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+# Prometheus integration
+
+This integration exposes metrics in a Prometheus compatible format.
+
+## Metric naming guidelines
+
+Please follow these guidelines while defining metrics.
+
+* Metric and label names should conform to [Prometheus
+  naming guidelines](https://prometheus.io/docs/practices/naming/).
+* Domain-specific metrics should have the domain (`sensor`, `switch`,
+  `climate`, etc.) as a metric name prefix.
+* Enum-like values (e.g. entity state or current mode) should be exported using
+  a "boolean" metric (values of 0 or 1) broken down by state/mode (as a metric
+  label).