diff --git a/app/controllers/api/v1/registrant/contacts_controller.rb b/app/controllers/api/v1/registrant/contacts_controller.rb
index 10f9abacf..e11458ff8 100644
--- a/app/controllers/api/v1/registrant/contacts_controller.rb
+++ b/app/controllers/api/v1/registrant/contacts_controller.rb
@@ -19,15 +19,16 @@ module Api
           end
 
           contacts = current_user_contacts.limit(limit).offset(offset)
-          serialized_contacts = contacts.collect { |contact| serialize_contact(contact) }
+          serialized_contacts = contacts.collect { |contact| serialize_contact(contact, false) }
           render json: serialized_contacts
         end
 
         def show
           contact = current_user_contacts.find_by(uuid: params[:uuid])
+          links = params[:links] == 'true'
 
           if contact
-            render json: serialize_contact(contact)
+            render json: serialize_contact(contact, links)
           else
             render json: { errors: [{ base: ['Contact not found'] }] }, status: :not_found
           end
@@ -85,7 +86,7 @@ module Api
             contact.registrar.notify(action)
           end
 
-          render json: serialize_contact(contact)
+          render json: serialize_contact(contact, false)
         end
 
         private
@@ -96,8 +97,8 @@ module Api
           current_registrant_user.direct_contacts
         end
 
-        def serialize_contact(contact)
-          Serializers::RegistrantApi::Contact.new(contact).to_json
+        def serialize_contact(contact, links)
+          Serializers::RegistrantApi::Contact.new(contact, links).to_json
         end
       end
     end
diff --git a/app/controllers/api/v1/registrant/domains_controller.rb b/app/controllers/api/v1/registrant/domains_controller.rb
index b985ef390..73b534598 100644
--- a/app/controllers/api/v1/registrant/domains_controller.rb
+++ b/app/controllers/api/v1/registrant/domains_controller.rb
@@ -7,6 +7,7 @@ module Api
         def index
           limit = params[:limit] || 200
           offset = params[:offset] || 0
+          simple = params[:simple] == 'true' || false
 
           if limit.to_i > 200 || limit.to_i < 1
             render(json: { errors: [{ limit: ['parameter is out of range'] }] },
@@ -18,21 +19,20 @@ module Api
                    status: :bad_request) && return
           end
 
-          @domains = current_user_domains.limit(limit).offset(offset)
-
-          serialized_domains = @domains.map do |item|
-            serializer = Serializers::RegistrantApi::Domain.new(item)
+          domains = current_user_domains
+          serialized_domains = domains.limit(limit).offset(offset).map do |item|
+            serializer = Serializers::RegistrantApi::Domain.new(item, simplify: simple)
             serializer.to_json
           end
 
-          render json: serialized_domains
+          render json: { count: domains.count, domains: serialized_domains }
         end
 
         def show
           @domain = current_user_domains.find_by(uuid: params[:uuid])
 
           if @domain
-            serializer = Serializers::RegistrantApi::Domain.new(@domain)
+            serializer = Serializers::RegistrantApi::Domain.new(@domain, simplify: false)
             render json: serializer.to_json
           else
             render json: { errors: [{ base: ['Domain not found'] }] }, status: :not_found
diff --git a/app/models/contact.rb b/app/models/contact.rb
index 8a154c50c..e30312b4a 100644
--- a/app/models/contact.rb
+++ b/app/models/contact.rb
@@ -347,19 +347,24 @@ class Contact < ApplicationRecord
     @desc = {}
 
     registrant_domains.each do |dom|
-      @desc[dom.name] ||= []
-      @desc[dom.name] << :registrant
+      @desc[dom.name] ||= { id: dom.uuid, roles: [] }
+      @desc[dom.name][:roles] << :registrant
     end
 
     domain_contacts.each do |dc|
-      @desc[dc.domain.name] ||= []
-      @desc[dc.domain.name] << dc.name.downcase.to_sym
+      @desc[dc.domain.name] ||= { id: dc.domain.uuid, roles: [] }
+      @desc[dc.domain.name][:roles] << dc.name.downcase.to_sym
       @desc[dc.domain.name] = @desc[dc.domain.name].compact
     end
 
     @desc
   end
 
+  def related_domains
+    a = related_domain_descriptions
+    a.keys.map { |d| { name: d, id: a[d][:id], roles: a[d][:roles] } }
+  end
+
   def status_notes_array=(notes)
     self.status_notes = {}
     notes ||= []
diff --git a/lib/serializers/registrant_api/contact.rb b/lib/serializers/registrant_api/contact.rb
index dd36b4400..023544174 100644
--- a/lib/serializers/registrant_api/contact.rb
+++ b/lib/serializers/registrant_api/contact.rb
@@ -1,14 +1,15 @@
 module Serializers
   module RegistrantApi
     class Contact
-      attr_reader :contact
+      attr_reader :contact, :links
 
