I am Antonin, the co-chair of the P4 API Working Group. We maintain and evolve the P4Runtime API specification. We meet once a month to discuss open issues and new proposals. Everyone is welcome to join!
Feel free to ask any question you may have about the P4Runtime API here. We are happy to provide clarifications to the specification, provide implementation advice (server or client), discuss new ideas, etc.
For up-to-date information about the P4 API Working Group, including the meeting calendar, refer to Working Groups « P4 – Language Consortium