Waxell vs. Braintrust: When Evaluation Isn't Enough

Braintrust is a developer-centric evaluation platform for scoring AI agent outputs, tuning prompts, and tracking quality regressions, but it only addresses output quality—not runtime governance. Waxell serves as a runtime governance control plane that enforces policies, controls tool access, and produces compliance audit trails for agents in production. The article argues that evaluation and governance answer fundamentally different questions, and teams need both to safely run AI agents in production.