Metrics SQL by Rill
One SQL semantic layer so AI agents stop hallucinating your KPIs
Metrics SQL is a SQL-based semantic layer from Rill Data that solves a specific and painful problem: AI agents that query your data warehouse tend to hallucinate aggregation logic, producing metrics that look plausible but are mathematically wrong. Metrics SQL lets analysts define business metrics once — revenue, MAU, conversion rate, ROAS — in a governed definition layer, and then exposes those definitions as queryable SQL tables. Every dashboard, notebook, and AI agent resolves from the same source. The technical approach is elegant: rather than inventing a new DSL, Metrics SQL extends SQL itself. An agent that knows SQL can query `SELECT * FROM metrics.weekly_revenue` and get correctly computed numbers without needing to know how revenue is defined, which tables it joins, or how edge cases like refunds are handled. The semantic layer intercepts the query, applies the governed definition, and returns correct results. The implications for AI-native data stacks are significant. Currently, one of the biggest failure modes for AI analysts and BI agents is inconsistent metric computation — different agents or dashboards produce different numbers for 'revenue' because they implement aggregation logic differently. Metrics SQL addresses this at the infrastructure level, not by improving agent prompting.
Panel Reviews
The Builder
Developer Perspective
“We've been burned by data agents that invent their own GROUP BY logic and produce wrong numbers that look right. Metrics SQL solves this at the infrastructure level — define revenue once, have every agent query the same definition. The SQL-native interface means no new tools for agents to learn; they just use the tables.”
The Skeptic
Reality Check
“The value here is only as good as how well-maintained your metric definitions are — if analysts don't keep them updated, agents query stale or wrong definitions and you've added a layer of false confidence. Adopting a semantic layer also creates vendor dependency; migrating away from Rill's cloud later is a real switching cost. For smaller teams without dedicated data engineering, maintaining a semantic layer is overhead.”
The Futurist
Big Picture
“Data governance and AI agents are on a collision course. As more business decisions are delegated to AI, the correctness of KPI computation becomes load-bearing — a hallucinated revenue figure that influences a product decision is a serious failure mode. Metrics SQL represents a class of infrastructure that will become mandatory as AI takes on more analytical work.”
The Creator
Content & Design
“I rely on AI to pull weekly performance data, and the number of times it's given me different 'correct' answers for the same metric is maddening. Having a single governed source that every AI query resolves against means I can trust the numbers I'm making decisions on. That trust is worth a lot.”
Community Sentiment
“Hallucinated GROUP BY logic as the problem being solved”
“Comparison to dbt metrics layer approach”
“AI data agents producing inconsistent numbers”