diff --git a/db/migrations/20210216_add_pacticipant_columns.rb b/db/migrations/20210216_add_pacticipant_columns.rb
new file mode 100644
index 000000000..b91d21ef7
--- /dev/null
+++ b/db/migrations/20210216_add_pacticipant_columns.rb
@@ -0,0 +1,10 @@
+Sequel.migration do
+  change do
+    alter_table(:pacticipants) do
+      add_column(:display_name, String)
+      add_column(:repository_name, String)
+      add_column(:repository_namespace, String)
+      add_column(:main_development_branches, String)
+    end
+  end
+end
diff --git a/lib/pact_broker/api.rb b/lib/pact_broker/api.rb
index 9fb2505ed..b4240544e 100644
--- a/lib/pact_broker/api.rb
+++ b/lib/pact_broker/api.rb
@@ -11,6 +11,15 @@ class Request
     def patch?
       method == "PATCH"
     end
+
+    # This makes PATCH go through the PUT state machine path
+    def put?
+      method == "PUT" || method == "PATCH"
+    end
+
+    def really_put?
+      method == "PUT"
+    end
   end
 end
 
diff --git a/lib/pact_broker/api/contracts/dry_validation_workarounds.rb b/lib/pact_broker/api/contracts/dry_validation_workarounds.rb
index c2487828a..3c1a8390b 100644
--- a/lib/pact_broker/api/contracts/dry_validation_workarounds.rb
+++ b/lib/pact_broker/api/contracts/dry_validation_workarounds.rb
@@ -14,8 +14,13 @@ def select_first_message(messages)
         end
 
         def flatten_array_of_hashes(array_of_hashes)
-          new_messages = array_of_hashes.collect do | index, hash |
-            hash.values.flatten.collect { | text | "#{text} at index #{index}"}
+          new_messages = array_of_hashes.collect do | index, hash_or_array |
+            array = if hash_or_array.is_a?(Hash)
+              hash_or_array.values.flatten
+            else
+              hash_or_array
+            end
+            array.collect { | text | "#{text} at index #{index}"}
           end.flatten
         end
 
diff --git a/lib/pact_broker/api/contracts/pacticipant_schema.rb b/lib/pact_broker/api/contracts/pacticipant_schema.rb
new file mode 100644
index 000000000..677e6c509
--- /dev/null
+++ b/lib/pact_broker/api/contracts/pacticipant_schema.rb
@@ -0,0 +1,34 @@
+require 'dry-validation'
+require 'pact_broker/api/contracts/dry_validation_workarounds'
+require 'pact_broker/api/contracts/dry_validation_predicates'
+require 'pact_broker/messages'
+
+module PactBroker
+  module Api
+    module Contracts
+      class PacticipantSchema
+        extend DryValidationWorkarounds
+        extend PactBroker::Messages
+        using PactBroker::HashRefinements
+
+        SCHEMA = Dry::Validation.Schema do
+          configure do
+            predicates(DryValidationPredicates)
+            config.messages_file = File.expand_path("../../../locale/en.yml", __FILE__)
+          end
+          optional(:name).filled(:str?, :single_line?)
+          optional(:displayName).maybe(:str?, :single_line?, :not_blank?)
+          optional(:mainDevelopmentBranches).each(:str?, :single_line?, :no_spaces?)
+          optional(:repositoryUrl).maybe(:str?, :single_line?)
+          optional(:repositoryName).maybe(:str?, :single_line?)
+          optional(:repositoryNamespace).maybe(:str?, :single_line?)
+        end
+
+        def self.call(params_with_string_keys)
+          params = params_with_string_keys&.symbolize_keys
+          select_first_message(flatten_indexed_messages(SCHEMA.call(params).messages(full: true)))
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact_broker/api/decorators/pacticipant_decorator.rb b/lib/pact_broker/api/decorators/pacticipant_decorator.rb
index 4345941f6..0ef0aff69 100644
--- a/lib/pact_broker/api/decorators/pacticipant_decorator.rb
+++ b/lib/pact_broker/api/decorators/pacticipant_decorator.rb
@@ -8,9 +8,12 @@ module PactBroker
   module Api
     module Decorators
       class PacticipantDecorator < BaseDecorator
-
         property :name
-        property :repository_url, as: :repositoryUrl
+        property :display_name, camelize: true
+        property :repository_url, camelize: true
+        property :repository_name, camelize: true
+        property :repository_namespace, camelize: true
+        property :main_development_branches, camelize: true
 
         property :latest_version, as: :latestVersion, :class => PactBroker::Domain::Version, extend: PactBroker::Api::Decorators::EmbeddedVersionDecorator, embedded: true, writeable: false
         collection :labels, :class => PactBroker::Domain::Label, extend: PactBroker::Api::Decorators::EmbeddedLabelDecorator, embedded: true
diff --git a/lib/pact_broker/api/resources/default_base_resource.rb b/lib/pact_broker/api/resources/default_base_resource.rb
index e901a637b..2bfe11bcb 100644
--- a/lib/pact_broker/api/resources/default_base_resource.rb
+++ b/lib/pact_broker/api/resources/default_base_resource.rb
@@ -249,8 +249,12 @@ def decorator_class(name)
           application_context.decorator_configuration.class_for(name)
         end
 
