diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 94362bd..7faf289 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -39,6 +39,22 @@ jobs:
           ruby-version: ${{ env.RUBY_VERSION }}
           bundler-cache: true
 
+      - uses: nanasess/setup-chromedriver@v2
+        with:
+          chromedriver-version: 119.0.6045.105
+
+      - name: List Chrome
+        shell: "bash"
+        run: apt list --installed | grep chrome
+
+      - name: Remove Chrome
+        shell: "bash"
+        run: sudo apt remove google-chrome-stable
+
+      - uses: browser-actions/setup-chrome@v1
+        with:
+          chrome-version: 119.0.6045.105
+
       - name: Setup Database
         run: bundle exec rake test_app
     
diff --git a/.rubocop.yml b/.rubocop.yml
index b2dc6b1..748cda2 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1 +1,5 @@
 inherit_from: https://raw.githubusercontent.com/decidim/decidim/release/0.27-stable/.rubocop.yml
+
+RSpec/AnyInstance:
+  Exclude:
+    - 'spec/omni_auth/strategies/civicrm_spec.rb'
\ No newline at end of file
diff --git a/lib/decidim/civicrm/api.rb b/lib/decidim/civicrm/api.rb
index 8965ebe..7df0a5e 100644
--- a/lib/decidim/civicrm/api.rb
+++ b/lib/decidim/civicrm/api.rb
@@ -1,20 +1,48 @@
 # frozen_string_literal: true
 
 require_relative "api/base/base_query"
-require_relative "api/base/find_query"
-require_relative "api/base/list_query"
-require_relative "api/base/request"
+require_relative "api/base/v3/base_query"
+require_relative "api/base/v3/find_query"
+require_relative "api/base/v3/list_query"
+require_relative "api/base/v3/request"
+require_relative "api/base/v4/base_query"
+require_relative "api/base/v4/find_query"
+require_relative "api/base/v4/list_query"
+require_relative "api/base/v4/request"
 require_relative "api/find_contact"
-require_relative "api/find_group"
-require_relative "api/find_user"
 require_relative "api/find_event"
+require_relative "api/find_group"
 require_relative "api/find_participant"
-require_relative "api/participants_in_event"
+require_relative "api/find_user"
 require_relative "api/list_contact_groups"
-require_relative "api/list_contacts_in_group"
 require_relative "api/list_contact_memberships"
+require_relative "api/list_contacts_in_group"
 require_relative "api/list_groups"
 require_relative "api/list_membership_types"
+require_relative "api/participants_in_event"
+require_relative "api/request"
+require_relative "api/v3/find_contact"
+require_relative "api/v3/find_event"
+require_relative "api/v3/find_group"
+require_relative "api/v3/find_participant"
+require_relative "api/v3/find_user"
+require_relative "api/v3/list_contact_groups"
+require_relative "api/v3/list_contact_memberships"
+require_relative "api/v3/list_contacts_in_group"
+require_relative "api/v3/list_groups"
+require_relative "api/v3/list_membership_types"
+require_relative "api/v3/participants_in_event"
+require_relative "api/v4/find_contact"
+require_relative "api/v4/find_event"
+require_relative "api/v4/find_group"
+require_relative "api/v4/find_participant"
+require_relative "api/v4/find_user"
+require_relative "api/v4/list_contact_groups"
+require_relative "api/v4/list_contact_memberships"
+require_relative "api/v4/list_contacts_in_group"
+require_relative "api/v4/list_groups"
+require_relative "api/v4/list_membership_types"
+require_relative "api/v4/participants_in_event"
 
 module Decidim
   module Civicrm
@@ -34,6 +62,17 @@ def self.credentials
       def self.url
         config[:url]
       end
+
+      def self.version
+        config[:version]
+      end
+
+      def self.available_versions
+        @available_versions ||= {
+          v3: "V3",
+          v4: "V4"
+        }
+      end
     end
   end
 end
diff --git a/lib/decidim/civicrm/api/base/base_query.rb b/lib/decidim/civicrm/api/base/base_query.rb
index a23d136..6dacaa9 100644
--- a/lib/decidim/civicrm/api/base/base_query.rb
+++ b/lib/decidim/civicrm/api/base/base_query.rb
@@ -19,12 +19,6 @@ def response
 
           protected
 
-          def json_params(params)
-            params.merge(
-              sequential: 1
-            ).to_json
-          end
-
           def parsed_response
             raise NotImplementedError
           end
@@ -32,13 +26,6 @@ def parsed_response
           def default_query
             raise NotImplementedError
           end
-
-          def store_result
-            return unless success?
-
-            @result = parsed_response
-            @result = @result.deep_symbolize_keys if @result.is_a? Hash
-          end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/base/find_query.rb b/lib/decidim/civicrm/api/base/find_query.rb
deleted file mode 100644
index 82df083..0000000
--- a/lib/decidim/civicrm/api/base/find_query.rb
+++ /dev/null
@@ -1,23 +0,0 @@
-# frozen_string_literal: true
-
-module Decidim
-  module Civicrm
-    module Api
-      module Base
-        class FindQuery < BaseQuery
-          protected
-
-          def json_params(params)
-            params.deep_merge(
-              sequential: 1
-            ).to_json
-          end
-
-          def parsed_response
-            self.class.parse_item(response["values"].first)
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/lib/decidim/civicrm/api/base/list_query.rb b/lib/decidim/civicrm/api/base/list_query.rb
deleted file mode 100644
index 8cbbbc1..0000000
--- a/lib/decidim/civicrm/api/base/list_query.rb
+++ /dev/null
@@ -1,24 +0,0 @@
-# frozen_string_literal: true
-
-module Decidim
-  module Civicrm
-    module Api
-      module Base
-        class ListQuery < BaseQuery
-          protected
-
-          def json_params(params)
-            params.deep_merge(
-              sequential: 1,
-              options: { limit: 0 }
-            ).to_json
-          end
-
-          def parsed_response
-            response["values"].map { |item| self.class.parse_item(item) }
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/lib/decidim/civicrm/api/base/request.rb b/lib/decidim/civicrm/api/base/request.rb
deleted file mode 100644
index 76f7d69..0000000
--- a/lib/decidim/civicrm/api/base/request.rb
+++ /dev/null
@@ -1,53 +0,0 @@
-# frozen_string_literal: true
-
-module Decidim
-  module Civicrm
-    module Api
-      module Base
-        class Request
-          def initialize(verify_ssl: true)
-            @verify_ssl = verify_ssl
-          end
-
-          attr_accessor :response
-
-          def self.get(params, verify_ssl: true)
-            instance = Request.new(verify_ssl: verify_ssl)
-            response = instance.connection.get Decidim::Civicrm::Api.url do |request|
-              request.params = instance.base_params.merge(params)
-
-              # puts [request.path, URI.encode_www_form(request.params.sort)].join("/?") # DEBUG, to obtain the correct URL for stub_request
-            end
-
-            raise Decidim::Civicrm::Error, response.reason_phrase unless response.success?
-
-            instance.response = JSON.parse(response.body).to_h
-            instance
-          end
-
-          def self.post(params, verify_ssl: true)
-            instance = Request.new(verify_ssl: verify_ssl)
-            response = instance.connection.post Decidim::Civicrm::Api.url do |request|
-              request.params = instance.base_params.merge(params)
-            end
-
-            raise Decidim::Civicrm::Error, response.reason_phrase unless response.success?
-
-            instance.response = JSON.parse(response.body).to_h
-            instance
-          end
-
-          def connection
-            @connection ||= Faraday.new(ssl: { verify: @verify_ssl })
-          end
-
-          def base_params
-            Decidim::Civicrm::Api.credentials.merge(
-              action: "Get"
-            )
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/lib/decidim/civicrm/api/base/v3/base_query.rb b/lib/decidim/civicrm/api/base/v3/base_query.rb
new file mode 100644
index 0000000..c12bdce
--- /dev/null
+++ b/lib/decidim/civicrm/api/base/v3/base_query.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module Base
+        module V3
+          class BaseQuery < Base::BaseQuery
+            attr_reader :result, :request
+
+            protected
+
+            def json_params(params)
+              params.merge(
+                sequential: 1
+              ).to_json
+            end
+
+            def store_result
+              return unless success?
+
+              @result = parsed_response
+              @result = @result.deep_symbolize_keys if @result.is_a? Hash
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/base/v3/find_query.rb b/lib/decidim/civicrm/api/base/v3/find_query.rb
new file mode 100644
index 0000000..be93e6b
--- /dev/null
+++ b/lib/decidim/civicrm/api/base/v3/find_query.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module Base
+        module V3
+          class FindQuery < BaseQuery
+            protected
+
+            def json_params(params)
+              params.deep_merge(
+                sequential: 1
+              ).to_json
+            end
+
+            def parsed_response
+              self.class.parse_item(response["values"].first)
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/base/v3/list_query.rb b/lib/decidim/civicrm/api/base/v3/list_query.rb
new file mode 100644
index 0000000..3ae68a9
--- /dev/null
+++ b/lib/decidim/civicrm/api/base/v3/list_query.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module Base
+        module V3
+          class ListQuery < BaseQuery
+            protected
+
+            def json_params(params)
+              params.deep_merge(
+                sequential: 1,
+                options: { limit: 0 }
+              ).to_json
+            end
+
+            def parsed_response
+              response["values"].map { |item| self.class.parse_item(item) }
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/base/v3/request.rb b/lib/decidim/civicrm/api/base/v3/request.rb
new file mode 100644
index 0000000..cc34d45
--- /dev/null
+++ b/lib/decidim/civicrm/api/base/v3/request.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module Base
+        module V3
+          class Request
+            def initialize(verify_ssl: true)
+              @verify_ssl = verify_ssl
+            end
+
+            attr_accessor :response
+
+            def self.get(params, verify_ssl: true)
+              instance = Request.new(verify_ssl: verify_ssl)
+              response = instance.connection.get Decidim::Civicrm::Api.url do |request|
+                request.params = instance.base_params.merge(params)
+                # puts [request.path, URI.encode_www_form(request.params.sort)].join("/?") # DEBUG, to obtain the correct URL for stub_request
+              end
+
+              raise Decidim::Civicrm::Error, response.reason_phrase unless response.success?
+
+              instance.response = JSON.parse(response.body).to_h
+              instance
+            end
+
+            def self.post(params, verify_ssl: true)
+              instance = Request.new(verify_ssl: verify_ssl)
+              response = instance.connection.post Decidim::Civicrm::Api.url do |request|
+                request.params = instance.base_params.merge(params)
+              end
+
+              raise Decidim::Civicrm::Error, response.reason_phrase unless response.success?
+
+              instance.response = JSON.parse(response.body).to_h
+              instance
+            end
+
+            def connection
+              @connection ||= Faraday.new(ssl: { verify: @verify_ssl })
+            end
+
+            def base_params
+              Decidim::Civicrm::Api.credentials.merge(
+                action: "Get"
+              )
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/base/v4/base_query.rb b/lib/decidim/civicrm/api/base/v4/base_query.rb
new file mode 100644
index 0000000..56a2ca4
--- /dev/null
+++ b/lib/decidim/civicrm/api/base/v4/base_query.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module Base
+        module V4
+          class BaseQuery < Base::BaseQuery
+            attr_reader :result, :request
+
+            def store_result
+              return unless success?
+
+              @result = parsed_response
+              @result[:values] = @result[:values].deep_symbolize_keys if @result[:values].is_a? Hash
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/base/v4/find_query.rb b/lib/decidim/civicrm/api/base/v4/find_query.rb
new file mode 100644
index 0000000..de8495c
--- /dev/null
+++ b/lib/decidim/civicrm/api/base/v4/find_query.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module Base
+        module V4
+          class FindQuery < BaseQuery
+            protected
+
+            def parsed_response
+              self.class.parse_item(response["values"].first)
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/base/v4/list_query.rb b/lib/decidim/civicrm/api/base/v4/list_query.rb
new file mode 100644
index 0000000..1727a48
--- /dev/null
+++ b/lib/decidim/civicrm/api/base/v4/list_query.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module Base
+        module V4
+          class ListQuery < BaseQuery
+            protected
+
+            def initialize(id = nil, query = nil)
+              results = []
+              offset = 0
+              @id = id
+              @request = request(offset, query)
+
+              store_result
+              results << @result[:values]
+              offset += self.class.records_by_page
+              while offset < @result[:count_matched]
+                @request = request(offset, query)
+
+                store_result
+                results << @result[:values]
+                offset += self.class.records_by_page
+              end
+              @result = results.flatten
+            end
+
+            def parsed_response
+              {
+                count_matched: response["countMatched"],
+                values: response["values"].map { |item| self.class.parse_item(item) }
+              }
+            end
+
+            class << self
+              def records_by_page
+                200
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/base/v4/request.rb b/lib/decidim/civicrm/api/base/v4/request.rb
new file mode 100644
index 0000000..996f84a
--- /dev/null
+++ b/lib/decidim/civicrm/api/base/v4/request.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module Base
+        module V4
+          class Request
+            def initialize(verify_ssl: true)
+              @verify_ssl = verify_ssl
+            end
+
+            attr_accessor :response
+
+            def self.get(entity, params, action, verify_ssl: true)
+              instance = Request.new(verify_ssl: verify_ssl)
+              url = "#{Decidim::Civicrm::Api.url}/#{entity}/#{action}"
+              response = instance.connection.get url do |request|
+                request.params = {
+                  "_authx" => auth_token,
+                  "params" => params.to_json
+                }
+              end
+              raise Decidim::Civicrm::Error, response.reason_phrase unless response.success?
+
+              instance.response = JSON.parse(response.body).to_h
+              instance
+            end
+
+            def self.post(entity, params, action, verify_ssl: true)
+              instance = Request.new(verify_ssl: verify_ssl)
+              url = "#{Decidim::Civicrm::Api.url}/#{entity}/#{action}"
+
+              response = instance.connection.post url do |request|
+                request.params = if action == "get"
+                                   { "params" => params.to_json }
+                                 else
+                                   params
+                                 end
+                request.headers["X-Civi-Auth"] = auth_token
+              end
+              raise Decidim::Civicrm::Error, response.reason_phrase unless response.success?
+
+              instance.response = JSON.parse(response.body).to_h
+              instance
+            end
+
+            def connection
+              @connection ||= Faraday.new(ssl: { verify: @verify_ssl })
+            end
+
+            def self.auth_token
+              "Bearer #{Decidim::Civicrm::Api.credentials[:api_key]}"
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/find_contact.rb b/lib/decidim/civicrm/api/find_contact.rb
index 3f45c15..e731794 100644
--- a/lib/decidim/civicrm/api/find_contact.rb
+++ b/lib/decidim/civicrm/api/find_contact.rb
@@ -3,40 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class FindContact < Base::FindQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "Contact",
-              contact_id: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
-
-        def default_query
-          {
-            return: "display_name",
-            "api.Membership.get" => {
-              return: "membership_type_id"
-            }
-          }
-        end
-
-        def self.parse_item(item)
-          contact = {
-            id: item["id"].to_i,
-            display_name: item["display_name"]
-          }
+      class FindContact
+        attr_reader :result
 
