DL-202
Multi-provider addressing is an optional ForgeRef forge field on the ForgeCallRequest envelope (unset = the configured default GitHub forge — the additive follow-up the standing agent_gateway.proto comment names); there is no capability-negotiation RPC: an op the addressed provider cannot serve returns the in-band ForgeCallError{code:"unimplemented"} built on forge.ErrUnsupported, and the agent tool prompt documents the static per-provider capability matrix
Status: Active (Matt, 2026-08-17)