Web API to receive a document from an external system

Question

Hi, 
 Is it possible to create a WebAPI in Appian that can receive a document? 
 Basically an API that can handle multipart requests. 
 
 Regards, 
 Sunil Zacharia

aloks0189 · Answer

Hi couple of things here: 
 
1. Integration Object is Only meant for Querying / Pushing the data from/to a Service in the Text Format. And also an external System cannot execute an Integration Object directly, instead they can only interact to Appian Web-API. 
 
2. Dealing with Base64 will slow down your entire environment, because when you perform Base64 conversion, then the document converted size will be much bigger than the actual. Also we never know about the user, what size of document he may to upload. Hence we need Binary Streaming, because Binary Stream reads as well as writes the data simultaneously instead of holding the entire content in memory as Base64 processing. 
 
3. Now coming to your problem statement, In order to push a document into Appian from an external system, external system need to send a POST request to Appian Web API, where the body should contain the document Download URL of external System, this POST Call will trigger a process in Appian where Appian will pass this Document URL as an input to the target process model as a parameter. Where we need to make the use of HTTP File Download Smart Service to authenticate the endpoint and download the document into Appian and store it under Knowledge Center.

I agree, we cannot call it as actual Upload mechanism, but as of now, this is the only way for an external system to push a document into Appian with respect to the performance. 
 
Hope this helps.