-          memberships = item["api.Membership.get"]["values"]
-
-          {
-            contact: contact,
-            memberships: memberships.map { |m| ListContactMemberships.parse_item(m) }
-          }
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::FindContact.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::FindContact.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/find_event.rb b/lib/decidim/civicrm/api/find_event.rb
index 42eddf6..d04d100 100644
--- a/lib/decidim/civicrm/api/find_event.rb
+++ b/lib/decidim/civicrm/api/find_event.rb
@@ -3,31 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class FindEvent < Base::FindQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "Event",
-              id: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class FindEvent
+        attr_reader :result
 
-        def default_query
-          {
-            return: "event_id,title,event_title,event_type,start_date,evet_start_date,end_date,event_end_date"
-          }
-        end
-
-        private
-
-        def parsed_response
-          {
-            event: response["values"].first
-          }
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::FindEvent.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::FindEvent.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/find_group.rb b/lib/decidim/civicrm/api/find_group.rb
index f768113..ce12371 100644
--- a/lib/decidim/civicrm/api/find_group.rb
+++ b/lib/decidim/civicrm/api/find_group.rb
@@ -3,33 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class FindGroup < Base::FindQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "Group",
-              group_id: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class FindGroup
+        attr_reader :result
 
-        def default_query
-          {
-            return: "group_id,name,title,description,group_type"
-          }
-        end
-
-        def self.parse_item(item)
-          {
-            id: item["id"].to_i,
-            name: item["name"],
-            title: item["title"],
-            description: item["description"],
-            group_type: item["group_type"].respond_to?(:map) ? item["group_type"].map(&:to_i) : [item["group_type"].to_i]
-          }
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::FindGroup.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::FindGroup.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/find_participant.rb b/lib/decidim/civicrm/api/find_participant.rb
index 2dc1af5..c84dc84 100644
--- a/lib/decidim/civicrm/api/find_participant.rb
+++ b/lib/decidim/civicrm/api/find_participant.rb
@@ -3,31 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class FindParticipant < Base::FindQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "Participant",
-              id: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class FindParticipant
+        attr_reader :result
 
-        def default_query
-          {
-            return: "contact_id,display_name,participant_status,id,participant_fee_amount,participant_fee_level,participant_fee_currency"
-          }
-        end
-
-        private
-
-        def parsed_response
-          {
-            participant: response["values"].first
-          }
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::FindParticipant.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::FindParticipant.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/find_user.rb b/lib/decidim/civicrm/api/find_user.rb
index 95b01f4..45796e1 100644
--- a/lib/decidim/civicrm/api/find_user.rb
+++ b/lib/decidim/civicrm/api/find_user.rb
@@ -3,49 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class FindUser < Base::FindQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "User",
-              id: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class FindUser
+        attr_reader :result
 
-        def default_query
-          {
-            "api.Contact.get" => {
-              return: "display_name"
-            },
-            "api.Membership.get": {
-              contact_id: "$value.contact_id",
-              return: "membership_type_id"
-            }
-          }
-        end
-
-        def self.parse_item(item)
-          user = item
-          contact = user.delete("api.Contact.get")["values"].first
-          memberships = user.delete("api.Membership.get")["values"]
-
-          {
-            user: {
-              id: user["id"].to_i,
-              name: user["name"],
-              email: user["email"],
-              contact_id: user["contact_id"].to_i
-            },
-            contact: {
-              id: user["contact_id"].to_i,
-              display_name: contact["display_name"]
-            },
-            memberships: memberships.map { |m| ListContactMemberships.parse_item(m) }
-          }
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::FindUser.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::FindUser.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/list_contact_groups.rb b/lib/decidim/civicrm/api/list_contact_groups.rb
index 7a828d0..051f868 100644
--- a/lib/decidim/civicrm/api/list_contact_groups.rb
+++ b/lib/decidim/civicrm/api/list_contact_groups.rb
@@ -3,27 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class ListContactGroups < Base::ListQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "GroupContact",
-              contact_id: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class ListContactGroups
+        attr_reader :result
 
-        def default_query
-          {
-            return: "group_id"
-          }
-        end
-
-        def self.parse_item(item)
-          item["group_id"].to_i
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::ListContactGroups.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::ListContactGroups.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/list_contact_memberships.rb b/lib/decidim/civicrm/api/list_contact_memberships.rb
index 72104f9..bdd4e0f 100644
--- a/lib/decidim/civicrm/api/list_contact_memberships.rb
+++ b/lib/decidim/civicrm/api/list_contact_memberships.rb
@@ -3,27 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class ListContactMemberships < Base::ListQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "Membership",
-              contact_id: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class ListContactMemberships
+        attr_reader :result
 
-        def default_query
-          {
-            return: "membership_type_id"
-          }
-        end
-
-        def self.parse_item(item)
-          item["membership_type_id"].to_i
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::ListContactMemberships.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::ListContactMemberships.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/list_contacts_in_group.rb b/lib/decidim/civicrm/api/list_contacts_in_group.rb
index 20f1210..0785f03 100644
--- a/lib/decidim/civicrm/api/list_contacts_in_group.rb
+++ b/lib/decidim/civicrm/api/list_contacts_in_group.rb
@@ -3,30 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class ListContactsInGroup < Base::ListQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "Contact",
-              group: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class ListContactsInGroup
+        attr_reader :result
 
-        def default_query
-          {
-            return: "contact_id,display_name"
-          }
-        end
-
-        def self.parse_item(item)
-          {
-            contact_id: item["contact_id"].to_i,
-            display_name: item["display_name"]
-          }
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::ListContactsInGroup.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::ListContactsInGroup.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/list_groups.rb b/lib/decidim/civicrm/api/list_groups.rb
index fba9f90..ae48a39 100644
--- a/lib/decidim/civicrm/api/list_groups.rb
+++ b/lib/decidim/civicrm/api/list_groups.rb
@@ -3,27 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class ListGroups < Base::ListQuery
-        def initialize(query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "Group",
-              is_active: 1,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class ListGroups
+        attr_reader :result
 
-        def default_query
-          {
-            return: "group_id,name,title,description,group_type"
-          }
-        end
-
-        def self.parse_item(item)
-          FindGroup.parse_item(item)
+        def initialize(query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::ListGroups.new(query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::ListGroups.new(query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/list_membership_types.rb b/lib/decidim/civicrm/api/list_membership_types.rb
index a90b127..b76c9ed 100644
--- a/lib/decidim/civicrm/api/list_membership_types.rb
+++ b/lib/decidim/civicrm/api/list_membership_types.rb
@@ -3,29 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class ListMembershipTypes < Base::ListQuery
-        def initialize(query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "MembershipType",
-              json: json_params(query || default_query)
-            }
-          )
-          store_result
-        end
+      class ListMembershipTypes
+        attr_reader :result
 
