eval.rb

# frozen_string_literal: true

# Braintrust Rails Engine — mount example
#
# This file shows one conventional setup for the Braintrust eval server in Rails:
#   1. Define evaluator classes under app/evaluators/
#   2. Generate the initializer with:
#        bin/rails generate braintrust:server
#   3. Mount the engine in config/routes.rb
#
# Requirements:
#   gem 'actionpack', '~> 8.0'
#   gem 'railties', '~> 8.0'
#   gem 'activesupport', '~> 8.0'

# ---------------------------------------------------------------------------
# app/evaluators/my_classifier.rb
# ---------------------------------------------------------------------------

class MyClassifier < Braintrust::Eval::Evaluator
  def task
    ->(input:) { classify(input) }
  end

  def scorers
    [Braintrust::Scorer.new("accuracy") { |expected:, output:| (output == expected) ? 1.0 : 0.0 }]
  end
end

# ---------------------------------------------------------------------------
# config/initializers/braintrust_server.rb
# ---------------------------------------------------------------------------

# Generated by: bin/rails generate braintrust:server
#
# require "braintrust/contrib/rails/server"
#
# Braintrust::Contrib::Rails::Server::Engine.configure do |config|
#   config.evaluators = {
#     "my-classifier" => MyClassifier.new
#   }
#
#   # Default is :clerk_token. Use :none only for local development without
#   # incoming request authentication. Outgoing Braintrust API calls still need
#   # normal Braintrust credentials.
#   config.auth = :clerk_token
# end

# ---------------------------------------------------------------------------
# config/routes.rb
# ---------------------------------------------------------------------------

# Rails.application.routes.draw do
#   mount Braintrust::Contrib::Rails::Server::Engine, at: "/braintrust"
# end

puts "Braintrust Rails Engine example — see comments for usage"