Highlights of the Fillable API 

• Design fillable forms: Create fillable forms from scratch and add various types of fields—such as text boxes, radio buttons, and checkboxes—in your app to collect business data from your users.
  
• Repurpose existing documents to interactive forms: Open PDF, TXT, or RTF files from your local drive or a publicly accessible URL and turn them into interactive fillable forms by adding fillable, signature, and various other types of fields as required.
  
• Collaborate on designing customized fillable documents: You can share fillable forms with your colleagues and collaborate on their design to customize the fillable forms.
  
• Prefill form values: Automatically prefill certain fields in the fillable form, such as the user's name and address, before sharing it with your users.
  
• Collect and save business data: Simply share a URL with your users to access and complete your customized fillable forms. You can then store the collected data in any location of your choice.
  
• Flexible post-completion actions: You can also specify the redirection URL and display message after a user submits the form.

Using the Fillable APIs

• Unique API key to identify your web app.
  
• Business form's storage location, or its URL.
  
• Data to be prefilled.
  
• Location to store the submitted responses and its file format.
  
• Redirection URL and display message after form submission.