diff --git a/.rubocop.yml b/.rubocop.yml
index 1828876dd..b79b85ffa 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -11,6 +11,9 @@ Style/ClassAndModuleChildren:
 
 Metrics/LineLength:
   Max: 100
+  Exclude:
+    - spec/**/*.rb
+    - examples/**/*.rb
 
 Metrics/MethodLength:
   Max: 25
@@ -18,3 +21,11 @@ Metrics/MethodLength:
 Metrics/AbcSize:
   Max: 25
 
+Metrics/BlockLength:
+  Max: 100
+  Exclude:
+    - spec/pdc/**/*.rb
+    - examples/**/*.rb
+
+Naming/PredicateName:
+  Enabled: false
diff --git a/lib/pdc/base.rb b/lib/pdc/base.rb
index 1988c9444..d11a56b63 100644
--- a/lib/pdc/base.rb
+++ b/lib/pdc/base.rb
@@ -7,6 +7,7 @@ class Base
     include PDC::Resource::Attributes
     include PDC::Resource::Scopes
     include PDC::Resource::RestApi
+    include PDC::Resource::Associations
 
     scope :page, ->(value) { where(page: value) }
     scope :page_size, ->(value) { where(page_size: value) }
diff --git a/lib/pdc/resource.rb b/lib/pdc/resource.rb
index df80da235..b14847864 100644
--- a/lib/pdc/resource.rb
+++ b/lib/pdc/resource.rb
@@ -10,3 +10,4 @@
 require 'pdc/resource/relation'
 require 'pdc/resource/rest_api'
 require 'pdc/resource/wip'
+require 'pdc/resource/associations'
diff --git a/lib/pdc/resource/associations.rb b/lib/pdc/resource/associations.rb
new file mode 100644
index 000000000..d365593cc
--- /dev/null
+++ b/lib/pdc/resource/associations.rb
@@ -0,0 +1,44 @@
+require 'pdc/resource/associations/has_many'
+require 'pdc/resource/associations/association'
+require 'pdc/resource/associations/builder'
+require 'pdc/resource/associations/has_one'
+
+module PDC::Resource
+  module Associations
+    extend ActiveSupport::Concern
+
+    included do
+      class_attribute :associations
+      self.associations = {}.freeze
+    end
+
+    module ClassMethods
+      def has_many(name, options = {})
+        create_association(name, HasMany, options)
+
+        define_method "#{name.to_s.singularize}_ids=" do |ids|
+          attributes[name] = []
+          ids.reject(&:blank?).each { |id| association(name).build(id: id) }
+        end
+
+        define_method "#{name.to_s.singularize}_ids" do
+          association(name).map(&:id)
+        end
+      end
+
+      def has_one(name, options = {})
+        create_association(name, HasOne, options)
+
+        define_method "build_#{name}" do |attributes = nil|
+          association(name).build(attributes)
+        end
+      end
+
+      private
+
+      def create_association(name, type, options)
+        self.associations = associations.merge(name => Builder.new(self, name, type, options))
+      end
+    end
+  end
+end
diff --git a/lib/pdc/resource/associations/association.rb b/lib/pdc/resource/associations/association.rb
new file mode 100644
index 000000000..ce7a5de4e
--- /dev/null
+++ b/lib/pdc/resource/associations/association.rb
@@ -0,0 +1,25 @@
+require 'pdc/resource/relation'
+
+module PDC::Resource
+  module Associations
+    class Association < Relation
+      attr_reader :parent, :name
+
+      def initialize(klass, parent, name, options = {})
+        super(klass, options)
+        @parent = parent
+        @name = name
+      end
+
+      def load
+        find_one! # Override for plural associations that return an association object
+      end
+
+      private
+
+      def foreign_key
+        (@options[:foreign_key] || "#{parent.class.model_name.element}_id").to_sym
+      end
+    end
+  end
+end
diff --git a/lib/pdc/resource/associations/builder.rb b/lib/pdc/resource/associations/builder.rb
new file mode 100644
index 000000000..e4a91d9f8
--- /dev/null
+++ b/lib/pdc/resource/associations/builder.rb
@@ -0,0 +1,44 @@
+require 'active_support/dependencies'
+
+module PDC::Resource
+  module Associations
+    class Builder
+      def initialize(parent_class, name, type, options = {})
+        @parent_class = parent_class
+        @name = name
+        @type = type
+        @options = options
+      end
+
+      def build(parent)
+        @type.new(klass, parent, @name, @options)
+      end
+
+      def klass
+        @klass ||= custom_class || compute_class(@name)
+      end
+
+      private
+
+      def custom_class
+        @options[:class_name].constantize if @options[:class_name]
+      end
+
+      # https://github.com/rails/rails/blob/70ac072976c8cc6f013f0df3777e54ccae3f4f8c/activerecord/lib/active_record/inheritance.rb#L132-L150
+      def compute_class(type_name)
+        parent_name = @parent_class.to_s
+        type_name = type_name.to_s.classify
+
+        candidates = []
+        parent_name.scan(/::|$/) { candidates.unshift "#{$`}::#{type_name}" }
+        candidates << type_name
+
+        candidates.each do |candidate|
+          constant = ActiveSupport::Dependencies.safe_constantize(candidate)
+          return constant if candidate == constant.to_s
+        end
+        raise NameError.new("uninitialized constant #{candidates.first}", candidates.first)
+      end
+    end
+  end
+end
diff --git a/lib/pdc/resource/associations/has_many.rb b/lib/pdc/resource/associations/has_many.rb
new file mode 100644
index 000000000..88855a4c5
--- /dev/null
+++ b/lib/pdc/resource/associations/has_many.rb
@@ -0,0 +1,23 @@
+require 'pdc/resource/associations/association'
+
+module PDC::Resource
+  module Associations
+    class HasMany < Association
+      def initialize(*args)
+        super
+        @options.reverse_merge!(uri: "#{parent_path}/:#{foreign_key}/#{@name}/(:#{primary_key})")
+        @params[foreign_key] = parent.id
+      end
+
+      def load
+        self
+      end
+
+      private
+
+      def parent_path
+        parent.class.model_name.element.pluralize
+      end
+    end
+  end
+end
diff --git a/lib/pdc/resource/associations/has_one.rb b/lib/pdc/resource/associations/has_one.rb
new file mode 100644
index 000000000..64ba9cd03
--- /dev/null
+++ b/lib/pdc/resource/associations/has_one.rb
@@ -0,0 +1,29 @@
+module PDC::Resource
+  module Associations
+    class HasOne < Association
+      def initialize(*args)
+        super
+        @options.reverse_merge!(uri: "#{parent.class.model_name.plural}/:#{foreign_key}/#{@name}")
+        collect_params
+      end
+
+      def collect_params
+        p_mapping = parent.class.mapping
+        s_foreign_key = foreign_key.to_s
+        if s_foreign_key.include? '/'
+          s_foreign_key.split('/').each do |fk|
+            p_mapping_value = p_mapping[fk.to_sym]
+            @params[fk] =
+              if p_mapping && p_mapping_value
+                parent.attributes[p_mapping_value.to_sym]
+              else
+                parent.attributes[fk]
+              end
+          end
+        else
+          @params[foreign_key] = parent.id
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pdc/resource/attributes.rb b/lib/pdc/resource/attributes.rb
index 964c39b51..9c28fffc1 100644
--- a/lib/pdc/resource/attributes.rb
+++ b/lib/pdc/resource/attributes.rb
@@ -90,7 +90,8 @@ def use_setters(attributes)
     end
 
