Ruby on Rails - uninitialized constant SiteController::API

I am building a API to a recieve stats for a specific game. Right now I am able to recieve stats once every time I start my server. After looking up 1 Player I and I'm trying to refresh the page to look up another(right now I am using gets.chomp via console to enter the names) I get the following error:

uninitialized constant SiteController::API

class SiteController < ApplicationController
  require_relative '../../lib/api'


  def stats
    api = API.new(
        username: 'someusername',
        password: 'somepassword',
        token: 'sometoken',
    )

    puts "Username: "
    username = gets.chomp
    puts "Platform: "
    platform = gets.chomp

    @allStats = api.getStats(username, platform)
  end

end

api.rb

require 'net/http'
require 'json'

class API
  def initialize(auth)
    @auth = auth
    @Token = getToken['access_token']
  end

  def TOKEN_URL
    'https://antoherlink.com'
  end

  def EXCHANGE_URL
    'https://somelink.com'
  end

  def LOOKUP_URL(username)
    "https://somelink.com{username}"
  end

  def STATS_URL(id)
    "https://somelink.com"
  end

  def httpGet(url, auth)
    uri = URI(url)

    req = Net::HTTP::Get.new(uri)
    req['Authorization'] = auth

    res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
      http.request(req)
    end

    JSON.parse(res.body)
  end

  def httpPost(url, params, auth)
    uri = URI(url)

    req = Net::HTTP::Post.new(uri)
    req.set_form_data(params)
    req['Authorization'] = auth

    res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
      http.request(req)
    end

    JSON.parse(res.body)
  end

  def getToken
    params = {
        grant_type: 'password',
        includePerms: true,
        username: @auth[:username],
        password: @auth[:password]
    }

    httpPost(TOKEN_URL(), params, "basic #{@auth[:token]}")
  end

  def getExchangeCode
    httpGet(EXCHANGE_URL(), "bearer #{getToken['access_token']}")['code']
  end

  def getToken
    params = {
        grant_type: 'exchange_code',
        includePerms: true,
        token_type: 'eg1',
        exchange_code: getExchangeCode
    }

    httpPost(TOKEN_URL(), params, "basic #{@auth[:anothertoken]}")
  end

  def lookup(username)
    httpGet(LOOKUP_URL(username), "bearer #{@Token}")
  end

  def getRawStats(username)
    httpGet(STATS_URL(lookup(username)['id']), "bearer #{@Token}")
  end

  def getStats(username, platform)
    result = decodeRawStats(getRawStats(username), platform)

What did I miss?