-      def initialize(contact)
+      def initialize(contact, links)
         @contact = contact
+        @links = links
       end
 
-      def to_json
-        {
+      def to_json(_obj = nil)
+        obj = {
           id: contact.uuid,
           name: contact.name,
           code: contact.code,
@@ -31,6 +32,10 @@ module Serializers
           statuses: contact.statuses,
           disclosed_attributes: contact.disclosed_attributes,
         }
+
+        obj[:links] = contact.related_domains if @links
+
+        obj
       end
     end
   end
diff --git a/lib/serializers/registrant_api/domain.rb b/lib/serializers/registrant_api/domain.rb
index 542f2d0de..2359d77c9 100644
--- a/lib/serializers/registrant_api/domain.rb
+++ b/lib/serializers/registrant_api/domain.rb
@@ -3,11 +3,14 @@ module Serializers
     class Domain
       attr_reader :domain
 
-      def initialize(domain)
+      def initialize(domain, simplify: false)
         @domain = domain
+        @simplify = simplify
       end
 
-      def to_json
+      def to_json(_obj = nil)
+        return simple_object if @simplify
+
         {
           id: domain.uuid,
           name: domain.name,
@@ -49,6 +52,17 @@ module Serializers
 
       private
 
+      def simple_object
+        {
+          id: domain.uuid, name: domain.name, registered_at: domain.registered_at,
+          valid_to: domain.valid_to, outzone_at: domain.outzone_at, statuses: domain.statuses,
+          registrant_verification_asked_at: domain.registrant_verification_asked_at,
+          registrar: { name: domain.registrar.name, website: domain.registrar.website },
+          registrant: { name: domain.registrant.name, id: domain.registrant.uuid,
+                        phone: domain.registrant.phone, email: domain.registrant.email }
+        }
+      end
+
       def dnssec_keys
         domain.dnskeys.map do |key|
           "#{key.flags} #{key.protocol} #{key.alg} #{key.public_key}"
diff --git a/test/integration/api/registrant/registrant_api_domains_test.rb b/test/integration/api/registrant/registrant_api_domains_test.rb
index 22516fecc..61d635e5f 100644
--- a/test/integration/api/registrant/registrant_api_domains_test.rb
+++ b/test/integration/api/registrant/registrant_api_domains_test.rb
@@ -50,10 +50,10 @@ class RegistrantApiDomainsTest < ApplicationIntegrationTest
     assert_equal(200, response.status)
 
     response_json = JSON.parse(response.body, symbolize_names: true)
-    array_of_domain_names = response_json.map { |x| x[:name] }
+    array_of_domain_names = response_json[:domains].map { |x| x[:name] }
     assert(array_of_domain_names.include?('hospital.test'))
 
-    array_of_domain_registrars = response_json.map { |x| x[:registrar] }
+    array_of_domain_registrars = response_json[:domains].map { |x| x[:registrar] }
     assert(array_of_domain_registrars.include?({name: 'Good Names', website: nil}))
   end
 
@@ -63,12 +63,12 @@ class RegistrantApiDomainsTest < ApplicationIntegrationTest
     response_json = JSON.parse(response.body, symbolize_names: true)
 
     assert_equal(200, response.status)
-    assert_equal(2, response_json.count)
+    assert_equal(2, response_json[:domains].count)
 
     get '/api/v1/registrant/domains', headers: @auth_headers
     response_json = JSON.parse(response.body, symbolize_names: true)
 
-    assert_equal(4, response_json.count)
+    assert_equal(4, response_json[:domains].count)
   end
 
   def test_root_does_not_accept_limit_higher_than_200
diff --git a/test/lib/serializers/registrant_api/contact_test.rb b/test/lib/serializers/registrant_api/contact_test.rb
index 165c91e00..8b84abd38 100644
--- a/test/lib/serializers/registrant_api/contact_test.rb
+++ b/test/lib/serializers/registrant_api/contact_test.rb
@@ -4,7 +4,7 @@ require 'serializers/registrant_api/contact'
 class SerializersRegistrantApiContactTest < ActiveSupport::TestCase
   def setup
     @contact = contacts(:william)
-    @serializer = Serializers::RegistrantApi::Contact.new(@contact)
+    @serializer = Serializers::RegistrantApi::Contact.new(@contact, false)
     @json = @serializer.to_json
   end