     def method_missing(name, *args, &block)
-      if attribute?(name) then attribute(name)
+      if association?(name) then association(name).load
+      elsif attribute?(name) then attribute(name)
       elsif predicate?(name)   then predicate(name)
       elsif setter?(name)      then set_attribute(name, args.first)
       else super
@@ -98,7 +99,15 @@ def method_missing(name, *args, &block)
     end
 
     def respond_to_missing?(name, include_private = false)
-      attribute?(name) || predicate?(name) || setter?(name) || super
+      association?(name) || attribute?(name) || predicate?(name) || setter?(name) || super
+    end
+
+    def association?(name)
+      associations.key?(name)
+    end
+
+    def association(name)
+      associations[name].build(self)
     end
 
     def attribute?(name)
diff --git a/lib/pdc/resource/identity.rb b/lib/pdc/resource/identity.rb
index e2188d6ee..edd8c2244 100644
--- a/lib/pdc/resource/identity.rb
+++ b/lib/pdc/resource/identity.rb
@@ -24,6 +24,14 @@ def resource_path
         @resource_path ||= model_name.collection.sub(%r{^pdc\/}, '').tr('_', '-')
       end
 
+      def mapping
+        @mapping || {}
+      end
+
+      def mapping=(mapping = {})
+        @mapping = mapping
+      end
+
       private
 
       def default_uri
diff --git a/lib/pdc/resource/relation.rb b/lib/pdc/resource/relation.rb
index 75db78d68..88b508ad3 100644
--- a/lib/pdc/resource/relation.rb
+++ b/lib/pdc/resource/relation.rb
@@ -12,6 +12,7 @@ class Relation
 
     attr_reader :klass
     attr_writer :params
+    delegate :to_ary, :[], :any?, :empty?, :last, :size, :metadata, to: :contents!
 
