diff --git a/app/jobs/crossref_doi_job.rb b/app/jobs/crossref_doi_job.rb
new file mode 100644
index 000000000..35acaf960
--- /dev/null
+++ b/app/jobs/crossref_doi_job.rb
@@ -0,0 +1,62 @@
+class CrossrefDoiJob < ActiveJob::Base
+  queue_as :lupo_background
+
+  # retry_on ActiveRecord::Deadlocked, wait: 10.seconds, attempts: 3
+  # retry_on Faraday::TimeoutError, wait: 10.minutes, attempts: 3
+
+  # discard_on ActiveJob::DeserializationError
+
+  def perform(id)
+    logger = Logger.new(STDOUT)
+
+    doi = doi_from_url(id)
+    return {} unless doi.present?
+
+    # check whether DOI has been registered with DataCite already
+    result = Doi.find_by_id(doi).results.first
+    return {} unless result.blank?
+
+    # otherwise store Crossref metadata with DataCite 
+    # using client crossref.citations and DataCite XML
+    xml = Base64.strict_encode64(id)
+    attributes = {
+      "xml" => xml,
+      "source" => "levriero",
+      "event" => "publish" }.compact
+
+    data = {
+      "data" => {
+        "type" => "dois",
+        "attributes" => attributes,
+        "relationships" => {
+          "client" =>  {
+            "data" => {
+              "type" => "clients",
+              "id" => "crossref.citations"
+            }
+          }
+        }
+      }
+    }
+
+    url = "http://localhost/dois/#{doi}"
+    response = Maremma.put(url, accept: 'application/vnd.api+json', 
+                                content_type: 'application/vnd.api+json',
+                                data: data.to_json, 
+                                username: ENV["ADMIN_USERNAME"],
+                                password: ENV["ADMIN_PASSWORD"])
+
+    if [200, 201].include?(response.status)
+      logger.info "DOI #{doi} created."
+    else
+      logger.warn response.body["errors"]
+    end
+  end
+
+  def doi_from_url(url)
+    if /\A(?:(http|https):\/\/(dx\.)?(doi.org|handle.test.datacite.org)\/)?(doi:)?(10\.\d{4,5}\/.+)\z/.match(url)
+      uri = Addressable::URI.parse(url)
+      uri.path.gsub(/^\//, '').downcase
+    end
+  end
+end
\ No newline at end of file
diff --git a/app/jobs/url_job.rb b/app/jobs/url_job.rb
index 7013bade2..bbaed531c 100644
--- a/app/jobs/url_job.rb
+++ b/app/jobs/url_job.rb
@@ -14,13 +14,13 @@ def perform(doi_id)
       response = Doi.get_doi(doi: doi.doi)
       url = response.body.dig('data', 'values', 0, 'data', 'value')
       if url.present?
-        if (doi.is_registered_or_findable? || %w(europ ethz).include?(doi.provider_id)) && doi.minted.blank?
+        if (doi.is_registered_or_findable? || %w(europ ethz crossref).include?(doi.provider_id)) && doi.minted.blank?
           doi.update_attributes(url: url, minted: Time.zone.now)
         else
           doi.update_attributes(url: url)
         end
 
-        doi.update_attributes(aasm_state: "findable") if %w(europ ethz).include?(doi.provider_id)
+        doi.update_attributes(aasm_state: "findable") if %w(europ ethz crossref).include?(doi.provider_id)
 
         doi.__elasticsearch__.index_document
 
diff --git a/app/models/concerns/indexable.rb b/app/models/concerns/indexable.rb
index 87734a40c..7c8b6ec69 100644
--- a/app/models/concerns/indexable.rb
+++ b/app/models/concerns/indexable.rb
@@ -106,6 +106,10 @@ def query(query, options={})
         from = 0
         search_after = [options.dig(:page, :cursor)]
         sort = [{ _id: { order: 'asc' }}]
+      elsif self.name == "Event" && options.dig(:page, :cursor).present?
+        from = 0
+        search_after = [options.dig(:page, :cursor)]
+        sort = [{ _id: { order: 'asc' }}]
       elsif self.name == "Activity" && options.dig(:page, :cursor).present?
         from = 0
         search_after = [options.dig(:page, :cursor)]
diff --git a/app/models/event.rb b/app/models/event.rb
index 9b77b37ea..23e6a5068 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -5,6 +5,9 @@ class Event < ActiveRecord::Base
   # include event processing
   include Processable
 
+  # include helper methods for models
+  include Modelable
+
   # include doi normalization
   include Identifiable
 
@@ -340,6 +343,76 @@ def self.import_by_id(options={})
     logger.info "[Elasticsearch] Imported #{count} events with IDs #{id} - #{(id + 499)}."
   end
 