-        def default_query
-          {
-            options: { limit: 0 },
-            return: "name"
-          }
-        end
-
-        def self.parse_item(item)
-          {
-            id: item["id"].to_i,
-            name: item["name"]
-          }
+        def initialize(query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::ListMembershipTypes.new(query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::ListMembershipTypes.new(query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/participants_in_event.rb b/lib/decidim/civicrm/api/participants_in_event.rb
index 9884f6c..107c229 100644
--- a/lib/decidim/civicrm/api/participants_in_event.rb
+++ b/lib/decidim/civicrm/api/participants_in_event.rb
@@ -3,30 +3,16 @@
 module Decidim
   module Civicrm
     module Api
-      class ParticipantsInEvent < Base::ListQuery
-        def initialize(id, query = nil)
-          @request = Base::Request.get(
-            {
-              entity: "Participant",
-              event_id: id,
-              json: json_params(query || default_query)
-            }
-          )
-
-          store_result
-        end
+      class ParticipantsInEvent
+        attr_reader :result
 
-        def default_query
-          {
-            options: { limit: 0 },
-            return: "contact_id,display_name,participant_status,id,participant_fee_amount,participant_fee_level,participant_fee_currency"
-          }
-        end
-
-        private
-
-        def parsed_response
-          response["values"]
+        def initialize(id, query = nil)
+          @result = case Decidim::Civicrm::Api.version
+                    when Decidim::Civicrm::Api.available_versions[:v3]
+                      Decidim::Civicrm::Api::V3::ParticipantsInEvent.new(id, query).result
+                    when Decidim::Civicrm::Api.available_versions[:v4]
+                      Decidim::Civicrm::Api::V4::ParticipantsInEvent.new(id, query).result
+                    end
         end
       end
     end
diff --git a/lib/decidim/civicrm/api/request.rb b/lib/decidim/civicrm/api/request.rb
new file mode 100644
index 0000000..4fed043
--- /dev/null
+++ b/lib/decidim/civicrm/api/request.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      class Request
+        def self.post(data)
+          case Decidim::Civicrm::Api.version
+          when Decidim::Civicrm::Api.available_versions[:v3]
+            Decidim::Civicrm::Api::Base::V3::Request.post(data, verify_ssl: true)
+          when Decidim::Civicrm::Api.available_versions[:v4]
+            entity = data[:entity]
+            action = data[:action]
+            data.delete(:entity)
+            data.delete(:action)
+            data.delete(:json)
+            Decidim::Civicrm::Api::Base::V4::Request.post(entity, data, action, verify_ssl: true)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/find_contact.rb b/lib/decidim/civicrm/api/v3/find_contact.rb
new file mode 100644
index 0000000..713f26c
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/find_contact.rb
@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class FindContact < Base::V3::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "Contact",
+                contact_id: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              return: "display_name",
+              "api.Membership.get" => {
+                return: "membership_type_id"
+              }
+            }
+          end
+
+          def self.parse_item(item)
+            contact = {
+              id: item["id"].to_i,
+              display_name: item["display_name"]
+            }
+
+            memberships = item["api.Membership.get"]["values"]
+
+            {
+              contact: contact,
+              memberships: memberships.map { |m| ListContactMemberships.parse_item(m) }
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/find_event.rb b/lib/decidim/civicrm/api/v3/find_event.rb
new file mode 100644
index 0000000..107139a
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/find_event.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class FindEvent < Base::V3::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "Event",
+                id: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              return: "event_id,title,event_title,event_type,start_date,event_start_date,end_date,event_end_date"
+            }
+          end
+
+          private
+
+          def parsed_response
+            {
+              event: response["values"].first
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/find_group.rb b/lib/decidim/civicrm/api/v3/find_group.rb
new file mode 100644
index 0000000..dae356b
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/find_group.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class FindGroup < Base::V3::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "Group",
+                group_id: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              return: "group_id,name,title,description,group_type"
+            }
+          end
+
+          def self.parse_item(item)
+            {
+              id: item["id"].to_i,
+              name: item["name"],
+              title: item["title"],
+              description: item["description"],
+              group_type: item["group_type"].respond_to?(:map) ? item["group_type"].map(&:to_i) : [item["group_type"].to_i]
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/find_participant.rb b/lib/decidim/civicrm/api/v3/find_participant.rb
new file mode 100644
index 0000000..929f23c
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/find_participant.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class FindParticipant < Base::V3::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "Participant",
+                id: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              return: "contact_id,display_name,participant_status,id,participant_fee_amount,participant_fee_level,participant_fee_currency"
+            }
+          end
+
+          private
+
+          def parsed_response
+            {
+              participant: response["values"].first
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/find_user.rb b/lib/decidim/civicrm/api/v3/find_user.rb
new file mode 100644
index 0000000..9f8b57f
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/find_user.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class FindUser < Base::V3::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "User",
+                id: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              "api.Contact.get" => {
+                return: "display_name"
+              },
+              "api.Membership.get": {
+                contact_id: "$value.contact_id",
+                return: "membership_type_id"
+              }
+            }
+          end
+
+          def self.parse_item(item)
+            user = item
+            contact = user.delete("api.Contact.get")["values"].first
+            memberships = user.delete("api.Membership.get")["values"]
+
+            {
+              user: {
+                id: user["id"].to_i,
+                name: user["name"],
+                email: user["email"],
+                contact_id: user["contact_id"].to_i
+              },
+              contact: {
+                id: user["contact_id"].to_i,
+                display_name: contact["display_name"]
+              },
+              memberships: memberships.map { |m| ListContactMemberships.parse_item(m) }
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/list_contact_groups.rb b/lib/decidim/civicrm/api/v3/list_contact_groups.rb
new file mode 100644
index 0000000..0ddac20
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/list_contact_groups.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class ListContactGroups < Base::V3::ListQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "GroupContact",
+                contact_id: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              select: "group_id"
+            }
+          end
+
+          def self.parse_item(item)
+            item["group_id"].to_i
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/list_contact_memberships.rb b/lib/decidim/civicrm/api/v3/list_contact_memberships.rb
new file mode 100644
index 0000000..644362b
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/list_contact_memberships.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class ListContactMemberships < Base::V3::ListQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "Membership",
+                contact_id: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              return: "membership_type_id"
+            }
+          end
+
+          def self.parse_item(item)
+            item["membership_type_id"].to_i
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/list_contacts_in_group.rb b/lib/decidim/civicrm/api/v3/list_contacts_in_group.rb
new file mode 100644
index 0000000..09b4baa
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/list_contacts_in_group.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class ListContactsInGroup < Base::V3::ListQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "Contact",
+                group: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              return: "contact_id,display_name"
+            }
+          end
+
+          def self.parse_item(item)
+            {
+              contact_id: item["contact_id"].to_i,
+              display_name: item["display_name"]
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/list_groups.rb b/lib/decidim/civicrm/api/v3/list_groups.rb
new file mode 100644
index 0000000..fc0411a
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/list_groups.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class ListGroups < Base::V3::ListQuery
+          def initialize(query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "Group",
+                is_active: 1, # esto sigue existiendo?
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              return: "group_id,name,title,description,group_type"
+            }
+          end
+
+          def self.parse_item(item)
+            FindGroup.parse_item(item)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/list_membership_types.rb b/lib/decidim/civicrm/api/v3/list_membership_types.rb
new file mode 100644
index 0000000..be4444d
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/list_membership_types.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class ListMembershipTypes < Base::V3::ListQuery
+          def initialize(query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "MembershipType",
+                json: json_params(query || default_query)
+              }
+            )
+            store_result
+          end
+
+          def default_query
+            {
+              options: { limit: 0 },
+              return: "name"
+            }
+          end
+
+          def self.parse_item(item)
+            {
+              id: item["id"].to_i,
+              name: item["name"]
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v3/participants_in_event.rb b/lib/decidim/civicrm/api/v3/participants_in_event.rb
new file mode 100644
index 0000000..e783cad
--- /dev/null
+++ b/lib/decidim/civicrm/api/v3/participants_in_event.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V3
+        class ParticipantsInEvent < Base::V3::ListQuery
+          def initialize(id, query = nil)
+            @request = Base::V3::Request.get(
+              {
+                entity: "Participant",
+                event_id: id,
+                json: json_params(query || default_query)
+              }
+            )
+
+            store_result
+          end
+
+          def default_query
+            {
+              options: { limit: 0 },
+              return: "contact_id,display_name,participant_status,id,participant_fee_amount,participant_fee_level,participant_fee_currency"
+            }
+          end
+
+          private
+
+          def parsed_response
+            response["values"]
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/find_contact.rb b/lib/decidim/civicrm/api/v4/find_contact.rb
new file mode 100644
index 0000000..2c362a9
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/find_contact.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class FindContact < Base::V4::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V4::Request.post(
+              "Contact",
+              query || default_query(id),
+              "get"
+            )
+
+            store_result
+          end
+
+          def default_query(id)
+            {
+              select: %w(id membership.membership_type_id display_name),
+              join: [["Membership AS membership", "LEFT"]],
+              where: [["id", "=", id]]
+            }
+          end
+
+          def self.parse_item(item)
+            contact = {
+              id: item["id"],
+              display_name: item["display_name"]
+            }
+
+            {
+              contact: contact,
+              memberships: Array(item["membership.membership_type_id"])
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/find_event.rb b/lib/decidim/civicrm/api/v4/find_event.rb
new file mode 100644
index 0000000..30e3824
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/find_event.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class FindEvent < Base::V4::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V4::Request.post(
+              "Event",
+              query || default_query(id),
+              "get"
+            )
+
+            store_result
+          end
+
+          def default_query(id)
+            {
+              select: %w(event_id title event_title event_type start_date event_start_date end_date event_end_date),
+              where: [["id", "=", id]]
+            }
+          end
+
+          private
+
+          def parsed_response
+            response_hash = response["values"].first
+            if response_hash
+              response_hash["event_title"] = response_hash["title"]
+              response_hash["event_start_date"] = response_hash["start_date"]
+              response_hash["event_end_date"] = response_hash["end_date"]
+            end
+            {
+              event: response_hash
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/find_group.rb b/lib/decidim/civicrm/api/v4/find_group.rb
new file mode 100644
index 0000000..5331105
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/find_group.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class FindGroup < Base::V4::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V4::Request.post(
+              "Group",
+              query || default_query(id),
+              "get"
+            )
+
+            store_result
+          end
+
+          def default_query(id)
+            {
+              select: %w(group_id name title description group_type),
+              where: [["id", "=", id]]
+            }
+          end
+
+          def self.parse_item(item)
+            {
+              id: item["id"].to_i,
+              name: item["name"],
+              title: item["title"],
+              description: item["description"],
+              group_type: item["group_type"].respond_to?(:map) ? item["group_type"].map(&:to_i) : [item["group_type"].to_i]
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/find_participant.rb b/lib/decidim/civicrm/api/v4/find_participant.rb
new file mode 100644
index 0000000..c067408
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/find_participant.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class FindParticipant < Base::V4::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V4::Request.post(
+              "Participant",
+              query || default_query(id),
+              "get"
+            )
+
+            store_result
+          end
+
+          def default_query(id)
+            {
+              select: %w(contact_id contact_id.display_name status_id:label id fee_amount fee_level fee_currency),
+              where: [["id", "=", id]]
+            }
+          end
+
+          private
+
+          def parsed_response
+            response_hash = response["values"].first
+            if response_hash
+              response_hash["display_name"] = response_hash.delete("contact_id.display_name")
+              response_hash["participant_status"] = response_hash.delete("status_id:label")
+              response_hash["participant_fee_level"] = response_hash.delete("fee_level")
+              response_hash["participant_fee_amount"] = response_hash.delete("fee_amount")
+              response_hash["participant_fee_currency"] = response_hash.delete("fee_currency")
+              response_hash["participant_id"] = response_hash["id"]
+            end
+            {
+              participant: response_hash
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/find_user.rb b/lib/decidim/civicrm/api/v4/find_user.rb
new file mode 100644
index 0000000..a2a0536
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/find_user.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class FindUser < Base::V4::FindQuery
+          def initialize(id, query = nil)
+            @request = Base::V4::Request.post(
+              "Contact",
+              query || default_query(id),
+              "get"
+            )
+
+            store_result
+          end
+
+          def default_query(id)
+            {
+              select: %w(uf_match.uf_id uf_match.contact_id display_name email_primary.email membership.membership_type_id:label),
+              join: [["UFMatch AS uf_match", "LEFT"], ["Membership AS membership", "LEFT"]],
+              where: [["uf_match.uf_id", "=", id]]
+            }
+          end
+
+          def self.parse_item(item)
+            {
+              user: {
+                id: item["id"],
+                name: item["name"],
+                email: item["email_primary.email"],
+                contact_id: item["uf_match.contact_id"]
+              },
+              contact: {
+                id: item["uf_match.contact_id"],
+                display_name: item["display_name"]
+              },
+              memberships: Array(item["membership.membership_type_id:label"])
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/list_contact_groups.rb b/lib/decidim/civicrm/api/v4/list_contact_groups.rb
new file mode 100644
index 0000000..fb8de8d
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/list_contact_groups.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class ListContactGroups < Base::V4::ListQuery
+          def request(offset, query = nil)
+            Base::V4::Request.post(
+              "GroupContact",
+              query || default_query(offset),
+              "get"
+            )
+          end
+
+          def default_query(offset)
+            {
+              select: %w(row_count group_id),
+              where: [["contact_id", "=", @id]],
+              offset: offset
+            }
+          end
+
+          def self.parse_item(item)
+            item["group_id"].to_i
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/list_contact_memberships.rb b/lib/decidim/civicrm/api/v4/list_contact_memberships.rb
new file mode 100644
index 0000000..600fa19
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/list_contact_memberships.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class ListContactMemberships < Base::V4::ListQuery
+          def request(offset, query = nil)
+            Base::V4::Request.post(
+              "Membership",
+              query || default_query(offset),
+              "get"
+            )
+          end
+
+          def default_query(offset)
+            {
+              select: %w(row_count membership_type_id),
+              where: [["contact_id", "=", @id]],
+              offset: offset
+            }
+          end
+
+          def self.parse_item(item)
+            item["membership_type_id"].to_i
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/list_contacts_in_group.rb b/lib/decidim/civicrm/api/v4/list_contacts_in_group.rb
new file mode 100644
index 0000000..914185c
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/list_contacts_in_group.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class ListContactsInGroup < Base::V4::ListQuery
+          def request(offset, query = nil)
+            Base::V4::Request.post(
+              "Contact",
+              query || default_query(offset),
+              "get"
+            )
+          end
+
+          def default_query(offset)
+            {
+              select: %w(row_count contact_id display_name),
+              offset: offset,
+              where: [["groups", "IN", @id]]
+            }
+          end
+
+          def self.parse_item(item)
+            {
+              contact_id: item["id"],
+              display_name: item["display_name"]
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/list_groups.rb b/lib/decidim/civicrm/api/v4/list_groups.rb
new file mode 100644
index 0000000..9d15955
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/list_groups.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class ListGroups < Base::V4::ListQuery
+          def request(offset, query = nil)
+            Base::V4::Request.post(
+              "Group",
+              query || default_query(offset),
+              "get"
+            )
+          end
+
+          def default_query(offset)
+            {
+              select: %w(row_count group_id name title description group_type),
+              offset: offset
+            }
+          end
+
+          def self.parse_item(item)
+            FindGroup.parse_item(item)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/list_membership_types.rb b/lib/decidim/civicrm/api/v4/list_membership_types.rb
new file mode 100644
index 0000000..97a6a6e
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/list_membership_types.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class ListMembershipTypes < Base::V4::ListQuery
+          def request(offset, query = nil)
+            Base::V4::Request.post(
+              "MembershipType",
+              query || default_query(offset),
+              "get"
+            )
+          end
+
+          def default_query(offset)
+            {
+              select: %w(row_count name),
+              offset: offset
+            }
+          end
+
+          def self.parse_item(item)
+            {
+              id: item["id"].to_i,
+              name: item["name"]
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/api/v4/participants_in_event.rb b/lib/decidim/civicrm/api/v4/participants_in_event.rb
new file mode 100644
index 0000000..a32cb72
--- /dev/null
+++ b/lib/decidim/civicrm/api/v4/participants_in_event.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Civicrm
+    module Api
+      module V4
+        class ParticipantsInEvent < Base::V4::ListQuery
+          def request(offset, query = nil)
+            Base::V4::Request.post(
+              "Participant",
+              query || default_query(offset),
+              "get"
+            )
+          end
+
+          def default_query(offset)
+            {
+              select: %w(row_count id contact_id contact_id.display_name status_id:name fee_amount fee_level fee_currency),
+              offset: offset,
+              where: [["event_id", "=", @id]]
+            }
+          end
+
+          def self.parse_item(item)
+            {
+              contact_id: item["contact_id"].to_s,
+              display_name: item["contact_id.display_name"],
+              participant_id: item["id"].to_s,
+              participant_fee_level: item["fee_level"],
+              participant_fee_amount: item["fee_amount"],
+              participant_fee_currency: item["fee_currency"],
+              participant_status: item["status_id:name"],
+              id: item["id"].to_s
+            }
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/decidim/civicrm/test/shared_contexts.rb b/lib/decidim/civicrm/test/v3/shared_contexts.rb
similarity index 76%
rename from lib/decidim/civicrm/test/shared_contexts.rb
rename to lib/decidim/civicrm/test/v3/shared_contexts.rb
index ebe35c0..cfb8dd4 100644
--- a/lib/decidim/civicrm/test/shared_contexts.rb
+++ b/lib/decidim/civicrm/test/v3/shared_contexts.rb
@@ -2,8 +2,8 @@
 
