The OpenTelemetry project consists of multiple components. These components are made available as a single implementation to ease adoption and ensure a vendor-agnostic solution. More components may be added in the future.


Language independent interface types. Defined per data source for instrumentation libraries and the collector as well as for common aspects and resources. Proto files are extensively commented. For more information, see the proto repository.


Describes the cross-language requirements and expectations for all implementations. Beyond definition of terms, the specification defines the following:

  • API: Used to generate telemetry data. Defined per data source as well as for other aspects including baggage and propagators.
  • SDK: Implementation of the API with processing and exporting capabilities. Defined per data source as well as for other aspects including resources and configuration.
  • Data: Defines semantic conventions to provide vendor-agnostic implementations as well as the OpenTelemetry protocol (OTLP).

For more information, see the specification repository.


The OpenTelemetry Collector offers a vendor-agnostic implementation on how to receive, process, and export telemetry data. It removes the need to run, operate, and maintain multiple agents/collectors in order to support open-source observability data formats (e.g. Jaeger, Prometheus, etc.) sending to one or more open-source or commercial back-ends. The Collector is the default location instrumentation libraries export their telemetry data.

For more information, see the Data Collection section.

Instrumentation Libraries

The inspiration of the OpenTelemetry project is to make every library and application observable out of the box by having them call the OpenTelemetry API directly. Until that happens, there is a need for a separate library which can inject this information. A library that enables observability for another library is called an instrumentation library. The OpenTelemetry project provides an instrumentation library for multiple languages. All instrumentation libraries support manual (code modified) instrumentation and several support automatic (byte-code) instrumentation.

For more information, see Instrumenting section.

Last modified February 15, 2021: Cleanup the component docs (#378) (16aff06)