Best way to transfer files to Appian from a External system

I believe either or should be fine, We have used a mixture of both, where we transfer files out of Appian using SFTP, then bring documents back to Appian not necessarily using (AWS), our files are stored locally, but using the same approach where we send the uploaded fileid + metadata as API input.

Hi Sricharan,

We had same scenario earlier so we have used the 1st option which is very straight forward and can send 'n' number of files easily.

We have used SFTP for transferring the files from Appian to external system. That's a very commonly used approach.
In case the file is prepared and transferred to external system, outside the scope of the Appian process, we had a webservice which Appian called. The webservice took care of preparing the document and transferring it.

Two more options as follows -

1) HTTP File Download Smart Service - An option to download documents from an external system using REST APIs

For more information on smart service configuration, view documentation at
docs.appian.com/.../HTTP_File_Download_Smart_Service.html

2) Base64 Document Database Integration Smart Service - You can get Base64 documents from a database into Appian, if external system has saved documents in database in Base64 string format. Smart service automatically coverts Base64 string into an Appian Document.

Smart service is available on AppMarket at
community.appian.com/.../base64-document-database-integration

I suggest testing out these plug-ins available in AppMarket per your requirements before using it for production as they are not kept up-to-date per latest Appian version.