Set up initial handshake for Strava webhooks

app.rb

require 'json'
require 'sinatra'

class App < Sinatra::Base
  get '/event' do
    hub_challenge = params['hub.challenge']

    content_type :json
    { 'hub.challenge' => hub_challenge }.to_json
  end
end

config.ru

require 'sinatra'
require './app'
run App.new

Gemfile

source 'https://rubygems.org'

gem 'sinatra'

group :development do
  gem 'sinatra-contrib'
end