Agents can hold wallets, execute payments, and submit documents - they just can't prove who they are. W3C DIDs and Verifiable Credentials fill the gap. The window to build this layer openly, before platform-specific alternatives calcify, is now.
Published agentic AI stack architectures — five-layer, seven-layer, and nine-layer frameworks in common circulation, alongside Microsoft's own agentic AI roadmap reviewed as of April 2026 — cover compute, models, orchestration, tooling, and observability. None include trust as a named layer. Agents can hold wallets, execute payments, and submit documents - they just can't prove who they are. This paper examines why the identity layer is missing from agent runtimes, how existing standards (W3C DIDs, Verifiable Credentials) can fill the gap, and why the window to build it openly is now.