This is the Go client library for Prometheus. It has two separate parts, one for instrumenting application code, and one for creating clients that talk to the Prometheus HTTP API.

This library requires Go1.9 or later.

In this repository, we used to mostly ignore the many coming and going dependency management tools for Go and instead wait for a tool that most of the community would converge on. Our bet is that this tool has arrived now in the form of Go Modules.

To make full use of what Go Modules are offering, the previous versioning roadmap for this repository had to be changed. In particular, Go Modules finally provide a way for incompatible versions of the same package to coexist in the same binary. For that, however, the versions must be tagged with different major versions of 1 or greater (following Semantic Versioning). Thus, we decided to abandon the original plan of introducing a lot of breaking changes before releasing v1 of this repository, mostly driven by the widespread use this repository already has and the relatively stable state it is in.

To leverage the mechanism Go Modules offers for a transition between major version, the current plan is the following:

• The v0.9.x series of releases will see a small number of bugfix releases to deal with a few remaining minor issues (#543, #542, #539).
• After that, all features currently marked as deprecated will be removed, and the result will be released as v1.0.0.
• The planned breaking changes previously gathered as part of the v0.10 milestone will now go into the v2 milestone. The v2 development happens in a separate branch for the time being. v2 releases off that branch will happen once sufficient stability is reached. v1 and v2 will coexist for a while to enable a convenient transition.
• The API client in prometheus/client_golang/api/… is still considered experimental. While it will be tagged alongside the rest of the code according to the plan above, we cannot strictly guarantee semver semantics for it.

The prometheus directory contains the instrumentation library. See the guide on the Prometheus website to learn more about instrumenting applications.

The examples directory contains simple examples of instrumented code.

The api/prometheus directory contains the client for the Prometheus HTTP API. It allows you to write Go applications that query time series data from a Prometheus server. It is still in alpha stage.

The model packages has been moved to prometheus/common/model.

The extraction and text packages are now contained in prometheus/common/expfmt.

See the contributing guidelines and the Community section of the homepage.