-        def validation_errors_for_schema?(schema, params_to_validate = params)
-          if (errors = schema.call(params_to_validate)).any?
+        def schema
+          nil
+        end
+
+        def validation_errors_for_schema?(schema_to_use = schema, params_to_validate = params)
+          if (errors = schema_to_use.call(params_to_validate)).any?
             set_json_validation_error_messages(errors)
             true
           else
diff --git a/lib/pact_broker/api/resources/pacticipant.rb b/lib/pact_broker/api/resources/pacticipant.rb
index a6b2eae3c..35db96806 100644
--- a/lib/pact_broker/api/resources/pacticipant.rb
+++ b/lib/pact_broker/api/resources/pacticipant.rb
@@ -1,12 +1,5 @@
 require 'pact_broker/api/resources/base_resource'
-
-module Webmachine
-  class Request
-    def put?
-      method == "PUT" || method == "PATCH"
-    end
-  end
-end
+require 'pact_broker/api/contracts/pacticipant_schema'
 
 module PactBroker
   module Api
@@ -22,19 +15,31 @@ def content_types_accepted
         end
 
         def allowed_methods
-          ["GET", "PATCH", "DELETE", "OPTIONS"]
+          ["GET", "PUT", "PATCH", "DELETE", "OPTIONS"]
         end
 
         def known_methods
           super + ['PATCH']
         end
 
+        def malformed_request?
+          if request.patch? || request.put?
+            invalid_json? || validation_errors_for_schema?
+          else
+            false
+          end
+        end
+
         def from_json
           if pacticipant
-            @pacticipant = pacticipant_service.update params(symbolize_names: false).merge('name' => pacticipant_name)
+            @pacticipant = update_existing_pacticipant
           else
-            @pacticipant = pacticipant_service.create params.merge(:name => pacticipant_name)
-            response.headers["Location"] = pacticipant_url(base_url, pacticipant)
+            if request.patch? # for backwards compatibility, wish I hadn't done this
+              @pacticipant = create_new_pacticipant
+              response.headers["Location"] = pacticipant_url(base_url, pacticipant)
+            else
+              return 404
+            end
           end
           response.body = to_json
         end
@@ -52,9 +57,29 @@ def to_json
           decorator_class(:pacticipant_decorator).new(pacticipant).to_json(decorator_options)
         end
 
+        def parsed_pacticipant(pacticipant)
+          decorator_class(:pacticipant_decorator).new(pacticipant).from_json(request_body)
+        end
+
         def policy_name
           :'pacticipants::pacticipant'
         end
+
+        def schema
+          PactBroker::Api::Contracts::PacticipantSchema
+        end
+
+        def update_existing_pacticipant
+          if request.really_put?
+            @pacticipant = pacticipant_service.replace(pacticipant_name, parsed_pacticipant(OpenStruct.new))
+          else
+            @pacticipant = pacticipant_service.update(pacticipant_name, parsed_pacticipant(pacticipant))
+          end
+        end
+
+        def create_new_pacticipant
+          pacticipant_service.create parsed_pacticipant(OpenStruct.new).to_h.merge(:name => pacticipant_name)
+        end
       end
     end
   end
diff --git a/lib/pact_broker/api/resources/pacticipants.rb b/lib/pact_broker/api/resources/pacticipants.rb
index f34e188b8..3517ea136 100644
--- a/lib/pact_broker/api/resources/pacticipants.rb
+++ b/lib/pact_broker/api/resources/pacticipants.rb
@@ -2,6 +2,7 @@
 require 'pact_broker/api/decorators/pacticipant_decorator'
 require 'pact_broker/domain/pacticipant'
 require 'pact_broker/hash_refinements'
+require 'pact_broker/api/contracts/pacticipant_schema'
 
 module PactBroker
   module Api
@@ -23,7 +24,7 @@ def allowed_methods
 
         def malformed_request?
           if request.post?
-            return invalid_json? || validation_errors?(new_model)
+            return invalid_json? || validation_errors_for_schema?
           end
           false
         end
@@ -33,7 +34,7 @@ def post_is_create?
         end
 
         def from_json
-          created_model = pacticipant_service.create(params.symbolize_keys.snakecase_keys.slice(:name, :repository_url))
+          created_model = pacticipant_service.create(parsed_pacticipant.to_h)
           response.body = decorator_for(created_model).to_json(decorator_options)
         end
 
@@ -53,8 +54,8 @@ def decorator_for model
           decorator_class(:pacticipant_decorator).new(model)
         end
 
