Malformed action/metadata line [1], expected START_OBJECT but found [START_ARRAY]

[Hemabh_Ravee_Fox (Hemabh Ravee)]

I've been trying to use the bulk api to insert a large number of documents to an index.
I followed the documentation and came up with the following API call -

POST https://localhost:9200/index/_bulk
[
    {"create":{}},
    { "fileName": "filename1", "data":"massive string text data here" },
    {"create":{}},
    { "fileName": "filename2", "data":"massive string text data here" }
]

But I'm getting the following response -

{
    "error": {
        "root_cause": [
            {
                "type": "illegal_argument_exception",
                "reason": "Malformed action/metadata line [1], expected START_OBJECT but found [START_ARRAY]"
            }
        ],
        "type": "illegal_argument_exception",
        "reason": "Malformed action/metadata line [1], expected START_OBJECT but found [START_ARRAY]"
    },
    "status": 400
}

I can't seem to figure out what I'm doing wrong here.

[Christian_Dahlqvist]

Have a look at the docs around the bulk format. It is basically a set of lines, each holding a complete JSON object. You have array brackets at the start and end , which is incorrect. Have never used it through the Kibana dev console so am not sure if any special formatting is required.

[Hemabh_Ravee_Fox (Hemabh Ravee)]

I can't seem to find any documentation for generic api calls. Only for the language specific clients.

Bulk API | Elasticsearch Guide [8.4] | Elastic

This link is also showcasing using array brackets to combine the multiple documents that we want to create in Elasticsearch. Also, if I remove the array brackets, the content would no longer be a valid JSON.

[Christian_Dahlqvist]

There are no square brackets in any of the requests in those docs. This is what it is supposed to look like.

POST _bulk
{ "index" : { "_index" : "test", "_id" : "1" } }
{ "field1" : "value1" }
{ "delete" : { "_index" : "test", "_id" : "2" } }
{ "create" : { "_index" : "test", "_id" : "3" } }
{ "field1" : "value3" }
{ "update" : {"_id" : "1", "_index" : "test"} }
{ "doc" : {"field2" : "value2"} }

[Hemabh_Ravee_Fox (Hemabh Ravee)]

Okay so I just realised I was supposed to try this out from the kibana console. I was just making API calls using postman. This syntax worked from the kibana console. Thanks!

[Christian_Dahlqvist]

The same syntax applies if you send requests through Postman.