How to receive response, that is blob object, with kintone.proxy?

I downloaded icon on a domain of kintone with kintone.proxy. The response is in text format. I want to receive a blob object. Which way can i do to receive desire result?


Hello Tan,

As Chris mentioned in the other post,

could you try and see by writing,

const data = { format: "RAW", value: new Blob([arrayBuffer]) };

resolves the issue you are having?
Hopefully, this helps.


Thanks Sean,

Maybe my description is not clear. My problem: I am standing at domain A of kintone, download icon file(png) at domain B of kintone by kintone.proxy . Then I upload this content of file to current domain (domain A), and then I attempt filekey of the file to general setting, kintone informate for me: the file is not png, jpeg… format. What can I do in this case to resolve this problem?

download file code:

    get_file_dev(filekey, api_url='k/v1/file.json') {

      let url = this.dev_domain + api_url + `?fileKey=${filekey}`

        return kintone.proxy(url, 'GET', header_dev, {}).then(resp => {

            return resp[0]

        }, error => {

            throw `${error.message}get file key ${filekey} fail`



Upload file code:  (data = resp[0])

  upload_file_product(data, object_data, api_url='k/v1/file.json') {

        return new Promise(function (resolve, reject) {

            let blob = new Blob([data], {type: object_data['contentType']});

            let formData = new FormData();

            formData.append(' __REQUEST_TOKEN__', kintone.getRequestToken());

            formData.append('file', blob, object_data['name']);

            let url = kintone.api.url(`/${api_url}`);

            let xhr = new XMLHttpRequest();

  'POST', url);

            xhr.setRequestHeader('X-Requested-With', 'XMLHttpRequest');

            xhr.onload = function() {

            if (xhr.status === 200) {

                // success



            } else {


                throw `${JSON.parse(xhr.responseText)}upload file ${object_data['name']} fail`







Thank your support


Hi Tan,

Thank you for your reply.

In the kintone.proxy function, only strings are supported as the response body returned by the proxy destination.
In other words, binary data such as images cannot be retrieved.

However, if you use the kintone.proxy.upload function, which uploads files to an external location, can execute file upload API.

After downloading the file using XMLHttpRequest on domain B, execute the file upload API on domain B using the kintone.proxy.upload function on domain A.

Hopefully, this helps.

Hi Sean

Thank you for your support,

I must stand at domain A to download icon at domain B. So I can’t use XMLHttpRequest to download icon at domain B.

Thank you so much. You are kind