Question: Before sending the data I am using JSON.stringify to the data and it looks like this

```
{"data": [{"key1": value1, "key2": value2}, {"key1": value1, "key2": value2}]}

```

But once it passes through AWS API Gateway and Kinesis Firehose puts it to S3 it looks like this

```
    {
     "key1": value1, 
     "key2": value2
    }{
     "key1": value1, 
     "key2": value2
    }

```

The seperator comma between the JSON objects are gone but I need it to process data properly.

Template in the API Gateway:

```
#set($root = $input.path('$'))
{
    "DeliveryStreamName": "some-delivery-stream",
    "Records": [
#foreach($r in $root.data)
#set($data = "{
    ""key1"": ""$r.value1"",
    ""key2"": ""$r.value2""
}")
    {
        "Data": "$util.base64Encode($data)"
    }#if($foreach.hasNext),#end
#end
    ]
}

```

Answer: 
I had this same problem recently, and the only answers I was able to find were basically just to add line breaks ("\n") to the end of every JSON message whenever you posted them to the Kinesis stream, or to use a raw JSON decoder method of some sort that can process concatenated JSON objects without delimiters.

I posted a python code solution which can be found over here on a related Stack Overflow post:
<https://stackoverflow.com/a/49417680/1546785>
Once AWS Firehose dumps the JSON objects to s3, it's perfectly possible to read the individual JSON objects from the files.

Using **Python** you can use the `raw_decode` function from the `json` package

```
from json import JSONDecoder, JSONDecodeError
import re
import json
import boto3

NOT_WHITESPACE = re.compile(r'[^\s]')

def decode_stacked(document, pos=0, decoder=JSONDecoder()):
    while True:
        match = NOT_WHITESPACE.search(document, pos)
        if not match:
            return
        pos = match.start()

        try:
            obj, pos = decoder.raw_decode(document, pos)
        except JSONDecodeError:
            # do something sensible if there's some error
            raise
        yield obj

s3 = boto3.resource('s3')

obj = s3.Object("my-bukcet", "my-firehose-json-key.json")
file_content = obj.get()['Body'].read()
for obj in decode_stacked(file_content):
    print(json.dumps(obj))
    #  { "key1":value1,"key2":value2}
    #  { "key1":value1,"key2":value2}

```

source: <https://stackoverflow.com/a/50384432/1771155>

Using **Glue / Pyspark** you can use

```
import json

rdd = sc.textFile("s3a://my-bucket/my-firehose-file-containing-json-objects")
df = rdd.map(lambda x: json.loads(x)).toDF()
df.show()

```

source: <https://stackoverflow.com/a/62984450/1771155>