     alias all to_a
 
diff --git a/spec/fixtures/vcr/array_like_behavior.yml b/spec/fixtures/vcr/array_like_behavior.yml
new file mode 100644
index 000000000..1276267c6
--- /dev/null
+++ b/spec/fixtures/vcr/array_like_behavior.yml
@@ -0,0 +1,141 @@
+---
+http_interactions:
+- request:
+    method: get
+    uri: https://pdc.host.dev.eng.pek2.redhat.com/rest_api/v1/releases/?product_version=ceph-1
+    body:
+      encoding: US-ASCII
+      string: ''
+    headers:
+      User-Agent:
+      - Faraday v0.9.2
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Wed, 03 Jan 2018 08:14:47 GMT
+      Server:
+      - Apache/2.4.6 (Red Hat Enterprise Linux) OpenSSL/1.0.1e-fips mod_auth_kerb/5.4
+        mod_wsgi/3.4 Python/2.7.5
+      Expires:
+      - Wed, 03 Jan 2018 08:15:17 GMT
+      Vary:
+      - Accept,Cookie
+      Last-Modified:
+      - Tue, 26 Sep 2017 08:04:24 GMT
+      Allow:
+      - GET, POST, PUT, PATCH, HEAD, OPTIONS
+      Cache-Control:
+      - max-age=30
+      X-Frame-Options:
+      - SAMEORIGIN
+      Transfer-Encoding:
+      - chunked
+      Content-Type:
+      - application/json
+    body:
+      encoding: UTF-8
+      string: '{"count":2,"next":null,"previous":null,"results":[{"release_id":"ceph-1.3@rhel-7","short":"ceph","version":"1.3","name":"Red
+        Hat Ceph Storage","base_product":"rhel-7","active":true,"product_version":"ceph-1","release_type":"ga","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":true,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null},{"release_id":"ceph-1.3-updates@rhel-7","short":"ceph","version":"1.3","name":"Red
+        Hat Ceph Storage","base_product":"rhel-7","active":true,"product_version":"ceph-1","release_type":"updates","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":false,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null}]}'
+    http_version: 
+  recorded_at: Wed, 03 Jan 2018 08:14:48 GMT
+- request:
+    method: get
+    uri: https://pdc.host.dev.eng.pek2.redhat.com/rest_api/v1/releases/?product_version=ceph-1
+    body:
+      encoding: US-ASCII
+      string: ''
+    headers:
+      User-Agent:
+      - Faraday v0.9.2
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Wed, 03 Jan 2018 08:14:48 GMT
+      Server:
+      - Apache/2.4.6 (Red Hat Enterprise Linux) OpenSSL/1.0.1e-fips mod_auth_kerb/5.4
+        mod_wsgi/3.4 Python/2.7.5
+      Expires:
+      - Wed, 03 Jan 2018 08:15:18 GMT
+      Vary:
+      - Accept,Cookie
+      Last-Modified:
+      - Tue, 26 Sep 2017 08:04:24 GMT
+      Allow:
+      - GET, POST, PUT, PATCH, HEAD, OPTIONS
+      Cache-Control:
+      - max-age=30
+      X-Frame-Options:
+      - SAMEORIGIN
+      Transfer-Encoding:
+      - chunked
+      Content-Type:
+      - application/json
+    body:
+      encoding: UTF-8
+      string: '{"count":2,"next":null,"previous":null,"results":[{"release_id":"ceph-1.3@rhel-7","short":"ceph","version":"1.3","name":"Red
+        Hat Ceph Storage","base_product":"rhel-7","active":true,"product_version":"ceph-1","release_type":"ga","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":true,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null},{"release_id":"ceph-1.3-updates@rhel-7","short":"ceph","version":"1.3","name":"Red
+        Hat Ceph Storage","base_product":"rhel-7","active":true,"product_version":"ceph-1","release_type":"updates","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":false,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null}]}'
+    http_version: 
+  recorded_at: Wed, 03 Jan 2018 08:14:48 GMT
+- request:
+    method: get
+    uri: https://pdc.host.dev.eng.pek2.redhat.com/rest_api/v1/releases/?product_version=ceph-1
+    body:
+      encoding: US-ASCII
+      string: ''
+    headers:
+      User-Agent:
+      - Faraday v0.9.2
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Wed, 03 Jan 2018 08:14:48 GMT
+      Server:
+      - Apache/2.4.6 (Red Hat Enterprise Linux) OpenSSL/1.0.1e-fips mod_auth_kerb/5.4
+        mod_wsgi/3.4 Python/2.7.5
+      Expires:
+      - Wed, 03 Jan 2018 08:15:18 GMT
+      Vary:
+      - Accept,Cookie
+      Last-Modified:
+      - Tue, 26 Sep 2017 08:04:24 GMT
+      Allow:
+      - GET, POST, PUT, PATCH, HEAD, OPTIONS
+      Cache-Control:
+      - max-age=30
+      X-Frame-Options:
+      - SAMEORIGIN
+      Transfer-Encoding:
