$0 Orders via API

I can successfully create an order via the API for a $0 purchase, however the contact doesn’t get added to a campaign funnel for that purchase unless we manually add a $0 payment in the Infusionsoft user interface.

I’ve attempted to add a $0 payment via the API to solve this, but the API errors and says “Invalid Payment Amount”. The payment amount property is apparently optional, but omitting it leads to the same error.

We can not get a contact added to a campaign pipeline for $0 orders via the API alone.

Help!

I would open an API support ticket for this. This sounds like a bug.