Hi,
please provide the docs and ideas about this.
Scenario: a) subscribe the user
. b) use the services.
can we have any opensource to implement this (developer portal) and can we integrate with APIGEE.
Yes, you can use Apigee Trail to create proxies and publish them using Integrated Dev Portal. It can be used for testing purposes and not suited for Production.
https://docs.apigee.com/api-platform/get-started/get-started