How can I merge two PDF files?

[cloudyrobert]

tl;dr I need to take a PDF file attached by a user and programmatically add a page to it that contains information from ServiceNow.

I'm setting up a system to allow users to submit invoices through ServiceNow. The invoices will go through a review and approval process before being sent by email to an external system for payment. The external system and associated processes are not very flexible and require that there be a single attachment that includes the invoice itself as well as key details about the approvals given, etc.

Using the information in this post, I've been able to generate a PDF file with custom content. I am having no luck figuring out a way to either a) add content to an existing file or b) merge two files.

I am not trying to populate a signature or other pre-defined fields in a template. I could do this for the fields that are predictable, but I would still need to merge it with the invoice, which is different every time.

[mintacliett]

could you add the two files to a separate table using import sets/transform maps and then export all of that data into one pdf? You may have to do a scheduled job to pick up on the users attachments...

[cloudyrobert]

Minta! It's been a long time--hope you're doing well. I don't know of a way to do that and preserve the original PDF file exactly as it was. Do you have any ideas for that?

[cloudyrobert]

Based on feedback from HI and Joe's post on this community thread, I'm thinking this isn't currently possible.