AWS Step Functions with JSONata query language supports passing a JSONata expression as the entire Payload value in a Lambda invoke task (docs):

The Arguments and Output fields (and other similar fields) will accept either a JSON object or a JSONata expression directly.

However, LambdaInvokeArgs.payload is typed as Record<string, Input<unknown>>, which only accepts objects. This forces a @ts-expect-error workaround:

const task = sst.aws.StepFunctions.lambdaInvoke({
  name: "FetchBatch",
  function: myFn,
  // @ts-expect-error: payload should accept JSONata expressions
  payload: "{% $states.input %}",
});

StateArgs.output already handles this correctly:

// state.ts
output?: Input<JSONata | Record<string, any>>;

Suggested fix: #6583

In platform/src/components/aws/step-functions/task.ts, change:

payload?: Record<string, Input<unknown>>;

to:

payload?: Input<JSONata | Record<string, Input<unknown>>>;