OpenMetrics

OpenMetrics is an open standard for exposing metrics data in distributed systems. It provides a vendor-neutral, machine-readable format intended to improve interoperability among monitoring systems, data analysis tools, and instrumented applications. The specification covers both a text-based exposition format and a JSON representation, designed to be human-readable while supporting automated parsing at scale.

Key features include a formalized notion of metric families, individual samples with labels, and data types such as counter, gauge, histogram, and summary. The format supports optional unit annotations and rich metadata describing metrics, their descriptions, and the meaning of labels. By codifying how metrics are named, labeled, and serialized, OpenMetrics aims to reduce discrepancies between exporters and consumers and to enable more consistent scraping, querying, alerting, and storage.

OpenMetrics is associated with the broader cloud-native observability ecosystem and is compatible with, and widely adopted by, tools in the Prometheus ecosystem. It seeks to standardize not only how metrics are emitted but also how they are discovered and interpreted across different platforms. The project is maintained by an open community under the auspices of organizations contributing to cloud-native monitoring and observability, with ongoing improvements to the specification and reference implementations.

See also: Prometheus exposition format, OpenTelemetry, CNCF.