+  def self.update_crossref(options={})
+    logger = Logger.new(STDOUT)
+
+    size = (options[:size] || 1000).to_i
+
+    response = Event.query(nil, source_id: "crossref", page: { size: 1, cursor: 0 })
+    logger.info "[Update] #{response.results.total} events for source crossref."
+
+    if response.results.total > 0
+      # walk through results using cursor
+      cursor = 0
+
+      while response.results.results.length > 0 do
+        response = Event.query(nil, source_id: "crossref", page: { size: size, cursor: cursor })
+        break unless response.results.results.length > 0
+
+        logger.info "[Update] Updating #{response.results.results.length} crossref events starting with _id #{cursor + 1}."
+        cursor = response.results.to_a.last[:sort].first.to_i
+
+        response.results.results.each do |e|
+          CrossrefDoiJob.perform_later(e.subj_id)
+        end
+      end
+    end
+
+    response.results.total
+  end
+
+  def self.update_datacite_crossref(options={})
+    logger = Logger.new(STDOUT)
+
+    size = (options[:size] || 1000).to_i
+
+    response = Event.query(nil, source_id: "datacite_crossref", page: { size: 1, cursor: 0 })
+    logger.info "[Update] #{response.results.total} events for source datacite_crossref."
+
+    if response.results.total > 0
+      # walk through results using cursor
+      cursor = 0
+
+      while response.results.results.length > 0 do
+        response = Event.query(nil, source_id: "crossref", page: { size: size, cursor: cursor })
+        break unless response.results.results.length > 0
+
+        logger.info "[Update] Updating #{response.results.results.length} datacite_crossref events starting with _id #{cursor + 1}."
+        cursor = response.results.to_a.last[:sort].first.to_i
+
+        response.results.results.each do |e|
+          CrossrefDoiJob.perform_later(e.obj_id)
+        end
+      end
+    end
+
+    response.results.total
+  end
+
+  def self.get_crossref_metadata(id)
+    doi = doi_from_url(id)
+    return {} unless doi.present?
+
+    # check whether DOI has been registered with DataCite already
+    result = Doi.find_by_id(doi).results.first
+    if result.blank?
+      # otherwise store Crossref metadata with DataCite 
+      # using client crossref.citations and DataCite XML
+      xml = Base64.strict_encode64(id)
+      Doi.create({ xml: xml, source: "levriero", event: "publish", client_id: "crossref.citations" }, :without_protection => true)
+    end
+  end
+
   def to_param  # overridden, use uuid instead of id
     uuid
   end
@@ -356,6 +429,7 @@ def send_callback
                "timestamp" => timestamp }}
     Maremma.post(callback, data: data.to_json, token: ENV['API_KEY'])
   end
+
   def access_method
     if relation_type_id.to_s =~ /(requests|investigations)/
       relation_type_id.split("-").last if relation_type_id.present?
diff --git a/config/application.rb b/config/application.rb
index c1e5f8d66..e1f005e56 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -36,6 +36,7 @@
 ENV['SITE_TITLE'] ||= "DataCite REST API"
 ENV['LOG_LEVEL'] ||= "info"
 ENV['CONCURRENCY'] ||= "25"
+ENV['API_URL'] ||= "https://api.test.datacite.org"
 ENV['CDN_URL'] ||= "https://assets.datacite.org"
 ENV['BRACCO_URL'] ||= "https://doi.datacite.org"
 ENV['GITHUB_URL'] ||= "https://github.com/datacite/lupo"
diff --git a/lib/tasks/event.rake b/lib/tasks/event.rake
index d4b66417f..6fd84073f 100644
--- a/lib/tasks/event.rake
+++ b/lib/tasks/event.rake
@@ -22,3 +22,23 @@ namespace :event do
     Event.import_by_ids(from_id: from_id, until_id: until_id)
   end
 end
+
+namespace :crossref do
+  desc 'Import dois for all events'
+  task :import_doi => :environment do
+    from_id = (ENV['FROM_ID'] || 1).to_i
+    until_id = (ENV['UNTIL_ID'] || Event.maximum(:id)).to_i
+
+    Event.update_crossref(from_id: from_id, until_id: until_id)
+  end
+end
+
+namespace :datacite_crossref do
+  desc 'Import dois for all events'
+  task :import_doi => :environment do
+    from_id = (ENV['FROM_ID'] || 1).to_i
+    until_id = (ENV['UNTIL_ID'] || Event.maximum(:id)).to_i
+
+    Event.update_datacite_crossref(from_id: from_id, until_id: until_id)
+  end
+end