 shared_context "with stubs example api" do
   let(:url) { "https://api.example.org/" }
-  let(:http_method) { :get }
   let(:http_status) { 200 }
+  let(:http_method) { :any }
   let(:data) do
     {
       "values" => [],
@@ -17,6 +17,7 @@
   end
 
   before do
+    Decidim::Civicrm::Api.config[:version] = Decidim::Civicrm::Api.available_versions[:v3]
     allow(Decidim::Civicrm::Api).to receive(:url).and_return(url)
     stub_request(http_method, /api\.example\.org/)
       .to_return(status: http_status, body: data.to_json, headers: {})
@@ -24,6 +25,9 @@
 end
 
 shared_examples "returns mapped array ids" do |property|
+  before do
+    Decidim::Civicrm::Api.config[:version] = Decidim::Civicrm::Api.available_versions[:v3]
+  end
   it "returns an Array with the result" do
     expect(subject.result).to be_a Array
     expect(subject.result).to eq(data["values"].map { |v| v[property].to_i })
diff --git a/lib/decidim/civicrm/test/v4/shared_contexts.rb b/lib/decidim/civicrm/test/v4/shared_contexts.rb
new file mode 100644
index 0000000..54d13d5
--- /dev/null
+++ b/lib/decidim/civicrm/test/v4/shared_contexts.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+shared_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}" do
+  let(:url) { "https://api.example.org/" }
+  let(:http_status) { 200 }
+  let(:http_method) { :any }
+  let(:data) do
+    {
+      "values" => [],
+      "entity" => "",
+      "action" => "",
+      "version" => 4,
+      "count" => 0,
+      "countFetched" => 0,
+      "countMatched" => 0
+    }
+  end
+  let(:params) do
+    {}
+  end
+
+  let(:entity) { "" }
+  let(:action) { "" }
+
+  before do
+    Decidim::Civicrm::Api.config[:version] = Decidim::Civicrm::Api.available_versions[:v4]
+    allow(Decidim::Civicrm::Api).to receive(:url).and_return(url)
+    stub_request(http_method, /api\.example\.org/)
+      .to_return(status: http_status, body: data.to_json, headers: {})
+  end
+end
+
+shared_examples "returns mapped array ids #{Decidim::Civicrm::Api.available_versions[:v4]}" do |property|
+  before do
+    Decidim::Civicrm::Api.config[:version] = Decidim::Civicrm::Api.available_versions[:v4]
+  end
+  it "returns an Array with the result" do
+    expect(subject.result).to be_a Array
+    expect(subject.result).to eq(data["values"].map { |v| v[property].to_i })
+  end
+end
diff --git a/lib/generators/decidim/civicrm/templates/development_civicrm_config.rb b/lib/generators/decidim/civicrm/templates/development_civicrm_config.rb
index 4c615dc..fad1146 100644
--- a/lib/generators/decidim/civicrm/templates/development_civicrm_config.rb
+++ b/lib/generators/decidim/civicrm/templates/development_civicrm_config.rb
@@ -6,7 +6,8 @@
   config.api = {
     key: ENV.fetch("CIVICRM_VERIFICATION_API_KEY", nil),
     secret: ENV.fetch("CIVICRM_VERIFICATION_SECRET", nil),
-    url: ENV.fetch("CIVICRM_VERIFICATION_URL", nil)
+    url: ENV.fetch("CIVICRM_VERIFICATION_URL", nil),
+    version: ENV.fetch("CIVICRM_API_VERSION", nil)
   }
 