+      - chunked
+      Content-Type:
+      - application/json
+    body:
+      encoding: UTF-8
+      string: '{"count":2,"next":null,"previous":null,"results":[{"release_id":"ceph-1.3@rhel-7","short":"ceph","version":"1.3","name":"Red
+        Hat Ceph Storage","base_product":"rhel-7","active":true,"product_version":"ceph-1","release_type":"ga","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":true,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null},{"release_id":"ceph-1.3-updates@rhel-7","short":"ceph","version":"1.3","name":"Red
+        Hat Ceph Storage","base_product":"rhel-7","active":true,"product_version":"ceph-1","release_type":"updates","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":false,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null}]}'
+    http_version: 
+  recorded_at: Wed, 03 Jan 2018 08:14:48 GMT
+recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr/find_on_has_many_association.yml b/spec/fixtures/vcr/find_on_has_many_association.yml
new file mode 100644
index 000000000..d7255cf05
--- /dev/null
+++ b/spec/fixtures/vcr/find_on_has_many_association.yml
@@ -0,0 +1,48 @@
+---
+http_interactions:
+- request:
+    method: get
+    uri: https://pdc.host.dev.eng.pek2.redhat.com/rest_api/v1/releases/?product_version=dp-1&release_id=dp-1.0
+    body:
+      encoding: US-ASCII
+      string: ''
+    headers:
+      User-Agent:
+      - Faraday v0.9.2
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Wed, 03 Jan 2018 08:14:47 GMT
+      Server:
+      - Apache/2.4.6 (Red Hat Enterprise Linux) OpenSSL/1.0.1e-fips mod_auth_kerb/5.4
+        mod_wsgi/3.4 Python/2.7.5
+      Expires:
+      - Wed, 03 Jan 2018 08:15:17 GMT
+      Vary:
+      - Accept,Cookie
+      Last-Modified:
+      - Tue, 26 Sep 2017 08:04:24 GMT
+      Allow:
+      - GET, POST, PUT, PATCH, HEAD, OPTIONS
+      Cache-Control:
+      - max-age=30
+      X-Frame-Options:
+      - SAMEORIGIN
+      Transfer-Encoding:
+      - chunked
+      Content-Type:
+      - application/json
+    body:
+      encoding: UTF-8
+      string: '{"count":1,"next":null,"previous":null,"results":[{"release_id":"dp-1.0","short":"dp","version":"1.0","name":"Dummy
+        Product","base_product":null,"active":true,"product_version":"dp-1","release_type":"ga","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":false,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null}]}'
+    http_version: 
+  recorded_at: Wed, 03 Jan 2018 08:14:47 GMT
+recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr/has_many_association.yml b/spec/fixtures/vcr/has_many_association.yml
new file mode 100644
index 000000000..3d3a0a669
--- /dev/null
+++ b/spec/fixtures/vcr/has_many_association.yml
@@ -0,0 +1,48 @@
+---
+http_interactions:
+- request:
+    method: get
+    uri: https://pdc.host.dev.eng.pek2.redhat.com/rest_api/v1/releases/?product_version=dp-1
+    body:
+      encoding: US-ASCII
+      string: ''
+    headers:
+      User-Agent:
+      - Faraday v0.9.2
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Wed, 03 Jan 2018 08:14:47 GMT
+      Server:
+      - Apache/2.4.6 (Red Hat Enterprise Linux) OpenSSL/1.0.1e-fips mod_auth_kerb/5.4
+        mod_wsgi/3.4 Python/2.7.5
+      Expires:
+      - Wed, 03 Jan 2018 08:15:17 GMT
+      Vary:
+      - Accept,Cookie
+      Last-Modified:
+      - Tue, 26 Sep 2017 08:04:24 GMT
+      Allow:
+      - GET, POST, PUT, PATCH, HEAD, OPTIONS
+      Cache-Control:
+      - max-age=30
+      X-Frame-Options:
+      - SAMEORIGIN
+      Transfer-Encoding:
+      - chunked
+      Content-Type:
+      - application/json
+    body:
+      encoding: UTF-8
+      string: '{"count":1,"next":null,"previous":null,"results":[{"release_id":"dp-1.0","short":"dp","version":"1.0","name":"Dummy
+        Product","base_product":null,"active":true,"product_version":"dp-1","release_type":"ga","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":false,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null}]}'
+    http_version: 
+  recorded_at: Wed, 03 Jan 2018 08:14:47 GMT
+recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr/has_one_assocation.yml b/spec/fixtures/vcr/has_one_assocation.yml
new file mode 100644
index 000000000..d74e21b02
--- /dev/null
+++ b/spec/fixtures/vcr/has_one_assocation.yml
@@ -0,0 +1,47 @@
+---
