Why We Need Yet Another (OSS) Semantic Layer

Most semantic layers come with a great declarative modeling language to define metrics and measures well1, but very soon after, you start building wrappers around the semantic layer that enable agentic work and context engineering, that work well with harnesses and interfaces, and that allow flexible queries at runtime, without the need to rebuild or recalculate the measures in YAML. The other problem is that most data warehouse or analytics solutions basically lock you in with their…