gitlab-ce/app/serializers/pipeline_action_entity.rb

class PipelineActionEntity < Grape::Entity
  include RequestAwareEntity

  expose :name do |build|
    build.name.humanize
  end

  expose :url do |build|
    play_namespace_project_build_path(
      pipeline.project.namespace,
      pipeline.project,
      build)
  end
end