   # Configure omniauth secrets
diff --git a/lib/omniauth/strategies/civicrm.rb b/lib/omniauth/strategies/civicrm.rb
index 734791a..9ee8935 100644
--- a/lib/omniauth/strategies/civicrm.rb
+++ b/lib/omniauth/strategies/civicrm.rb
@@ -20,8 +20,8 @@ class Civicrm < OmniAuth::Strategies::OAuth2
 
       info do
         {
-          name: extra[:contact][:display_name],
-          nickname: raw_info["preferred_username"],
+          name: parsed_name,
+          nickname: parsed_nickname,
           email: raw_info["email"],
           image: raw_info["picture"]
         }
@@ -55,6 +55,14 @@ def raw_info
       def civicrm_info
         @civicrm_info ||= ::Decidim::Civicrm::Api::FindUser.new(uid).result
       end
+
+      def parsed_name
+        extra[:contact][:display_name].gsub(/[<>?%&^*#@()\[\]=+:;"{}\\|]/, "")
+      end
+
+      def parsed_nickname
+        ::Decidim::UserBaseEntity.nicknamize(raw_info["preferred_username"])
+      end
     end
   end
 end
diff --git a/spec/fixtures/files/empty_response.json b/spec/fixtures/files/v3/empty_response.json
similarity index 100%
rename from spec/fixtures/files/empty_response.json
rename to spec/fixtures/files/v3/empty_response.json
diff --git a/spec/fixtures/files/error_response.json b/spec/fixtures/files/v3/error_response.json
similarity index 100%
rename from spec/fixtures/files/error_response.json
rename to spec/fixtures/files/v3/error_response.json
diff --git a/spec/fixtures/files/event_valid_response.json b/spec/fixtures/files/v3/event_valid_response.json
similarity index 100%
rename from spec/fixtures/files/event_valid_response.json
rename to spec/fixtures/files/v3/event_valid_response.json
diff --git a/spec/fixtures/files/find_contact_valid_response.json b/spec/fixtures/files/v3/find_contact_valid_response.json
similarity index 100%
rename from spec/fixtures/files/find_contact_valid_response.json
rename to spec/fixtures/files/v3/find_contact_valid_response.json
diff --git a/spec/fixtures/files/find_group_valid_response.json b/spec/fixtures/files/v3/find_group_valid_response.json
similarity index 100%
rename from spec/fixtures/files/find_group_valid_response.json
rename to spec/fixtures/files/v3/find_group_valid_response.json
diff --git a/spec/fixtures/files/find_user_valid_response.json b/spec/fixtures/files/v3/find_user_valid_response.json
similarity index 100%
rename from spec/fixtures/files/find_user_valid_response.json
rename to spec/fixtures/files/v3/find_user_valid_response.json
diff --git a/spec/fixtures/files/list_contact_groups_valid_response.json b/spec/fixtures/files/v3/list_contact_groups_valid_response.json
similarity index 100%
rename from spec/fixtures/files/list_contact_groups_valid_response.json
rename to spec/fixtures/files/v3/list_contact_groups_valid_response.json
diff --git a/spec/fixtures/files/list_contact_memberships_valid_response.json b/spec/fixtures/files/v3/list_contact_memberships_valid_response.json
similarity index 100%
rename from spec/fixtures/files/list_contact_memberships_valid_response.json
rename to spec/fixtures/files/v3/list_contact_memberships_valid_response.json
diff --git a/spec/fixtures/files/list_contacts_in_group_valid_response.json b/spec/fixtures/files/v3/list_contacts_in_group_valid_response.json
similarity index 100%
rename from spec/fixtures/files/list_contacts_in_group_valid_response.json
rename to spec/fixtures/files/v3/list_contacts_in_group_valid_response.json
diff --git a/spec/fixtures/files/list_groups_valid_response.json b/spec/fixtures/files/v3/list_groups_valid_response.json
similarity index 100%
rename from spec/fixtures/files/list_groups_valid_response.json
rename to spec/fixtures/files/v3/list_groups_valid_response.json
diff --git a/spec/fixtures/files/list_membership_types_valid_response.json b/spec/fixtures/files/v3/list_membership_types_valid_response.json
similarity index 100%
rename from spec/fixtures/files/list_membership_types_valid_response.json
rename to spec/fixtures/files/v3/list_membership_types_valid_response.json
diff --git a/spec/fixtures/files/participant_valid_response.json b/spec/fixtures/files/v3/participant_valid_response.json
similarity index 100%
rename from spec/fixtures/files/participant_valid_response.json
rename to spec/fixtures/files/v3/participant_valid_response.json
diff --git a/spec/fixtures/files/v4/empty_response.json b/spec/fixtures/files/v4/empty_response.json
new file mode 100644
index 0000000..4d82fec
--- /dev/null
+++ b/spec/fixtures/files/v4/empty_response.json
@@ -0,0 +1,9 @@
+{
+  "values" : [],
+  "entity" : "",
+  "action" : "",
+  "version" : 4,
+  "count" : 0,
+  "countFetched" : 0,
+  "countMatched" : 0
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/error_response.json b/spec/fixtures/files/v4/error_response.json
new file mode 100644
index 0000000..dd39d13
--- /dev/null
+++ b/spec/fixtures/files/v4/error_response.json
@@ -0,0 +1,3 @@
+{
+  "is_error": 1
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/event_valid_response.json b/spec/fixtures/files/v4/event_valid_response.json
new file mode 100644
index 0000000..ce91d6b
--- /dev/null
+++ b/spec/fixtures/files/v4/event_valid_response.json
@@ -0,0 +1,19 @@
+{
+    "values": [
+        {
+            "id": 2,
+            "title": "Quaerat accusamus ducimus odit quibusdam.: Una trobada de prova",
+            "summary": null,
+            "description": null,
+            "event_type_id:label": "Quibusdam",
+            "start_date": "2020-12-03 18:00:00",
+            "end_date": "2020-12-03 19:30:00"
+        }
+    ],
+    "entity": "Event",
+    "action": "get",
+    "debug": null,
+    "version": 4,
+    "count": 1,
+    "countFetched": 1
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/find_contact_valid_response.json b/spec/fixtures/files/v4/find_contact_valid_response.json
new file mode 100644
index 0000000..a52328d
--- /dev/null
+++ b/spec/fixtures/files/v4/find_contact_valid_response.json
@@ -0,0 +1,15 @@
+{
+  "values": [
+      {
+          "id": 30,
+          "membership.membership_type_id": 3,
+          "display_name": "Roberto Abela Serra"
+      }
+  ],
+  "entity": "Contact",
+  "action": "get",
+  "debug": null,
+  "version": 4,
+  "count": 2,
+  "countFetched": 2
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/find_group_valid_response.json b/spec/fixtures/files/v4/find_group_valid_response.json
new file mode 100644
index 0000000..a24f18c
--- /dev/null
+++ b/spec/fixtures/files/v4/find_group_valid_response.json
@@ -0,0 +1,19 @@
+{
+  "values": [
+    {
+      "id": 1,
+      "name": "Administrators",
+      "title": "Administradors",
+      "description": "Als contactes d'aquest grup se'ls-hi assigna el rol administrador.",
+      "group_type": [
+          "1"
+      ]
+  }
+  ],
+  "entity": "Group",
+  "action": "get",
+  "debug": null,
+  "version": 4,
+  "count": 1,
+  "countFetched": 1
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/find_user_valid_response.json b/spec/fixtures/files/v4/find_user_valid_response.json
new file mode 100644
index 0000000..7d55952
--- /dev/null
+++ b/spec/fixtures/files/v4/find_user_valid_response.json
@@ -0,0 +1,18 @@
+{
+  "values": [
+    {
+      "id": 42122,
+      "uf_match.uf_id": 5,
+      "uf_match.contact_id": 42122,
+      "display_name": "Test User",
+      "email_primary.email": "testuser001@email.com",
+      "membership.membership_type_id:label": null
+    }
+  ],
+  "entity": "Contact",
+  "action": "get",
+  "debug": null,
+  "version": 4,
+  "count": 1,
+  "countFetched": 1
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/list_contact_groups_valid_response.json b/spec/fixtures/files/v4/list_contact_groups_valid_response.json
new file mode 100644
index 0000000..c90c3c6
--- /dev/null
+++ b/spec/fixtures/files/v4/list_contact_groups_valid_response.json
@@ -0,0 +1,23 @@
+{
+  "values": [
+    {
+        "id": 83427,
+        "group_id": 32
+    },
+    {
+        "id": 4692,
+        "group_id": 83
+    },
+    {
+        "id": 28668,
+        "group_id": 220
+    }
+  ],
+  "entity": "GroupContact",
+  "action": "get",
+  "debug": null,
+  "version": 4,
+  "count": 6,
+  "countFetched": 6,
+  "countMatched": 6
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/list_contact_memberships_valid_response.json b/spec/fixtures/files/v4/list_contact_memberships_valid_response.json
new file mode 100644
index 0000000..7ba893c
--- /dev/null
+++ b/spec/fixtures/files/v4/list_contact_memberships_valid_response.json
@@ -0,0 +1,19 @@
+{
+  "values": [
+    {
+        "id": 420,
+        "membership_type_id": 3
+    },
+    {
+        "id": 42745,
+        "membership_type_id": 4
+    }
+  ],
+  "entity": "Membership",
+  "action": "get",
+  "debug": null,
+  "version": 4,
+  "count": 2,
+  "countFetched": 2,
+  "countMatched": 2
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/list_contacts_in_group_valid_response.json b/spec/fixtures/files/v4/list_contacts_in_group_valid_response.json
new file mode 100644
index 0000000..a25751b
--- /dev/null
+++ b/spec/fixtures/files/v4/list_contacts_in_group_valid_response.json
@@ -0,0 +1,23 @@
+{
+  "values": [
+    {
+        "id": 17,
+        "display_name": "User 1"
+    },
+    {
+        "id": 18,
+        "display_name": "User 2"
+    },
+    {
+        "id": 23,
+        "display_name": "User 3"
+    }
+  ],
+  "entity": "Contact",
+  "action": "get",
+  "debug": null,
+  "version": 4,
+  "count": 3,
+  "countFetched": 3,
+  "countMatched": 3
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/list_groups_valid_response.json b/spec/fixtures/files/v4/list_groups_valid_response.json
new file mode 100644
index 0000000..fbcef8d
--- /dev/null
+++ b/spec/fixtures/files/v4/list_groups_valid_response.json
@@ -0,0 +1,28 @@
+{
+  "values": [
+    {
+      "id": "1",
+      "name": "Administrators",
+      "title": "Administrators",
+      "description": "The users in this group are assigned admin privileges.",
+      "group_type": [
+        "1"
+      ]
+    },
+    {
+      "id": "2",
+      "name": "Another_Group",
+      "title": "Another Group",
+      "description": "...",
+      "group_type": [
+        "2"
+      ]
+    }
+  ],
+  "entity": "Group",
+  "action": "get",
+  "debug": null,
+  "count": 2,
+  "countFetched": 2,
+  "countMatched": 2
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/list_membership_types_valid_response.json b/spec/fixtures/files/v4/list_membership_types_valid_response.json
new file mode 100644
index 0000000..bfb2720
--- /dev/null
+++ b/spec/fixtures/files/v4/list_membership_types_valid_response.json
@@ -0,0 +1,27 @@
+{
+  "values": [
+      {
+          "id": 1,
+          "name": "Info Puntual"
+      },
+      {
+          "id": 2,
+          "name": "Interessat"
+      },
+      {
+          "id": 3,
+          "name": "Inscrit"
+      },
+      {
+          "id": 4,
+          "name": "Rebut domiciliat"
+      }
+  ],
+  "entity": "MembershipType",
+  "action": "get",
+  "debug": null,
+  "version": 4,
+  "count": 4,
+  "countFetched": 4,
+  "countMatched": 4
+}
\ No newline at end of file
diff --git a/spec/fixtures/files/v4/participant_valid_response.json b/spec/fixtures/files/v4/participant_valid_response.json
new file mode 100644
index 0000000..2bc64a6
--- /dev/null
+++ b/spec/fixtures/files/v4/participant_valid_response.json
@@ -0,0 +1,19 @@
+{
+    "values": [
+        {
+            "id": 12,
+            "contact_id": 15070,
+            "contact_id.display_name": "Test User",
+            "status_id:label": "Inscrit",
+            "fee_amount": null,
+            "fee_level": null,
+            "fee_currency": null
+        }
+    ],
+    "entity": "Participant",
+    "action": "get",
+    "debug": null,
+    "version": 4,
+    "count": 1,
+    "countFetched": 1
+}
\ No newline at end of file
diff --git a/spec/forms/admin/event_meeting_form_spec.rb b/spec/forms/admin/v3/event_meeting_form_spec.rb
similarity index 92%
rename from spec/forms/admin/event_meeting_form_spec.rb
rename to spec/forms/admin/v3/event_meeting_form_spec.rb
index a780e3a..044ab12 100644
--- a/spec/forms/admin/event_meeting_form_spec.rb
+++ b/spec/forms/admin/v3/event_meeting_form_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim::Civicrm
   module Admin
@@ -10,7 +10,7 @@ module Admin
 
