Git flow -- how to update swagger.json files?

We’ve been using Postman for many years to test internal API’s and to help build integrations with external API’s. The internal endpoints have always been read from swagger.json which was created in the build process of a Web API (.NET Framework and .NET Core). We’re looking now to enhance the Postman environment with example requests and to make use of mocking, testing and monitoring. But the big issue is that each time an API is built the swagger.json file is a completely new file. How can the additional information added (via Postman or JSON modify) be carried forward when version changes have been made to the API? Some endpoints will simply carryover without change. How to re-append(?) metadata? Please let me know if this makes sense or if there’s something I’m missing.

It turns out we found a great solution. There are multiple options but a little SQL and C# goes a long way.