+http_interactions:
+- request:
+    method: get
+    uri: https://pdc.host.dev.eng.pek2.redhat.com/rest_api/v1/variant-cpes/?release=dp-1.0&variant_uid=Client
+    body:
+      encoding: US-ASCII
+      string: ''
+    headers:
+      User-Agent:
+      - Faraday v0.9.2
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Thu, 11 Jan 2018 13:34:52 GMT
+      Server:
+      - Apache/2.4.6 (Red Hat Enterprise Linux) OpenSSL/1.0.1e-fips mod_auth_kerb/5.4
+        mod_wsgi/3.4 Python/2.7.5
+      Expires:
+      - Thu, 11 Jan 2018 13:35:24 GMT
+      Vary:
+      - Accept,Cookie
+      Last-Modified:
+      - Thu, 11 Jan 2018 13:34:54 GMT
+      Allow:
+      - GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS
+      Cache-Control:
+      - max-age=30
+      X-Frame-Options:
+      - SAMEORIGIN
+      Transfer-Encoding:
+      - chunked
+      Content-Type:
+      - application/json
+    body:
+      encoding: UTF-8
+      string: '{"count":1,"next":null,"previous":null,"results":[{"id":5,"release":"dp-1.0","variant_uid":"Client","cpe":"cpe:/asdff"}]}'
+    http_version: 
+  recorded_at: Thu, 11 Jan 2018 13:34:54 GMT
+recorded_with: VCR 3.0.3
diff --git a/spec/fixtures/vcr/scopes_on_associations.yml b/spec/fixtures/vcr/scopes_on_associations.yml
new file mode 100644
index 000000000..d7255cf05
--- /dev/null
+++ b/spec/fixtures/vcr/scopes_on_associations.yml
@@ -0,0 +1,48 @@
+---
+http_interactions:
+- request:
+    method: get
+    uri: https://pdc.host.dev.eng.pek2.redhat.com/rest_api/v1/releases/?product_version=dp-1&release_id=dp-1.0
+    body:
+      encoding: US-ASCII
+      string: ''
+    headers:
+      User-Agent:
+      - Faraday v0.9.2
+      Accept-Encoding:
+      - gzip;q=1.0,deflate;q=0.6,identity;q=0.3
+      Accept:
+      - "*/*"
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Date:
+      - Wed, 03 Jan 2018 08:14:47 GMT
+      Server:
+      - Apache/2.4.6 (Red Hat Enterprise Linux) OpenSSL/1.0.1e-fips mod_auth_kerb/5.4
+        mod_wsgi/3.4 Python/2.7.5
+      Expires:
+      - Wed, 03 Jan 2018 08:15:17 GMT
+      Vary:
+      - Accept,Cookie
+      Last-Modified:
+      - Tue, 26 Sep 2017 08:04:24 GMT
+      Allow:
+      - GET, POST, PUT, PATCH, HEAD, OPTIONS
+      Cache-Control:
+      - max-age=30
+      X-Frame-Options:
+      - SAMEORIGIN
+      Transfer-Encoding:
+      - chunked
+      Content-Type:
+      - application/json
+    body:
+      encoding: UTF-8
+      string: '{"count":1,"next":null,"previous":null,"results":[{"release_id":"dp-1.0","short":"dp","version":"1.0","name":"Dummy
+        Product","base_product":null,"active":true,"product_version":"dp-1","release_type":"ga","compose_set":[],"integrated_with":null,"sigkey":null,"allow_buildroot_push":false,"allowed_debuginfo_services":[],"allowed_push_targets":[],"bugzilla":null,"dist_git":null,"brew":null,"product_pages":null,"errata":null}]}'
+    http_version: 
+  recorded_at: Wed, 03 Jan 2018 08:14:47 GMT
+recorded_with: VCR 3.0.3
diff --git a/spec/pdc/resource/associations_spec.rb b/spec/pdc/resource/associations_spec.rb
new file mode 100644
index 000000000..ae1dcf220
--- /dev/null
+++ b/spec/pdc/resource/associations_spec.rb
@@ -0,0 +1,114 @@
+require 'spec_helper'
+
+describe PDC::Resource::Associations do
+  subject { PDC::Resource::Associations }
+
+  before do
+    VCR.insert_cassette fixture_name
+  end
+
+  after do
+    VCR.eject_cassette
+  end
+
+  let(:site) { 'https://pdc.host.dev.eng.pek2.redhat.com' }
+
+  let(:releases_url1) do
+    URI.join(site, PDC.config.api_root, 'v1/releases/?product_version=ceph-1&release_id=ceph-1.3@rhel-7')
+  end
+
+  let(:releases_url2) do
+    URI.join(site, PDC.config.api_root, 'v1/releases/?product_version=ceph-1')
+  end
+
+  describe 'association' do
+    it 'association independence' do
+      assert_kind_of subject::HasMany, ProductVersion.new.releases
+      assert_raises NoMethodError do
+        ProductVersion.new.non_existings
+      end
+    end
+  end
+
+  describe 'has many' do
+    it 'has many association' do
+      releases = ProductVersion.new(product_version_id: 'dp-1').releases.to_a
+      assert_equal 'dp-1.0', releases.first.release_id
+    end
+  end
+
+  describe 'find has many' do
+    it 'find on has many association' do
+      release = ProductVersion.new(product_version_id: 'dp-1').releases.find('dp-1.0')