-        def new_model
-          @new_model ||= decorator_for(PactBroker::Domain::Pacticipant.new).from_json(request.body.to_s)
+        def parsed_pacticipant
+          @new_model ||= decorator_for(OpenStruct.new).from_json(request_body)
         end
 
         def policy_name
@@ -63,6 +64,10 @@ def policy_name
 
         private
 
+        def schema
+          PactBroker::Api::Contracts::PacticipantSchema
+        end
+
         def pacticipants
           @pacticipants ||= pacticipant_service.find_all_pacticipants
         end
diff --git a/lib/pact_broker/db/data_migrations/set_pacticipant_display_name.rb b/lib/pact_broker/db/data_migrations/set_pacticipant_display_name.rb
new file mode 100644
index 000000000..c7a32903d
--- /dev/null
+++ b/lib/pact_broker/db/data_migrations/set_pacticipant_display_name.rb
@@ -0,0 +1,23 @@
+require 'pact_broker/db/data_migrations/helpers'
+require 'pact_broker/pacticipants/generate_display_name'
+
+module PactBroker
+  module DB
+    module DataMigrations
+      class SetPacticipantDisplayName
+        extend Helpers
+        extend PactBroker::Pacticipants::GenerateDisplayName
+
+        def self.call(connection)
+          if columns_exist?(connection, :pacticipants, [:name, :display_name])
+            connection[:pacticipants].where(display_name: nil).each do | row |
+              connection[:pacticipants]
+                .where(id: row[:id])
+                .update(display_name: generate_display_name(row[:name]))
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact_broker/db/migrate_data.rb b/lib/pact_broker/db/migrate_data.rb
index 906eeb3d4..224835dcc 100644
--- a/lib/pact_broker/db/migrate_data.rb
+++ b/lib/pact_broker/db/migrate_data.rb
@@ -22,6 +22,7 @@ def self.call database_connection, options = {}
         DataMigrations::SetCreatedAtForLatestPactPublications.call(database_connection)
         DataMigrations::SetCreatedAtForLatestVerifications.call(database_connection)
         DataMigrations::SetExtraColumnsForTags.call(database_connection)
+        DataMigrations::SetPacticipantDisplayName.call(database_connection)
       end
     end
   end
diff --git a/lib/pact_broker/deployments/environment.rb b/lib/pact_broker/deployments/environment.rb
index 32dfe5c37..b6101ccb2 100644
--- a/lib/pact_broker/deployments/environment.rb
+++ b/lib/pact_broker/deployments/environment.rb
@@ -5,7 +5,7 @@
 module PactBroker
   module Deployments
     class Environment < Sequel::Model
-      OPEN_STRUCT_TO_JSON = lambda { |thing| Sequel.object_to_json(thing.collect(&:to_h)) }
+      OPEN_STRUCT_TO_JSON = lambda { | open_struct | Sequel.object_to_json(open_struct.collect(&:to_h)) }
       JSON_TO_OPEN_STRUCT = lambda { | json | Sequel.parse_json(json).collect{ | hash| OpenStruct.new(hash) } }
       plugin :upsert, identifying_columns: [:uuid]
       plugin :serialization
diff --git a/lib/pact_broker/domain/pacticipant.rb b/lib/pact_broker/domain/pacticipant.rb
index 410133c7f..e087aca74 100644
--- a/lib/pact_broker/domain/pacticipant.rb
+++ b/lib/pact_broker/domain/pacticipant.rb
@@ -3,14 +3,22 @@
 require 'pact_broker/repositories/helpers'
 require 'pact_broker/versions/latest_version'
 require 'pact_broker/domain/label'
+require 'pact_broker/string_refinements'
+require 'pact_broker/pacticipants/generate_display_name'
 
 module PactBroker
   module Domain
     class Pacticipant < Sequel::Model
-
       include Messages
-      plugin :insert_ignore, identifying_columns: [:name]
+      include PactBroker::Pacticipants::GenerateDisplayName
+      using PactBroker::StringRefinements
+
+      plugin :serialization
+      SPACE_DELIMITED_STRING_TO_ARRAY = lambda { |string| string.split(" ") }
+      ARRAY_TO_SPACE_DELIMITED_STRING = lambda { |array| array.join(" ") }
+      serialize_attributes [ARRAY_TO_SPACE_DELIMITED_STRING, SPACE_DELIMITED_STRING_TO_ARRAY], :main_development_branches
 
+      plugin :insert_ignore, identifying_columns: [:name]
       plugin :timestamps, update_on_create: true
 
       set_primary_key :id
@@ -42,6 +50,13 @@ def before_destroy
         super
       end
 
+      def before_save
+        super
+        if display_name.nil? || display_name.to_s.blank?
+          self.display_name = generate_display_name(name)
+        end
+      end
+
       def latest_version
         versions.last
       end
@@ -50,12 +65,6 @@ def to_s
         "Pacticipant: id=#{id}, name=#{name}"
       end
 
