Building Dbt Semantic Layer

---
name: building-dbt-semantic-layer
description: Use when creating or modifying dbt Semantic Layer components — semantic models, metrics, dimensions, entities, measures, or time spines. Covers MetricFlow configuration, metric types (simple, derived, cumulative, ratio, conversion), and validation for both latest and legacy YAML specs.
user-invocable: false
metadata:
  author: dbt-labs
---

# Building the dbt Semantic Layer

This skill guides the creation and modification of dbt Semantic Layer components: semantic models, entities, dimensions, and metrics.

- **Semantic models** - Metadata configurations that define how dbt models map to business concepts
- **Entities** - Keys that identify the grain of your data and enable joins between semantic models
- **Dimensions** - Attributes used to filter or group metrics (categorical or time-based)
- **Metrics** - Business calculations defined on top of semantic models (e.g., revenue, order count)

## Additional Resources

- [Time Spine Setup](references/time-spine.md) - Required for time-based metrics and aggregations
- [Best Practices](references/best-practices.md) - Design patterns and recommendations for semantic models and metrics
- [Latest Spec Authoring Guide](references/latest-spec.md) - Full YAML reference for dbt Core 1.12+ and Fusion
- [Legacy Spec Authoring Guide](references/legacy-spec.md) - Full YAML reference for dbt Core 1.6-1.11

## Determine Which Spec to Use