ARC-1 behind the SAP Integration Suite MCP Gateway (MCP Federation)

[ClementRingot]

Context
We run ARC-1 on BTP Cloud Foundry with XSUAA + principal propagation (read-only + SQL read for now). The MCP Gateway in Integration Suite is now GA, but its documented sources (API artifact, HTTP endpoint with OpenAPI, RFC backend) are all API-to-MCP wrapping. SAP's July 2026 Integration Suite update lists "MCP Federation" — bringing third-party MCP servers under the Gateway control plane — as a roadmap item.

Questions

1. Is MCP-to-MCP federation behind the Gateway something ARC-1 plans to support once SAP ships it? Any known timeline?
2. Identity: the Gateway validates OIDC tokens via SAP Cloud Identity Services. What would be the expected token flow so ARC-1 still does per-user principal propagation (IAS → XSUAA exchange, ARC-1 trusting IAS directly, something else)? Would ARC-1's own OAuth / stateless DCR layer be bypassed in that topology?
3. Is there any reasonable interim pattern (e.g. an OpenAPI façade registered as an HTTP endpoint source), or does that lose too much of ARC-1's tool semantics to be worth it?
4. Policy angle: the docs note that a Gateway in front would not by itself settle API Policy §2.2.2 for ADT endpoints. Do you still see federation as strengthening the "SAP-endorsed architecture" argument?

Happy to help test once there's something to test.

[marianfoo]

Hi @ClementRingot
yes, i am following this and in my point of view this is not usable right now with ARC-1.
I did not look closer until the feature to use MCP Server over the Gateway with PP is GA, which i think is not?
If you dont use the Gateway for anyhting else, why make it more complicated?
ARC-1 has PP, Rate Limiting, Logging, so all the important parts that a Gateway provides.
If you happy with your current setup, stick to it.
I will continue to look how SAP is evolving and test what i can support