-      def validate
-        messages = []
-        messages << message('errors.validation.attribute_missing', attribute: 'name') unless name
-        messages
-      end
-
       def any_versions?
         PactBroker::Domain::Version.where(pacticipant: self).any?
       end
diff --git a/lib/pact_broker/pacticipants/generate_display_name.rb b/lib/pact_broker/pacticipants/generate_display_name.rb
new file mode 100644
index 000000000..ce87cafa2
--- /dev/null
+++ b/lib/pact_broker/pacticipants/generate_display_name.rb
@@ -0,0 +1,27 @@
+require 'pact_broker/string_refinements'
+
+module PactBroker
+  module Pacticipants
+    module GenerateDisplayName
+      using PactBroker::StringRefinements
+
+      def self.call(name)
+        return nil if name.nil?
+        name
+          .to_s
+          .gsub(/([A-Z])([A-Z])([a-z])/,'\1 \2\3')
+          .gsub(/([a-z\d])([A-Z])(\S)/,'\1 \2\3')
+          .gsub(/(\S)([\-_\s\.])(\S)/, '\1 \3')
+          .gsub(/\s+/, " ")
+          .strip
+          .split(" ")
+          .collect{ |word| word.camelcase(true) }
+          .join(" ")
+      end
+
+      def generate_display_name(name)
+        GenerateDisplayName.call(name)
+      end
+    end
+  end
+end
diff --git a/lib/pact_broker/pacticipants/repository.rb b/lib/pact_broker/pacticipants/repository.rb
index f38d3076f..4a112ed5e 100644
--- a/lib/pact_broker/pacticipants/repository.rb
+++ b/lib/pact_broker/pacticipants/repository.rb
@@ -47,21 +47,37 @@ def find_by_name_or_create name
         if pacticipant = find_by_name(name)
           pacticipant
         else
-          create name: name
+          create(name: name)
         end
       end
 
       # Need to be able to handle two calls that make the pacticipant at the same time.
       # TODO raise error if attributes apart from name are different, because this indicates that
       # the second request is not at the same time.
-      def create args
+      def create params
         PactBroker::Domain::Pacticipant.new(
-          name: args[:name],
-          repository_url: args[:repository_url],
-          created_at: Sequel.datetime_class.now,
-          updated_at: Sequel.datetime_class.now
+          name: params.fetch(:name),
+          display_name: params[:display_name],
+          repository_url: params[:repository_url],
+          repository_name: params[:repository_name],
+          repository_namespace: params[:repository_namespace],
+          main_development_branches: params[:main_development_branches] || []
         ).insert_ignore
-        PactBroker::Domain::Pacticipant.find(name: args[:name])
+      end
+
+      def update(pacticipant_name, pacticipant)
+        pacticipant.name = pacticipant_name
+        pacticipant.save
+      end
+
+      def replace(pacticipant_name, open_struct_pacticipant)
+        PactBroker::Domain::Pacticipant.new(
+          display_name: open_struct_pacticipant.display_name,
+          repository_url: open_struct_pacticipant.repository_url,
+          repository_name: open_struct_pacticipant.repository_name,
+          repository_namespace: open_struct_pacticipant.repository_namespace,
+          main_development_branches: open_struct_pacticipant.main_development_branches || []
+        ).save
       end
 
       def pacticipant_names
diff --git a/lib/pact_broker/pacticipants/service.rb b/lib/pact_broker/pacticipants/service.rb
index f070a5b9b..fb6d2c889 100644
--- a/lib/pact_broker/pacticipants/service.rb
+++ b/lib/pact_broker/pacticipants/service.rb
@@ -12,7 +12,7 @@ class Service
       extend PactBroker::Services
       include PactBroker::Logging
 
-      def self.messages_for_potential_duplicate_pacticipants pacticipant_names, base_url
+      def self.messages_for_potential_duplicate_pacticipants(pacticipant_names, base_url)
         messages = []
         pacticipant_names.each do | name |
           potential_duplicate_pacticipants = find_potential_duplicate_pacticipants(name)
@@ -36,27 +36,27 @@ def self.find_all_pacticipants
         pacticipant_repository.find_all
       end
 
-      def self.find_pacticipant_by_name name
+      def self.find_pacticipant_by_name(name)
         pacticipant_repository.find_by_name(name)
       end
 
-      def self.find_pacticipant_by_name! name
+      def self.find_pacticipant_by_name!(name)
         pacticipant_repository.find_by_name!(name)
       end
 
-      def self.find_by_id id
+      def self.find_by_id(id)
         pacticipant_repository.find_by_id(id)
       end
 
-      def self.find options
+      def self.find(options)
         pacticipant_repository.find options
       end
 
