Hi , I am new to keto and was trying to explore the same and implement the same for POC Just wanted to check how's OPL config is different from the relationship or permission API. Can someone point me to documentation, not sure if I am missing something. But as per my understanding namespace and relationship can be created both using OPL config and API .

Your understanding is correct, however, creating namespaces through OPL is currently significantly less bothersome than doing it through the API, although this will be addressed soon™. There are some obvious pros and cons to using either. OPL supports some really fine grained ways to check permissions, while the API will obviously allow you to make more dynamic changes on the fly, programmatically. For some OPL examples - I'm sure you have already seen this - you can check out the docs: https://www.ory.sh/docs/guides/permissions/overview

Thanks a lot for your input, will DM you with my use case and understanding