Is it possible to search for envelopes created by a specific integration/app?

Consider a scenario where a DocuSign account has 3 independent applications accessing it ...

• Application A creates envelopes and downloads the documents from the envelopes it created when they are completed.
• Application B creates envelopes.
• Application C downloads those envelopes created by Application B once the are completed.

Is there a way for Application C to find envelopes that were created by Application B without knowing the IDs of those envelopes or custom field values / sender identity etc? Ideally I'd like to be able to find envelopes by searching for the integration key that Application B uses.

You cannot do this unless application B uses some sort of unique meta-data like custom fields or some other way to "mark" its envelopes. This information can be found internally by DocuSign running some tools/reports, but for others to know this - you have to provide your own meta-data that can be searched upon.