-      def self.find_all_pacticipant_versions_in_reverse_order name, pagination_options = nil
+      def self.find_all_pacticipant_versions_in_reverse_order(name, pagination_options = nil)
         pacticipant_repository.find_all_pacticipant_versions_in_reverse_order(name, pagination_options)
       end
 
-      def self.find_pacticipant_repository_url_by_pacticipant_name name
+      def self.find_pacticipant_repository_url_by_pacticipant_name(name)
         pacticipant = pacticipant_repository.find_by_name(name)
         if pacticipant && pacticipant.repository_url
           pacticipant.repository_url
@@ -65,19 +65,19 @@ def self.find_pacticipant_repository_url_by_pacticipant_name name
         end
       end
 
-      def self.update params
-        # TODO move this to the repository!
-        pacticipant = pacticipant_repository.find_by_name(params.fetch('name'))
-        PactBroker::Api::Decorators::PacticipantDecorator.new(pacticipant).from_hash(params)
-        pacticipant.save
-        pacticipant_repository.find_by_name(params.fetch('name'))
+      def self.update(pacticipant_name, pacticipant)
+        pacticipant_repository.update(pacticipant_name, pacticipant)
       end
 
-      def self.create params
+      def self.create(params)
         pacticipant_repository.create(params)
       end
 
-      def self.delete name
+      def self.replace(pacticipant_name, open_struct_pacticipant)
+        pacticipant_repository.replace(pacticipant_name, open_struct_pacticipant)
+      end
+
+      def self.delete(name)
         pacticipant = find_pacticipant_by_name name
         webhook_service.delete_all_webhhook_related_objects_by_pacticipant(pacticipant)
         pacticipant.destroy
diff --git a/lib/pact_broker/test/http_test_data_builder.rb b/lib/pact_broker/test/http_test_data_builder.rb
index a116d6c0d..53367c3d3 100644
--- a/lib/pact_broker/test/http_test_data_builder.rb
+++ b/lib/pact_broker/test/http_test_data_builder.rb
@@ -62,7 +62,7 @@ def deploy_to_prod(pacticipant:, version:)
 
       def create_pacticipant(name)
         puts "Creating pacticipant with name #{name}"
-        client.post("pacticipants", { name: name}).tap { |response| check_for_error(response) }
+        client.post("pacticipants", { name: name }).tap { |response| check_for_error(response) }
         separate
         self
       end
diff --git a/lib/pact_broker/test/test_data_builder.rb b/lib/pact_broker/test/test_data_builder.rb
index c86be3b1b..a53c5dfa0 100644
--- a/lib/pact_broker/test/test_data_builder.rb
+++ b/lib/pact_broker/test/test_data_builder.rb
@@ -127,7 +127,9 @@ def create_tag_with_hierarchy pacticipant_name, pacticipant_version, tag_name
 
       def create_pacticipant pacticipant_name, params = {}
         params.delete(:comment)
-        @pacticipant = PactBroker::Domain::Pacticipant.create({ :name => pacticipant_name, repository_url: "https://github.com/example-organization/#{pacticipant_name}" }.merge(params))
+        repository_url = "https://github.com/#{params[:repository_namespace] || "example-organization"}/#{params[:repository_name] || pacticipant_name}"
+        merged_params = { name: pacticipant_name, repository_url: repository_url }.merge(params)
+        @pacticipant = PactBroker::Domain::Pacticipant.create(merged_params)
         self
       end
 
diff --git a/spec/features/create_pacticipant_spec.rb b/spec/features/create_pacticipant_spec.rb
index f3d191047..9a3ccaa03 100644
--- a/spec/features/create_pacticipant_spec.rb
+++ b/spec/features/create_pacticipant_spec.rb
@@ -1,12 +1,18 @@
-require 'support/test_data_builder'
-
 describe "Creating a pacticipant" do
   let(:path) { "/pacticipants" }
   let(:headers) { {'CONTENT_TYPE' => 'application/json'} }
   let(:response_body) { JSON.parse(last_response.body, symbolize_names: true)}
-  let(:pacticipant_hash) { { name: 'Foo Thing' } }
+  let(:pacticipant_hash) do
+    {
+      name: 'Foo Thing',
+      mainDevelopmentBranches: ["main"],
+      repositoryUrl: "http://url",
+      repositoryName: "foo-thing",
+      repositoryNamespace: "some-group"
+    }
+  end
 
-  subject { post path, pacticipant_hash.to_json, headers; last_response }
+  subject { post(path, pacticipant_hash.to_json, headers) }
 
   it "returns a 201 response" do
     subject
diff --git a/spec/features/update_pacticipant_spec.rb b/spec/features/update_pacticipant_spec.rb
index 361623011..67d6b73c5 100644
--- a/spec/features/update_pacticipant_spec.rb
+++ b/spec/features/update_pacticipant_spec.rb
@@ -1,23 +1,70 @@
-describe "Publishing a pact" do
+describe "Update a pacticipant" do
 
   let(:request_body) { {'repositoryUrl' => 'http://foo'} }
   let(:path) { "/pacticipants/Some%20Consumer" }
-  let(:response_body_json) { JSON.parse(subject.body) }
+  let(:response_body_hash) { JSON.parse(subject.body, symbolize_names: true) }
 