       include_context "with stubs example api"
 
-      let(:data) { JSON.parse(file_fixture("event_valid_response.json").read) }
+      let(:data) { JSON.parse(file_fixture("v3/event_valid_response.json").read) }
 
       let(:attributes) do
         {
diff --git a/spec/forms/admin/v4/event_meeting_form_spec.rb b/spec/forms/admin/v4/event_meeting_form_spec.rb
new file mode 100644
index 0000000..a81fd8c
--- /dev/null
+++ b/spec/forms/admin/v4/event_meeting_form_spec.rb
@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim::Civicrm
+  module Admin
+    describe EventMeetingForm do
+      subject { described_class.from_params(attributes) }
+
+      include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+      let(:data) { JSON.parse(file_fixture("v4/event_valid_response.json").read) }
+
+      let(:attributes) do
+        {
+          "event_meeting" => {
+            "decidim_meeting_id" => decidim_meeting_id,
+            "civicrm_event_id" => event_id,
+            "redirect_url" => redirect_url,
+            "redirect_active" => active
+          }
+        }
+      end
+      let(:meeting) { create :meeting }
+      let(:decidim_meeting_id) { meeting.id }
+      let(:redirect_url) { ::Faker::Internet.url }
+      let(:active) { true }
+      let(:event_id) { 123 }
+
+      context "when everything is OK" do
+        it { is_expected.to be_valid }
+      end
+
+      context "when no meeting" do
+        let(:decidim_meeting_id) { nil }
+
+        it { is_expected.to be_invalid }
+      end
+
+      context "when no url" do
+        let(:redirect_url) { nil }
+
+        it { is_expected.to be_valid }
+
+        context "and no civicrm_event_id" do
+          let(:event_id) { nil }
+
+          it { is_expected.to be_invalid }
+        end
+      end
+
+      context "when no event_id" do
+        let(:event_id) { nil }
+
+        it { is_expected.to be_valid }
+
+        context "and no url" do
+          let(:redirect_url) { nil }
+
+          it { is_expected.to be_invalid }
+        end
+      end
+
+      context "when civicrm event does not exist" do
+        let(:data) do
+          {
+            "values" => [],
+            "entity" => "Event",
+            "action" => "get",
+            "version" => 4,
+            "count" => 0,
+            "countFetched" => 0,
+            "countMatched" => 0
+          }
+        end
+
+        it { is_expected.to be_invalid }
+      end
+    end
+  end
+end
diff --git a/spec/forms/verifications/civicrm_groups_spec.rb b/spec/forms/verifications/v3/civicrm_groups_spec.rb
similarity index 77%
rename from spec/forms/verifications/civicrm_groups_spec.rb
rename to spec/forms/verifications/v3/civicrm_groups_spec.rb
index 0a5b520..c62cf7f 100644
--- a/spec/forms/verifications/civicrm_groups_spec.rb
+++ b/spec/forms/verifications/v3/civicrm_groups_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim::Civicrm
   module Verifications
@@ -10,7 +10,7 @@ module Verifications
 
       include_context "with stubs example api"
 
-      let(:data) { JSON.parse(file_fixture("find_user_valid_response.json").read) }
+      let(:data) { JSON.parse(file_fixture("v3/find_user_valid_response.json").read) }
 
       let(:attributes) do
         {
diff --git a/spec/forms/verifications/civicrm_membership_types_spec.rb b/spec/forms/verifications/v3/civicrm_membership_types_spec.rb
similarity index 77%
rename from spec/forms/verifications/civicrm_membership_types_spec.rb
rename to spec/forms/verifications/v3/civicrm_membership_types_spec.rb
index ae3d32d..512aae0 100644
--- a/spec/forms/verifications/civicrm_membership_types_spec.rb
+++ b/spec/forms/verifications/v3/civicrm_membership_types_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim::Civicrm
   module Verifications
@@ -10,7 +10,7 @@ module Verifications
 
       include_context "with stubs example api"
 
-      let(:data) { JSON.parse(file_fixture("find_user_valid_response.json").read) }
+      let(:data) { JSON.parse(file_fixture("v3/find_user_valid_response.json").read) }
 
       let(:attributes) do
         {
diff --git a/spec/forms/verifications/civicrm_spec.rb b/spec/forms/verifications/v3/civicrm_spec.rb
similarity index 76%
rename from spec/forms/verifications/civicrm_spec.rb
rename to spec/forms/verifications/v3/civicrm_spec.rb
index eedca37..dc603c2 100644
--- a/spec/forms/verifications/civicrm_spec.rb
+++ b/spec/forms/verifications/v3/civicrm_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim::Civicrm
   module Verifications
@@ -10,7 +10,7 @@ module Verifications
 
       include_context "with stubs example api"
 
-      let(:data) { JSON.parse(file_fixture("find_user_valid_response.json").read) }
+      let(:data) { JSON.parse(file_fixture("v3/find_user_valid_response.json").read) }
 
       let(:attributes) do
         {
diff --git a/spec/forms/verifications/v4/civicrm_groups_spec.rb b/spec/forms/verifications/v4/civicrm_groups_spec.rb
new file mode 100644
index 0000000..f400d56
--- /dev/null
+++ b/spec/forms/verifications/v4/civicrm_groups_spec.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim::Civicrm
+  module Verifications
+    describe CivicrmGroups do
+      subject { described_class.from_params(attributes) }
+
+      include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+      let(:data) { JSON.parse(file_fixture("v4/find_user_valid_response.json").read) }
+
+      let(:attributes) do
+        {
+          "user" => user
+        }
+      end
+      let(:user) { create :user }
+
+      context "when everything is OK" do
+        it { is_expected.to be_valid }
+      end
+    end
+  end
+end
diff --git a/spec/forms/verifications/v4/civicrm_membership_types_spec.rb b/spec/forms/verifications/v4/civicrm_membership_types_spec.rb
new file mode 100644
index 0000000..b63632d
--- /dev/null
+++ b/spec/forms/verifications/v4/civicrm_membership_types_spec.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim::Civicrm
+  module Verifications
+    describe CivicrmMembershipTypes do
+      subject { described_class.from_params(attributes) }
+
+      include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+      let(:data) { JSON.parse(file_fixture("v4/find_user_valid_response.json").read) }
+
+      let(:attributes) do
+        {
+          "user" => user
+        }
+      end
+      let(:user) { create :user }
+
+      context "when everything is OK" do
+        it { is_expected.to be_valid }
+      end
+    end
+  end
+end
diff --git a/spec/forms/verifications/v4/civicrm_spec.rb b/spec/forms/verifications/v4/civicrm_spec.rb
new file mode 100644
index 0000000..419ade2
--- /dev/null
+++ b/spec/forms/verifications/v4/civicrm_spec.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim::Civicrm
+  module Verifications
+    describe Civicrm do
+      subject { described_class.from_params(attributes) }
+
+      include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+      let(:data) { JSON.parse(file_fixture("v4/find_user_valid_response.json").read) }
+
+      let(:attributes) do
+        {
+          "user" => user
+        }
+      end
+      let(:user) { create :user }
+
+      context "when everything is OK" do
+        it { is_expected.to be_valid }
+      end
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/base/request_spec.rb b/spec/lib/civicrm/api/v3/base/request_spec.rb
similarity index 93%
rename from spec/lib/civicrm/api/base/request_spec.rb
rename to spec/lib/civicrm/api/v3/base/request_spec.rb
index 2a802af..3b3c387 100644
--- a/spec/lib/civicrm/api/base/request_spec.rb
+++ b/spec/lib/civicrm/api/v3/base/request_spec.rb
@@ -1,10 +1,10 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
-  describe Civicrm::Api::Base::Request, type: :class do
+  describe Civicrm::Api::Base::V3::Request, type: :class do
     subject { described_class }
 
     include_context "with stubs example api"
diff --git a/spec/lib/civicrm/api/find_contact_spec.rb b/spec/lib/civicrm/api/v3/find_contact_spec.rb
similarity index 85%
rename from spec/lib/civicrm/api/find_contact_spec.rb
rename to spec/lib/civicrm/api/v3/find_contact_spec.rb
index b6ed30e..ba13ccb 100644
--- a/spec/lib/civicrm/api/find_contact_spec.rb
+++ b/spec/lib/civicrm/api/v3/find_contact_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
   describe Civicrm::Api::FindContact, type: :class do
@@ -9,7 +9,7 @@ module Decidim
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("find_contact_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/find_contact_valid_response.json").read) }
 
     describe "#result" do
       it "returns a mapped object" do
diff --git a/spec/lib/civicrm/api/find_group_spec.rb b/spec/lib/civicrm/api/v3/find_group_spec.rb
similarity index 84%
rename from spec/lib/civicrm/api/find_group_spec.rb
rename to spec/lib/civicrm/api/v3/find_group_spec.rb
index a8b0dac..76bf014 100644
--- a/spec/lib/civicrm/api/find_group_spec.rb
+++ b/spec/lib/civicrm/api/v3/find_group_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
   describe Civicrm::Api::FindGroup, type: :class do
@@ -9,7 +9,7 @@ module Decidim
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("find_group_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/find_group_valid_response.json").read) }
 
