIDomainName}/${APIBasePath}",
"Method": "POST",
"Stage": "${ApiStageName}",
"Path": "",
"PathParameters": {
"terminalId.$": "$.terminalId"
},
"RequestBody.$": "$",
"AuthType": "NO_AUTH"
},
"Retry": [
{
"ErrorEquals": [
"States.TaskFailed"
],
"IntervalSeconds": 2,
"MaxAttempts": 3,
"BackoffRate": 2.0
}
]
},

Update terminal lambda logs :

fmt.Println("request.Body", request.Body)
fmt.Println("request.PathParameters['terminalId']", request.PathParameters["terminalId"])

2020-12-07T13:55:23.889+01:00	request.Body  
2020-12-07T13:55:23.889+01:00	request.PathParameters\['terminalId'] dc725a3a-0b96-4b14-8036-5c36514466556  

Edited by: eguzkilorebeltza on Dec 7, 2020 5:08 AM