-  subject { patch path, request_body.to_json, {'CONTENT_TYPE' => 'application/json' }; last_response  }
+  context "with a PUT" do
+    let(:request_body_hash) do
+      {
+        repositoryUrl: "http://foo",
+        repositoryName: "name",
+        repositoryNamespace: "org",
+        mainDevelopmentBranches: ["main"]
+      }
+    end
+
+    subject { put(path, request_body_hash.to_json, {'CONTENT_TYPE' => 'application/json' }) }
+
+    context "when the pacticipant exists" do
+      before do
+        td.create_pacticipant("Some Consumer")
+      end
 
-  context "when the pacticipant exists" do
+      it { is_expected.to be_a_hal_json_success_response }
 
-    before do
-      TestDataBuilder.new.create_pacticipant("Some Consumer")
+      it "updates the properties" do
+        expect(response_body_hash).to include(request_body_hash)
+      end
+
+      context "with only some of the properties set" do
+        let(:request_body_hash) do
+          {
+            repositoryUrl: "http://foo",
+          }
+        end
+
+        it "blanks out the missing ones" do
+          expect(response_body_hash[:repositoryName]).to be nil
+        end
+      end
     end
-    it "returns a 200 OK" do
-      puts subject.body unless subject.status == 200
-      expect(subject.status).to be 200
+
+    context "when the pacticipant does not exist" do
+      it { is_expected.to be_a_404_response }
     end
+  end
+
+  context "with a PATCH" do
+    subject { patch(path, request_body.to_json, {'CONTENT_TYPE' => 'application/json' })  }
+
+    context "when the pacticipant exists" do
+      before do
+        td.create_pacticipant("Some Consumer", repository_name: "existing")
+      end
+
+      it "returns a 200 OK" do
+        puts subject.body unless subject.status == 200
+        expect(subject.status).to be 200
+      end
+
+      it "leaves any existing properties that were not defined" do
+        expect(response_body_hash[:repositoryName]).to eq "existing"
+      end
 
-    it "returns a json body with the updated pacticipant" do
-      expect(subject.headers['Content-Type']).to eq "application/hal+json;charset=utf-8"
+      it "returns a json body with the updated pacticipant" do
+        expect(subject.headers['Content-Type']).to eq "application/hal+json;charset=utf-8"
+      end
     end
   end
 end
diff --git a/spec/lib/pact_broker/api/contracts/pacticipant_schema_spec.rb b/spec/lib/pact_broker/api/contracts/pacticipant_schema_spec.rb
new file mode 100644
index 000000000..87a6b3e3c
--- /dev/null
+++ b/spec/lib/pact_broker/api/contracts/pacticipant_schema_spec.rb
@@ -0,0 +1,46 @@
+require 'pact_broker/api/contracts/pacticipant_schema'
+
+module PactBroker
+  module Api
+    module Contracts
+      describe PacticipantSchema do
+        let(:params) do
+          {
+            name: "pact-broker",
+            displayName: "Pact Broker",
+            mainDevelopmentBranches: branches,
+            repositoryUrl: "https://github.com/pact-foundation/pact_broker",
+            repositoryName: "pact_broker",
+            repositoryNamespace: "pact-foundation"
+          }
+        end
+
+        let(:branches) { ["main"] }
+
+        subject { PacticipantSchema.call(params) }
+
+        context "with valid params" do
+          it { is_expected.to be_empty }
+        end
+
+        context "with empty params" do
+          let(:params) do
+            {
+              repositoryUrl: "",
+              repositoryName: "",
+              repositoryNamespace: ""
+            }
+          end
+
+          it { is_expected.to be_empty }
+        end
+
+        context "with branch names that contain spaces" do
+          let(:branches) { ["main foo"] }
+
+          its([:mainDevelopmentBranches, 0]) { is_expected.to include "cannot contain spaces" }
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/pact_broker/api/decorators/pacticipant_decorator_spec.rb b/spec/lib/pact_broker/api/decorators/pacticipant_decorator_spec.rb
index 8f95d69c5..9ed455368 100644
--- a/spec/lib/pact_broker/api/decorators/pacticipant_decorator_spec.rb
+++ b/spec/lib/pact_broker/api/decorators/pacticipant_decorator_spec.rb
@@ -3,71 +3,82 @@
 require 'pact_broker/domain/pacticipant'
 
 module PactBroker
-
   module Api
-
     module Decorators
-
       describe PacticipantDecorator do
+        describe "from_json" do
+          let(:pacticipant) { OpenStruct.new }
+          let(:decorator) { PacticipantDecorator.new(pacticipant) }
+          let(:hash) do
+            {
+              name: "Foo",
+              mainDevelopmentBranches: ["main"]
+            }
+          end
 
