Microsoft's open trust stack runs on OpenInference

Microsoft announced ASSERT (a spec-driven evaluation framework) and Agent Control Specification (ACS) for runtime controls, both built on OpenInference, Arize’s OpenTelemetry-based standard for AI observability. The shared telemetry layer connects evaluation, policy enforcement, and production observability through a unified trace contract, enabling developers to test, secure, and monitor agents across any framework without vendor lock-in. Jim Bennett, Principal Developer Experience Engineer, explains how this creates an open trust stack where OpenInference serves as the common language across the entire agent lifecycle.