Client libraries

Before you can monitor your services, you need to add instrumentation to theircode via one of the Prometheus client libraries. These implement the Prometheusmetric types.

Choose a Prometheus client library that matches the language in which yourapplication is written. This lets you define and expose internal metrics via anHTTP endpoint on your application’s instance:

• Go
• Java or Scala
• Python

• RubyUnofficial third-party client libraries:

• Bash

• C++
• Common Lisp
• Elixir
• Erlang
• Haskell
• Lua for Nginx
• Lua for Tarantool
• .NET / C#
• Node.js
• Perl
• PHP
• RustWhen Prometheus scrapes your instance's HTTP endpoint, the client librarysends the current state of all tracked metrics to the server.

If no client library is available for your language, or you want to avoiddependencies, you may also implement one of the supported expositionformats yourself to expose metrics.

When implementing a new Prometheus client library, please follow theguidelines on writing client libraries.Note that this document is still a work in progress. Please also considerconsulting the development mailing list.We are happy to give advice on how to make your library as useful andconsistent as possible.