-        let(:test_data_builder) { TestDataBuilder.new }
-        let(:pacticipant) do
-          test_data_builder
-            .create_pacticipant('Name')
-            .create_label('foo')
-            .and_return(:pacticipant)
-        end
-
-        let(:created_at) { Time.new(2014, 3, 4) }
-        let(:updated_at) { Time.new(2014, 3, 5) }
-        let(:base_url) { 'http://example.org' }
+          subject { decorator.from_json(hash.to_json) }
 
-        before do
-          pacticipant.created_at = created_at
-          pacticipant.updated_at = updated_at
-          allow_any_instance_of(PacticipantDecorator).to receive(:templated_tag_url_for_pacticipant).and_return('version_tag_url')
+          its(:name) { is_expected.to eq "Foo" }
+          its(:main_development_branches) { is_expected.to eq ["main"] }
         end
+        describe "to_json" do
+          let(:pacticipant) do
+            td.create_pacticipant('Name')
+              .create_label('foo')
+              .and_return(:pacticipant)
+          end
 
-        subject { JSON.parse PacticipantDecorator.new(pacticipant).to_json(user_options: {base_url: base_url}), symbolize_names: true }
+          let(:created_at) { Time.new(2014, 3, 4) }
+          let(:updated_at) { Time.new(2014, 3, 5) }
+          let(:base_url) { 'http://example.org' }
 
-        it "includes timestamps" do
-          expect(subject[:createdAt]).to eq FormatDateTime.call(created_at)
-          expect(subject[:updatedAt]).to eq FormatDateTime.call(updated_at)
-        end
+          before do
+            pacticipant.created_at = created_at
+            pacticipant.updated_at = updated_at
+            allow_any_instance_of(PacticipantDecorator).to receive(:templated_tag_url_for_pacticipant).and_return('version_tag_url')
+          end
 
-        it "includes embedded labels" do
-          expect(subject[:_embedded][:labels].first).to include name: 'foo'
-          expect(subject[:_embedded][:labels].first[:_links][:self][:href]).to match %r{http://example.org/.*foo}
-        end
+          subject { JSON.parse PacticipantDecorator.new(pacticipant).to_json(user_options: { base_url: base_url }), symbolize_names: true }
 
-        it "creates the URL for a version tag" do
-          expect_any_instance_of(PacticipantDecorator).to receive(:templated_tag_url_for_pacticipant).with("Name", base_url)
-          subject
-        end
+          it "includes timestamps" do
+            expect(subject[:createdAt]).to eq FormatDateTime.call(created_at)
+            expect(subject[:updatedAt]).to eq FormatDateTime.call(updated_at)
+          end
 
-        it "includes a relation for a version tag" do
-          expect(subject[:_links][:'pb:version-tag'][:href]).to eq "version_tag_url"
-        end
+          it "includes embedded labels" do
+            expect(subject[:_embedded][:labels].first).to include name: 'foo'
+            expect(subject[:_embedded][:labels].first[:_links][:self][:href]).to match %r{http://example.org/.*foo}
+          end
 
-        context "when there is a latest_version" do
-          before { test_data_builder.create_version("1.2.107") }
-          it "includes an embedded latestVersion" do
-            expect(subject[:_embedded][:latestVersion]).to include number: "1.2.107"
+          it "creates the URL for a version tag" do
+            expect_any_instance_of(PacticipantDecorator).to receive(:templated_tag_url_for_pacticipant).with("Name", base_url)
+            subject
           end
 
-          it "includes an embedded latest-version for backwards compatibility" do
-            expect(subject[:_embedded][:'latest-version']).to include number: "1.2.107"
+          it "includes a relation for a version tag" do
+            expect(subject[:_links][:'pb:version-tag'][:href]).to eq "version_tag_url"
           end
 
-          it "includes a deprecation warning" do
-            expect(subject[:_embedded][:'latest-version']).to include title: "DEPRECATED - please use latestVersion"
+          context "when there is a latest_version" do
+            before { td.create_version("1.2.107") }
+            it "includes an embedded latestVersion" do
+              expect(subject[:_embedded][:latestVersion]).to include number: "1.2.107"
+            end
+
+            it "includes an embedded latest-version for backwards compatibility" do
+              expect(subject[:_embedded][:'latest-version']).to include number: "1.2.107"
+            end
+
+            it "includes a deprecation warning" do
+              expect(subject[:_embedded][:'latest-version']).to include title: "DEPRECATED - please use latestVersion"
+            end
           end
-        end
 
