Custom Source


With Custom Source functionality, you can add your own integration to the File Picker based either on a static list of files or a dynamic integration of your choice. Below you can find API reference and you can check our tutorial to see how you can start with a simple example.

To integrate to source Filestack’s file picker, you must create an object that you can reference later in the File Picker configuration.

const customSource = {
  label: 'LABEL_IN_MENU',
  icon: 'ICON.svg',
  mounted: (element, actions) => {

  unmounted: (element) => {



  const apikey = YOUR_APIKEY;
  const client = filestack.init(apikey);
  const options = {
    fromSources: [ 'local_file_system', customSource, 'googledrive', 'unsplash', 'facebook', 'instagram']
    maxFiles: 20,
    uploadInBackground: false,
    onUploadDone: (res) => console.log(res),
  const picker = client.picker(options);;
label string Label displayed in the File Picker menu view
name string Unique key for source name, can`t contain spaces or special chars
icon string svg icon displayed in the File Picker menu view
mounted(element, actions) function method called after view is mounted (triggered when user clicks your Custom Source)
unmounted(element) function method called after view is unmounted

Mounted params

Method mounted is called with given params. Within method we should create our own custom HTML for our source, that will be visible for user, and add it to passed HTML element.

element HTMLElement that can be used to mount own view
actions.addRawFile(fileObj) Add raw file (FileObject or Blob) and goto summary view
actions.fetchAndAddUrl(url, headers) Try to fetch url metadata and add it to upload queue
actions.showSummaryView() After adding files you can show summary view to the user
actions.addCustomUrl(customFileObj) Add custom file object
actions.metadata(url, headers) Retrieve file metadata from url
actions.startUploading() Start file upload (not recommended, use showSummaryView instead)
actions.getFile(uuid) Returns file instance from list by uuid
actions.removeFile(uuid) removes file by uuid
actions.fileList Current file list for upload
actions.count Files count
actions.config Return config of the File Picker

Unmounted params

Unmounted method is called before custom source element will be removed. Within method we can ie. clear logged user session or remove unnecessary variables to release the browser memory.

element HTMLElement that can be used to mount own view

Mounted actions params


Add raw file object to the upload queue

rawFile required Raw File or Blob object with buffer


customFileObj required Custom file object:
    url: 'string' // url to upload
    type: 'string', // required - file mimetype
    filename: 'string', // required - original file name
    display_name: 'string', // optional - file display name in picker - if undefined filename will be taken
    thumbnail: 'string', // optional - thumbnail to display in picker
    headers: 'object' // optional - additional headers for request ie: 
    // headers: {
    //  'Authorization': `Bearer secret`,
    // },

fetchAndAddUrl(url, headers)

url required Url string to fetch
headers optional Additional headers to fetch file ie (Authorization)`
headers: {
  'string': `string`, // headerName: headerValue

metadata(url, headers)

We can call metadata action to retrieve information about url, that can be usefull before file upload. Action returns JSON object:

{ "filename": "someFile.jpg", // filename taken from url
  "display_name": "someFile", // displayed name fot the file - in most cases the same like filename
  "link_path": "", // full url of the file
  "thumbnail": "", // link for thumbnail if can be obtained
  "modified": "", // modified date if can be obtained from url
  "type": "text/html", // mimetype
  "size": 0 // filesize
url required URL string to fetch metadata
headers optional Additional headers to fetch file ie Authorization
headers: {
  'string': `string`, // headeName: headerValue


Returns file prepared for upload by uuid

  "url": "file url"
  "type": "file type"
  "filename": "file name"
  "display_name": "file display name"
  "thumbnail": "file thumbnail",
  "size": "file size",
  "headers": "additional headers",
  "uuid": "uuid v4"
uuid required File Unique id


Returns all files selected for upload


Returns selected for upload files count


Remove file from selected for uploads

uuid required File Unique id