Error: Task Token is required in `payload` for callback. Use JsonPath.taskToken to set the token

Question

hi my state machine look like this

state_machine = sfn.StateMachine(
    self,
    "MyStateMachine",
    definition=tasks.LambdaInvoke(
        self,
        "MyLambdaTask",
        lambda_function=hello_function,
        integration_pattern=tasks.IntegrationPattern.WAIT_FOR_TASK_TOKEN,
        payload={   "payload.$": "$",
                    "execution_id.$": "$$.Execution.Id",
                    "taskToken.$": "$$.Task.Token"},
    ).next(
    self,
    "MyStateMachine_step2",
    definition=tasks.LambdaInvoke(
        self,
        "MyLambdaTask2",
        lambda_function=hello_function,
        integration_pattern=tasks.IntegrationPattern.WAIT_FOR_TASK_TOKEN,
        payload={   "payload.$": "$",
                    "execution_id.$": "$$.Execution.Id",
                    "taskToken.$": "$$.Task.Token"},
    )
        
        )
    )
)

on making build I am getting this error :

jsii.errors.JavaScriptError: Error: Task Token is required in payload for callback. Use JsonPath.taskToken to set the token. I even tried to put task token into payload but nothing is working till now

Answer 1

In payload you are defining

 "taskToken.$": "$$.Task.Token"},

How does your $$ look like ? Does it have a Task.Token ?

You can test it by adding a variable into payload something like (not sure about the dot after $$, just try it out :)

"everything.$": "$$."

And then in the step, check the value of "everything" and see if it has the Task.Token value.

$ = access to current step input json
$$ = access to initial stepfunction input json