     describe "#result" do
       it "returns a mapped object" do
diff --git a/spec/lib/civicrm/api/find_user_spec.rb b/spec/lib/civicrm/api/v3/find_user_spec.rb
similarity index 90%
rename from spec/lib/civicrm/api/find_user_spec.rb
rename to spec/lib/civicrm/api/v3/find_user_spec.rb
index c275ab7..d4842bb 100644
--- a/spec/lib/civicrm/api/find_user_spec.rb
+++ b/spec/lib/civicrm/api/v3/find_user_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
   describe Civicrm::Api::FindUser, type: :class do
@@ -9,7 +9,7 @@ module Decidim
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("find_user_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/find_user_valid_response.json").read) }
 
     describe "#result" do
       it "returns a mapped object" do
diff --git a/spec/lib/civicrm/api/list_contact_groups_spec.rb b/spec/lib/civicrm/api/v3/list_contact_groups_spec.rb
similarity index 68%
rename from spec/lib/civicrm/api/list_contact_groups_spec.rb
rename to spec/lib/civicrm/api/v3/list_contact_groups_spec.rb
index f7c319a..51189e3 100644
--- a/spec/lib/civicrm/api/list_contact_groups_spec.rb
+++ b/spec/lib/civicrm/api/v3/list_contact_groups_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
   describe Civicrm::Api::ListContactGroups, type: :class do
@@ -9,7 +9,7 @@ module Decidim
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("list_contact_groups_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/list_contact_groups_valid_response.json").read) }
 
     describe "#result" do
       it_behaves_like "returns mapped array ids", "group_id"
diff --git a/spec/lib/civicrm/api/list_contact_memberships_spec.rb b/spec/lib/civicrm/api/v3/list_contact_memberships_spec.rb
similarity index 69%
rename from spec/lib/civicrm/api/list_contact_memberships_spec.rb
rename to spec/lib/civicrm/api/v3/list_contact_memberships_spec.rb
index e741bb7..102419a 100644
--- a/spec/lib/civicrm/api/list_contact_memberships_spec.rb
+++ b/spec/lib/civicrm/api/v3/list_contact_memberships_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
   describe Civicrm::Api::ListContactMemberships, type: :class do
@@ -9,7 +9,7 @@ module Decidim
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("list_contact_memberships_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/list_contact_memberships_valid_response.json").read) }
 
     describe "#result" do
       it_behaves_like "returns mapped array ids", "membership_type_id"
diff --git a/spec/lib/civicrm/api/list_contacts_in_group_spec.rb b/spec/lib/civicrm/api/v3/list_contacts_in_group_spec.rb
similarity index 80%
rename from spec/lib/civicrm/api/list_contacts_in_group_spec.rb
rename to spec/lib/civicrm/api/v3/list_contacts_in_group_spec.rb
index c17390b..4f09aad 100644
--- a/spec/lib/civicrm/api/list_contacts_in_group_spec.rb
+++ b/spec/lib/civicrm/api/v3/list_contacts_in_group_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
   describe Civicrm::Api::ListContactsInGroup, type: :class do
@@ -9,7 +9,7 @@ module Decidim
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("list_contacts_in_group_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/list_contacts_in_group_valid_response.json").read) }
 
     describe "#result" do
       it "returns array of objects" do
diff --git a/spec/lib/civicrm/api/list_groups_spec.rb b/spec/lib/civicrm/api/v3/list_groups_spec.rb
similarity index 83%
rename from spec/lib/civicrm/api/list_groups_spec.rb
rename to spec/lib/civicrm/api/v3/list_groups_spec.rb
index 4eb27e0..fd3e943 100644
--- a/spec/lib/civicrm/api/list_groups_spec.rb
+++ b/spec/lib/civicrm/api/v3/list_groups_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
   describe Civicrm::Api::ListGroups, type: :class do
@@ -9,7 +9,7 @@ module Decidim
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("list_groups_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/list_groups_valid_response.json").read) }
 
     describe "#result" do
       it "returns array of objects" do
diff --git a/spec/lib/civicrm/api/list_membership_types_spec.rb b/spec/lib/civicrm/api/v3/list_membership_types_spec.rb
similarity index 79%
rename from spec/lib/civicrm/api/list_membership_types_spec.rb
rename to spec/lib/civicrm/api/v3/list_membership_types_spec.rb
index 340c8c6..cdee941 100644
--- a/spec/lib/civicrm/api/list_membership_types_spec.rb
+++ b/spec/lib/civicrm/api/v3/list_membership_types_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim
   describe Civicrm::Api::ListMembershipTypes, type: :class do
@@ -9,7 +9,7 @@ module Decidim
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("list_membership_types_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/list_membership_types_valid_response.json").read) }
 
     describe "#result" do
       it "returns array of objects" do
diff --git a/spec/lib/civicrm/api/v4/base/request_spec.rb b/spec/lib/civicrm/api/v4/base/request_spec.rb
new file mode 100644
index 0000000..9265dc6
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/base/request_spec.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::Base::V4::Request, type: :class do
+    subject { described_class }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    describe "#get petition" do
+      it "returns a connection instance" do
+        expect(subject.get(entity, params, action).connection).to be_a(Faraday::Connection)
+      end
+
+      it "returns a response parsed into a ruby Hash" do
+        expect(subject.get(entity, params, action).response).to be_a(Hash)
+        expect(subject.get(entity, params, action).response).to eq(data)
+      end
+
+      context "when is not succesful" do
+        let(:http_status) { 500 }
+        let(:data) do
+          {
+            "is_error" => 1,
+            "version" => 3
+          }
+        end
+
+        it "throws error" do
+          expect { subject.get(entity, params, action) }.to raise_error Decidim::Civicrm::Error
+        end
+      end
+    end
+
+    describe "#post petition" do
+      let(:http_method) { :post }
+
+      it "returns a connection instance" do
+        expect(subject.post(entity, params, action).connection).to be_a(Faraday::Connection)
+      end
+
+      it "returns a response parsed into a ruby Hash" do
+        expect(subject.post(entity, params, action).response).to be_a(Hash)
+        expect(subject.post(entity, params, action).response).to eq(data)
+      end
+
+      context "when is not succesful" do
+        let(:http_status) { 500 }
+        let(:data) do
+          {
+            "is_error" => 1,
+            "version" => 3
+          }
+        end
+
+        it "throws error" do
+          expect { subject.post(entity, params, action) }.to raise_error Decidim::Civicrm::Error
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/v4/find_contact_spec.rb b/spec/lib/civicrm/api/v4/find_contact_spec.rb
new file mode 100644
index 0000000..dbe5af7
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/find_contact_spec.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::FindContact, type: :class do
+    subject { described_class.new(42) }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/find_contact_valid_response.json").read) }
+
+    describe "#result" do
+      it "returns a mapped object" do
+        expect(subject.result).to be_a Hash
+        expect(subject.result[:contact]).to be_a Hash
+        expect(subject.result[:memberships]).to be_a Array
+        expect(subject.result[:contact]).to be_a Hash
+        expect(subject.result[:contact][:id]).to eq(data["values"].first["id"].to_i)
+        expect(subject.result[:contact][:display_name]).to eq(data["values"].first["display_name"])
+        expect(subject.result[:memberships].first).to eq(data["values"].first["membership.membership_type_id"])
+      end
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/v4/find_group_spec.rb b/spec/lib/civicrm/api/v4/find_group_spec.rb
new file mode 100644
index 0000000..c2ea766
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/find_group_spec.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::FindGroup, type: :class do
+    subject { described_class.new(1) }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/find_group_valid_response.json").read) }
+
+    describe "#result" do
+      it "returns a mapped object" do
+        expect(subject.result).to be_a Hash
+        expect(subject.result[:group_type]).to eq(data["values"].first["group_type"].map(&:to_i))
+        expect(subject.result[:title]).to eq(data["values"].first["title"])
+        expect(subject.result[:id]).to eq(data["values"].first["id"].to_i)
+        expect(subject.result[:name]).to eq(data["values"].first["name"])
+        expect(subject.result[:description]).to eq(data["values"].first["description"])
+      end
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/v4/find_user_spec.rb b/spec/lib/civicrm/api/v4/find_user_spec.rb
new file mode 100644
index 0000000..7157c3b
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/find_user_spec.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::FindUser, type: :class do
+    subject { described_class.new(42) }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/find_user_valid_response.json").read) }
+
+    describe "#result" do
+      it "returns a mapped object" do
+        expect(subject.result).to be_a Hash
+        expect(subject.result[:user]).to be_a Hash
+        expect(subject.result[:memberships]).to be_a Array
+        expect(subject.result[:contact]).to be_a Hash
+        expect(subject.result[:user][:id]).to eq(data["values"].first["id"].to_i)
+        expect(subject.result[:user][:name]).to eq(data["values"].first["name"])
+        expect(subject.result[:user][:email]).to eq(data["values"].first["email_primary.email"])
+        expect(subject.result[:user][:contact_id]).to eq(data["values"].first["id"].to_i)
+        expect(subject.result[:contact][:id]).to eq(data["values"].first["id"].to_i)
+        expect(subject.result[:contact][:display_name]).to eq(data["values"].first["display_name"])
+      end
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/v4/list_contact_groups_spec.rb b/spec/lib/civicrm/api/v4/list_contact_groups_spec.rb
new file mode 100644
index 0000000..611b391
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/list_contact_groups_spec.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::ListContactGroups, type: :class do
+    subject { described_class.new(1) }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/list_contact_groups_valid_response.json").read) }
+
+    describe "#result" do
+      it_behaves_like "returns mapped array ids #{Decidim::Civicrm::Api.available_versions[:v4]}", "group_id"
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/v4/list_contact_memberships_spec.rb b/spec/lib/civicrm/api/v4/list_contact_memberships_spec.rb
new file mode 100644
index 0000000..1e4bf24
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/list_contact_memberships_spec.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::ListContactMemberships, type: :class do
+    subject { described_class.new(1) }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/list_contact_memberships_valid_response.json").read) }
+
+    describe "#result" do
+      it_behaves_like "returns mapped array ids #{Decidim::Civicrm::Api.available_versions[:v4]}", "membership_type_id"
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/v4/list_contacts_in_group_spec.rb b/spec/lib/civicrm/api/v4/list_contacts_in_group_spec.rb
new file mode 100644
index 0000000..38a4f0c
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/list_contacts_in_group_spec.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::ListContactsInGroup, type: :class do
+    subject { described_class.new(1) }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/list_contacts_in_group_valid_response.json").read) }
+
+    describe "#result" do
+      it "returns array of objects" do
+        expect(subject.result).to be_a Array
+        data["values"].each do |member|
+          member = {
+            contact_id: member["id"].to_i,
+            display_name: member["display_name"]
+          }
+          expect(subject.result).to include(member)
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/v4/list_groups_spec.rb b/spec/lib/civicrm/api/v4/list_groups_spec.rb
new file mode 100644
index 0000000..fbfe18f
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/list_groups_spec.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::ListGroups, type: :class do
+    subject { described_class.new }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/list_groups_valid_response.json").read) }
+
+    describe "#result" do
+      it "returns array of objects" do
+        expect(subject.result).to be_a Array
+        data["values"].each do |group|
+          group = {
+            id: group["id"].to_i,
+            name: group["name"],
+            title: group["title"],
+            description: group["description"],
+            group_type: group["group_type"].map(&:to_i)
+          }
+          expect(subject.result).to include(group)
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/civicrm/api/v4/list_membership_types_spec.rb b/spec/lib/civicrm/api/v4/list_membership_types_spec.rb
new file mode 100644
index 0000000..9b72f62
--- /dev/null
+++ b/spec/lib/civicrm/api/v4/list_membership_types_spec.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim
+  describe Civicrm::Api::ListMembershipTypes, type: :class do
+    subject { described_class.new }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/list_membership_types_valid_response.json").read) }
+
+    describe "#result" do
+      it "returns array of objects" do
+        expect(subject.result).to be_a Array
+        data["values"].each do |group|
+          group = {
+            id: group["id"].to_i,
+            name: group["name"]
+          }
+          expect(subject.result).to include(group)
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/civicrm/civicrm_automatic_verification_spec.rb b/spec/lib/civicrm/v3/civicrm_automatic_verification_spec.rb
similarity index 100%
rename from spec/lib/civicrm/civicrm_automatic_verification_spec.rb
rename to spec/lib/civicrm/v3/civicrm_automatic_verification_spec.rb
diff --git a/spec/lib/civicrm/v4/civicrm_automatic_verification_spec.rb b/spec/lib/civicrm/v4/civicrm_automatic_verification_spec.rb
new file mode 100644
index 0000000..db476d1
--- /dev/null
+++ b/spec/lib/civicrm/v4/civicrm_automatic_verification_spec.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+# rubocop:disable RSpec/DescribeClass
+describe "Automatic verification after oauth sign up" do
+  context "when a user is registered with omniauth" do
+    let!(:user) { create(:user) }
+
+    it "runs the OmniauthContactSyncJob" do
+      expect do
+        ActiveSupport::Notifications.publish(
+          "decidim.user.omniauth_registration",
+          user_id: user.id,
+          identity_id: 1234,
+          provider: "civicrm",
+          uid: "aaa",
+          email: user.email,
+          name: "Civicrm User",
+          nickname: "civicrm_user",
+          avatar_url: "http://www.example.com/foo.jpg",
+          raw_data: {}
+        )
+      end.to have_enqueued_job(Decidim::Civicrm::OmniauthContactSyncJob)
+    end
+  end
+
+  context "when a contact is updated" do
+    let!(:contact) { create(:civicrm_contact) }
+
+    it "runs the AutoVerificationJob" do
+      expect do
+        ActiveSupport::Notifications.publish(
+          "decidim.civicrm.contact.updated",
+          contact_id: contact.id
+        )
+      end.to have_enqueued_job(Decidim::Civicrm::AutoVerificationJob)
+    end
+
+    it "runs the JoinContactToParticipatorySpacesJob" do
+      expect do
+        ActiveSupport::Notifications.publish(
+          "decidim.civicrm.contact.updated",
+          contact_id: contact.id
+        )
+      end.to have_enqueued_job(Decidim::Civicrm::JoinContactToParticipatorySpacesJob)
+    end
+  end
+end
+
+# rubocop:enable RSpec/DescribeClass
diff --git a/spec/lib/event_parsers/event_meeting_parser_spec.rb b/spec/lib/event_parsers/v3/event_meeting_parser_spec.rb
similarity index 92%
rename from spec/lib/event_parsers/event_meeting_parser_spec.rb
rename to spec/lib/event_parsers/v3/event_meeting_parser_spec.rb
index 0b9429f..2fc54b8 100644
--- a/spec/lib/event_parsers/event_meeting_parser_spec.rb
+++ b/spec/lib/event_parsers/v3/event_meeting_parser_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim::Civicrm
   describe EventParsers::EventMeetingParser, type: :class do
@@ -9,7 +9,7 @@ module Decidim::Civicrm
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("event_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/event_valid_response.json").read) }
 