+      assert_equal 'dp-1.0', release.release_id
+    end
+  end
+
+  describe 'scope' do
+    it 'scopes on associations' do
+      releases = ProductVersion.new(product_version_id: 'dp-1').releases.where(release_id: 'dp-1.0').to_a
+      assert_equal 'dp-1.0', releases.first.release_id
+    end
+  end
+
+  describe 'array like' do
+    it 'array like behavior' do
+      product_version = ProductVersion.new(product_version_id: 'ceph-1')
+      assert_equal %w[ceph-1.3@rhel-7 ceph-1.3-updates@rhel-7], product_version.releases[0..1].map(&:release_id)
+      assert_equal 'ceph-1.3@rhel-7', product_version.releases.first.release_id
+      assert_equal 'ceph-1.3-updates@rhel-7', product_version.releases.last.release_id
+    end
+  end
+
+  describe 'cache' do
+    it 'cached result for associations' do
+      endpoint1 = stub_request(:get, releases_url1)\
+                  .to_return_json('data':
+                                  [{ 'release_id': 'ceph-1.3@rhel-7', 'short': 'ceph',
+                                     'version': '1.3', 'name': 'Red Hat Ceph Storage',
+                                     'base_product': 'rhel-7', 'active': true,
+                                     'product_version': 'ceph-1', 'release_type': 'ga',
+                                     'compose_set': [], 'integrated_with': 'null', 'sigkey': 'null',
+                                     'allow_buildroot_push': true, 'allowed_debuginfo_services': [],
+                                     'allowed_push_targets': [], 'bugzilla': 'null',
+                                     'dist_git': 'null', 'brew': 'null', 'product_pages': 'null',
+                                     'errata': 'null' }])
+      endpoint2 = stub_request(:get, releases_url2)\
+                  .to_return_json('data':
+                                  [{ 'release_id': 'ceph-1.3@rhel-7', 'short': 'ceph',
+                                     'version': '1.3', 'name': 'Red Hat Ceph Storage',
+                                     'base_product': 'rhel-7', 'active': true,
+                                     'product_version': 'ceph-1', 'release_type': 'ga',
+                                     'compose_set': [], 'integrated_with': 'null', 'sigkey': 'null',
+                                     'allow_buildroot_push': true, 'allowed_debuginfo_services': [],
+                                     'allowed_push_targets': [], 'bugzilla': 'null',
+                                     'dist_git': 'null', 'brew': 'null', 'product_pages': 'null',
+                                     'errata': 'null' },
+                                   { 'release_id': 'ceph-1.3-updates@rhel-7', 'short': 'ceph',
+                                     'version': '1.3', 'name': 'Red Hat Ceph Storage',
+                                     'base_product': 'rhel-7', 'active': true,
+                                     'product_version': 'ceph-1', 'release_type': 'updates',
+                                     'compose_set': [], 'integrated_with': 'null', 'sigkey': 'null',
+                                     'allow_buildroot_push': false, 'allowed_debuginfo_services': [],
+                                     'allowed_push_targets': [], 'bugzilla': 'null',
+                                     'dist_git': 'null', 'brew': 'null', 'product_pages': 'null',
+                                     'errata': 'null' }])
+
+      product_version = ProductVersion.new(product_version_id: 'ceph-1')
+      releases = product_version.releases.where(release_id: 'ceph-1.3@rhel-7')
+      releases.any?
+      releases.to_a
+      assert_requested endpoint1, times: 1
+
+      product_version.releases.to_a
+      assert_requested endpoint2, times: 1
+    end
+  end
+
+  describe 'has_one' do
+    it 'has_one assocation' do
+      variant_cpe = ReleaseVariant.new(release: 'dp-1.0', uid: 'Client').variant_cpe
+      assert_equal 'cpe:/asdff', variant_cpe.cpe
+    end
+  end
+end
diff --git a/spec/support/fixtures.rb b/spec/support/fixtures.rb
index 67b6139b1..bd036f32a 100644
--- a/spec/support/fixtures.rb
+++ b/spec/support/fixtures.rb
@@ -28,6 +28,7 @@ class ModelWithIdentity
     include PDC::Resource::Attributes
     include PDC::Resource::Identity
     include PDC::Resource::Scopes
+    include PDC::Resource::Associations
   end
 
