Is there such a thing as an embeddable integration engine?

Our business, like many others, is in an industry where our customers need us to integrate with other platforms that are very industry-specific.

The workflow is fairly standard. Based on an event occurring in our platform we need to make a call to an external API. Credentials are specific to the customer. And many times we need to pull data from the external API and provide a way to make custom mappings between our attributes and the customer's attributes in the external system.

There's lots of platforms that sort of do this (Zapier), but what I want is a platform or engine I can embed in ours that handles the generic idea of sourcing events from our system, making custom mappings/transforms, and connecting them to whatever integrations we build. It would need to be a very easy to use drag-and-drop UI for non-technical users. Essentially I want something like idea of a Zapier as a framework that handles the orchestration in a generic way and allows us to build whatever integrations we need.

I know there's BPMN systems and workflow systems, but they all seem to be tailored towards a specific business rather than a platform where multiple businesses would be operating with their own particular integrations and use cases.

I know this is a common, recurring problem in pretty much every industry, so the question is: does this exist? I'd really rather not build something if it's already available.