     let(:meeting) { create :meeting }
     let(:json) do
diff --git a/spec/lib/event_parsers/event_registration_parser_spec.rb b/spec/lib/event_parsers/v3/event_registration_parser_spec.rb
similarity index 93%
rename from spec/lib/event_parsers/event_registration_parser_spec.rb
rename to spec/lib/event_parsers/v3/event_registration_parser_spec.rb
index 722d8fa..37bc283 100644
--- a/spec/lib/event_parsers/event_registration_parser_spec.rb
+++ b/spec/lib/event_parsers/v3/event_registration_parser_spec.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "spec_helper"
-require "decidim/civicrm/test/shared_contexts"
+require "decidim/civicrm/test/v3/shared_contexts"
 
 module Decidim::Civicrm
   describe EventParsers::EventRegistrationParser, type: :class do
@@ -9,7 +9,7 @@ module Decidim::Civicrm
 
     include_context "with stubs example api"
 
-    let(:data) { JSON.parse(file_fixture("participant_valid_response.json").read) }
+    let(:data) { JSON.parse(file_fixture("v3/participant_valid_response.json").read) }
 
     let(:registration) { create :registration }
     let(:organization) { meeting.organization }
diff --git a/spec/lib/event_parsers/v4/event_meeting_parser_spec.rb b/spec/lib/event_parsers/v4/event_meeting_parser_spec.rb
new file mode 100644
index 0000000..7462b79
--- /dev/null
+++ b/spec/lib/event_parsers/v4/event_meeting_parser_spec.rb
@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim::Civicrm
+  describe EventParsers::EventMeetingParser, type: :class do
+    subject { described_class.new(meeting) }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/event_valid_response.json").read) }
+
+    let(:meeting) { create :meeting }
+    let(:json) do
+      {
+        start_date: meeting.start_time.strftime("%Y%m%d"),
+        end_date: meeting.end_time.strftime("%Y%m%d"),
+        title: "#{meeting.participatory_space.title["ca"]}: #{meeting.title["ca"]}",
+        template_id: template_id
+      }
+    end
+    let(:template_id) { 666 }
+    let(:attributes) do
+      { template_id: template_id }
+    end
+    let(:parser_data) do
+      {
+        entity: "Event",
+        action: "create",
+        json: 1
+      }
+    end
+    let(:result) do
+      {
+        "id" => "123"
+      }
+    end
+
+    before do
+      subject.result = result
+      allow(Decidim::Civicrm).to receive(:auto_sync_meetings_event_attributes).and_return(attributes)
+    end
+
+    it "is valid" do
+      expect(subject.valid?).to be(true)
+    end
+
+    it "returns data" do
+      expect(subject.json).to eq(json)
+      expect(subject.data).to eq(parser_data.merge(json))
+    end
+
+    it "saves data" do
+      expect { subject.save! }.to change(Decidim::Civicrm::EventMeeting, :count).by(1)
+    end
+
+    context "when no result" do
+      let(:result) do
+        {
+          "id" => ""
+        }
+      end
+
+      it "don't save data" do
+        expect { subject.save! }.to raise_error ActiveRecord::RecordInvalid
+        expect(Decidim::Civicrm::EventMeeting.count).to eq(0)
+      end
+    end
+  end
+end
diff --git a/spec/lib/event_parsers/v4/event_registration_parser_spec.rb b/spec/lib/event_parsers/v4/event_registration_parser_spec.rb
new file mode 100644
index 0000000..4b8de11
--- /dev/null
+++ b/spec/lib/event_parsers/v4/event_registration_parser_spec.rb
@@ -0,0 +1,78 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+require "decidim/civicrm/test/v4/shared_contexts"
+
+module Decidim::Civicrm
+  describe EventParsers::EventRegistrationParser, type: :class do
+    subject { described_class.new(registration) }
+
+    include_context "with stubs example api #{Decidim::Civicrm::Api.available_versions[:v4]}"
+
+    let(:data) { JSON.parse(file_fixture("v4/participant_valid_response.json").read) }
+
+    let(:registration) { create :registration }
+    let(:organization) { meeting.organization }
+    let(:meeting) { registration.meeting }
+    let!(:authorization) { create :authorization, name: "civicrm", user: registration.user, metadata: { contact_id: contact_id } }
+    let!(:event_meeting) { create :civicrm_event_meeting, organization: organization, meeting: meeting, civicrm_event_id: event_id }
+    let(:contact_id) { 451 }
+    let(:event_id) { 2345 }
+    let(:json) do
+      {
+        event_id: event_id,
+        contact_id: contact_id
+      }
+    end
+    let(:parser_data) do
+      {
+        entity: "Participant",
+        action: "create",
+        json: 1
+      }
+    end
+    let(:result) do
+      {
+        "id" => "123"
+      }
+    end
+
+    before do
+      subject.result = result
+    end
+
+    it "is valid" do
+      expect(subject.valid?).to be(true)
+    end
+
+    it "returns data" do
+      expect(subject.json).to eq(json)
+      expect(subject.data).to eq(parser_data.merge(json))
+    end
+
+    it "saves data" do
+      expect { subject.save! }.to change(Decidim::Civicrm::EventRegistration, :count).by(1)
+    end
+
+    context "when no result" do
+      let(:result) do
+        {
+          "id" => ""
+        }
+      end
+
+      it "don't save data" do
+        expect { subject.save! }.to raise_error ActiveRecord::RecordInvalid
+        expect(Decidim::Civicrm::EventRegistration.count).to eq(0)
+      end
+    end
+
+    context "when no contact_id" do
+      let(:contact_id) { nil }
+
+      it "is invalid" do
+        expect(subject.valid?).to be(false)
+      end
+    end
+  end
+end
diff --git a/spec/omni_auth/strategies/civicrm_spec.rb b/spec/omni_auth/strategies/civicrm_spec.rb
new file mode 100644
index 0000000..bb52c15
--- /dev/null
+++ b/spec/omni_auth/strategies/civicrm_spec.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe OmniAuth::Strategies::Civicrm do
+  subject { described_class.new(nil, {}) }
+
+  let(:extra) { { contact: { display_name: "John+Doe" } } }
+  let(:raw_info) { { "preferred_username" => "john.doe" } }
+
+  before do
+    allow_any_instance_of(described_class).to receive(:extra).and_return(extra)
+    allow_any_instance_of(described_class).to receive(:raw_info).and_return(raw_info)
+  end
+
+  context "when the name is invalid" do
+    it "is sanitized" do
+      expect(subject.parsed_name).to eq("JohnDoe")
+    end
+  end
+
+  context "when the nickname is invalid" do
+    it "is sanitized" do
+      expect(subject.parsed_nickname).to eq("john_doe")
+    end
+  end
+end