anchor.diff:  
   ## Developing a plugin
   
  -The best place to get started is the [Buildkite Plugins] repository, or [third-party plugins with the `buildkite-agent` tag](third party plugins).
  +The best place to get started is the [Buildkite Plugins] repository, or [third-party plugins with the `buildkite-agent` tag][third party plugins].
   
   We mostly write our plugins as shell scripts, so we've created a [plugin tester] 
   docker image that simplifies writing BATS tests and getting your plugin tested (so meta).
  
positive.code: 
   * Apply special care in plugins to avoid executing arbitrary code passed in by config. As these are just environment variables, anything that can set environment variables can mess with plugin configuration.
  
  For particularly high-security setups, you can disable plugins selectively by removing them from the `BUILDKITE_PLUGINS` variable in your `environment` hook, or preventing them from being loaded entirely with the `no-plugins` [agent configuration]() parameter.
  
  ## We love feedback!
  
  Agent plugins are still a new thing and we are evolving them as we learn more. We'd love feedback on how you use them and how we might make them better.
  
  [hooks]: https://buildkite.com/docs/agent/hooks
  [standard environment variables]: https://buildkite.com/docs/builds/environment-variables#provided-by-buildkite
  [Unofficial Bash Strict Mode]: http://redsymbol.net/articles/unofficial-bash-strict-mode/
  [shellcheck]: https://github.com/koalaman/shellcheck
  [docker plugin]: https://github.com/buildkite-plugins/docker-buildkite-plugin
  [docker-compose plugin]: https://github.com/buildkite-plugins/docker-compose-buildkite-plugin
  [Buildkite Plugins]: https://github.com/buildkite-plugins
  [third party plugins]: https://github.com/search?q=topic%3Abuildkite-plugin&type=Repositories
  [plugin tester]: https://github.com/buildkite-plugins/plugin-tester
  
negative.code: __Plugins are only available in the beta 3.0 version of the agent__
  
  Plugins provide a way to extend the functionality that Buildkite natively offers. 
  Essentially, they are  collections of [Hooks][hooks] that run as part of your 
  builds. They can be hosted on GitHub, BitBucket or a private git repository and 
  are automatically fetched as required. 
  
  Buildkite offers a [collection of useful plugins][Buildkite Plugins]
  to get you started, including a [docker-compose plugin] and a plugin for [secure 
  secrets storage][s3-secrets plugin] on Amazon S3.
  
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