   class CustomPrimaryKeyModel
@@ -37,6 +38,7 @@ class CustomPrimaryKeyModel
     include PDC::Resource::Attributes
     include PDC::Resource::Identity
     include PDC::Resource::Scopes
+    include PDC::Resource::Associations
 
     self.primary_key = :foobar
   end
@@ -48,6 +50,7 @@ class ModelBase
     include PDC::Resource::Identity
     include PDC::Resource::Attributes
     include PDC::Resource::Scopes
+    include PDC::Resource::Associations
   end
 
   class Model < ModelBase; end
@@ -60,6 +63,7 @@ class Foobar
       include PDC::Resource::Identity
       include PDC::Resource::Attributes
       include PDC::Resource::Scopes
+      include PDC::Resource::Associations
     end
   end
 end
@@ -114,3 +118,32 @@ class CustomParserModel < Base
     attribute  :age, parser: FixNumParser
   end
 end
+
+module Fixtures
+  class Association < PDC::Base
+    # stub the connection
+    SITE = 'https://pdc.host.dev.eng.pek2.redhat.com/'.freeze
+    self.connection = Faraday.new(url: SITE) do |faraday|
+      faraday.request   :json
+      faraday.use       PDC::Response::Parser
+      faraday.adapter   Faraday.default_adapter
+    end
+  end
+
+  class ProductVersion < Association
+    has_many :releases, uri: 'rest_api/v1/releases/?product_version=:product_version_id'
+  end
+
+  class Release < Association
+    self.primary_key = :release_id
+  end
+
+  class ReleaseVariant < Association
+    has_one :variant_cpe, uri: 'rest_api/v1/variant-cpes/?release=:release&variant_uid=:uid', foreign_key: 'release/variant_uid'
+    self.mapping = { variant_uid: 'uid' }
+  end
+
+  class VariantCpe < Association
+    self.primary_key = :id
+  end
+end