Step Function — dynamodb query with Boolean Filter

I am a great fan of AWS step function.

One day, I had trouble querying dynamodb with boolean filter.

I found out that a slightly different syntax should be used in step function in querying with boolean filter.

This is the code that works.

{
   "TableName": "addresses",
   "ConsistentRead": true,
   "FilterExpression":"beingUsed = :beingUsed",
   "KeyConditionExpression": "#type = :EOA",
   "ProjectionExpression": "#address, beingUsed",
   "ExpressionAttributeNames": {
     "#address": "address",
     "#type": "type"
   },
   "ExpressionAttributeValues": {
     ":EOA": {
       "S":"EOA"
     },
   ":beingUsed":{
     "Bool":false 
   }
 }
}

In the ExpressionAttributeValues, it is neither

":beingUsed":false

nor

":beingUsed":{
  "BOOL":false
}

It should be

":beingUsed":{
  "Bool":false
}

I hope this one save someone’s time.

Thank you.