OpenTelemetry Semantic Conventions

Semantic conventions define standardized names, types, and semantics for telemetry attributes, span names, metric instruments, and log fields. They ensure that telemetry from different libraries, frameworks, and services describes the same concepts in the same way — enabling correlation, querying, and tooling across the entire stack.

The Attribute Registry is the single source of truth for all defined attributes.

Rules

Official documentation

• Attribute Registry
• Semantic Conventions Specification
• Semantic Conventions Repository
• Dash0 Semantic Conventions
• Dash0 Semantic Conventions Explainer

Key principles

• Registry first — Search the Attribute Registry before creating any custom attribute
• No custom attributes unless necessary — Custom names fragment querying and break tooling
• Low cardinality in names — Span names and metric attribute values must be bounded; variable data goes in attributes
• Right level, every time — Place attributes at the correct telemetry level (resource, scope, span, log, metric)
• Consistent placement — Once an attribute is at a level, keep it there across all services

Quick reference