-        context "when there is no latest_version" do
-          it "doesn't blow up" do
-            expect(subject[:_embedded]).to_not have_key(:latestVersion)
-            expect(subject[:_embedded]).to_not have_key(:'latest-version')
+          context "when there is no latest_version" do
+            it "doesn't blow up" do
+              expect(subject[:_embedded]).to_not have_key(:latestVersion)
+              expect(subject[:_embedded]).to_not have_key(:'latest-version')
+            end
           end
         end
       end
diff --git a/spec/lib/pact_broker/api/resources/pacticipant_spec.rb b/spec/lib/pact_broker/api/resources/pacticipant_spec.rb
index e388726fa..372ce681a 100644
--- a/spec/lib/pact_broker/api/resources/pacticipant_spec.rb
+++ b/spec/lib/pact_broker/api/resources/pacticipant_spec.rb
@@ -2,11 +2,8 @@
 require 'pact_broker/api/resources/pacticipant'
 
 module PactBroker::Api
-
   module Resources
-
     describe Pacticipant do
-
       describe "DELETE" do
 
         let(:pacticpant) { double("pacticpant") }
diff --git a/spec/lib/pact_broker/api/resources/pacticipants_spec.rb b/spec/lib/pact_broker/api/resources/pacticipants_spec.rb
index cf289bc97..8cacf2562 100644
--- a/spec/lib/pact_broker/api/resources/pacticipants_spec.rb
+++ b/spec/lib/pact_broker/api/resources/pacticipants_spec.rb
@@ -4,31 +4,29 @@
 module PactBroker
   module Api
     module Resources
-
       describe Pacticipants do
-
         describe "POST" do
-          let(:params) { {name: 'New Consumer'} }
-          let(:json) { params.to_json }
-          let(:model) { instance_double(model_class, validate: errors) }
+          let(:params) { { name: 'New Consumer' } }
+          let(:request_body) { params.to_json }
           let(:created_model) { instance_double(model_class) }
-          let(:errors) { [] }
+          let(:errors) { {} }
           let(:model_class) { PactBroker::Domain::Pacticipant }
           let(:decorator_class) { PactBroker::Api::Decorators::PacticipantDecorator }
-          let(:decorator) { instance_double(decorator_class, to_json: response_json, from_json: model) }
+          let(:parsed_model) { OpenStruct.new(name: "New Consumer") }
+          let(:decorator) { instance_double(decorator_class, to_json: response_json, from_json: parsed_model) }
           let(:response_json) { {some: 'json'}.to_json }
+          let(:schema) { PactBroker::Api::Contracts::PacticipantSchema }
 
           before do
-            allow(model_class).to receive(:new).and_return(model)
             allow(PactBroker::Pacticipants::Service).to receive(:create).and_return(created_model)
-            allow(decorator_class).to receive(:new).with(model).and_return(decorator)
-            allow(decorator_class).to receive(:new).with(created_model).and_return(decorator)
+            allow(decorator_class).to receive(:new).and_return(decorator)
+            allow(schema).to receive(:call).and_return(errors)
           end
 
-          subject { post "/pacticipants", json, 'CONTENT_TYPE' => 'application/json' }
+          subject { post "/pacticipants", request_body, 'CONTENT_TYPE' => 'application/json' }
 
           context "structurally incorrect JSON" do
-            let(:json) { "{" }
+            let(:request_body) { "{" }
 
             it "returns a 400" do
               subject
@@ -37,7 +35,7 @@ module Resources
           end
 
           context "when the model is invalid" do
-            let(:errors) { ['error'] }
+            let(:errors) { { "some" => ["errors"] } }
 
             it "returns a 400" do
               subject
@@ -52,7 +50,7 @@ module Resources
             end
 
             it "parses the request JSON" do
-              expect(decorator).to receive(:from_json).with(json)
+              expect(decorator).to receive(:from_json).with(request_body)
               subject
             end
 
@@ -83,9 +81,7 @@ module Resources
             end
           end
         end
-
       end
     end
-
   end
 end
diff --git a/spec/lib/pact_broker/domain/pacticipant_spec.rb b/spec/lib/pact_broker/domain/pacticipant_spec.rb
deleted file mode 100644
index 928ac37d5..000000000
--- a/spec/lib/pact_broker/domain/pacticipant_spec.rb
+++ /dev/null
@@ -1,26 +0,0 @@
-require 'spec_helper'
-require 'pact_broker/domain/pacticipant'
-
-module PactBroker
-  module Domain
-    describe Pacticipant do
-      describe "validate" do
-        context "with all valid attributes" do
-          subject { Pacticipant.new name: 'Name' }
-
-          it "returns an empty array" do
-            expect(subject.validate).to eq []
-          end
-        end
-
-        context "with no name" do
-          subject { Pacticipant.new }
-
-          it "returns an error" do
-            expect(subject.validate).to eq ["Missing required attribute 'name'"]
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/spec/lib/pact_broker/pacticipants/generate_display_name_spec.rb b/spec/lib/pact_broker/pacticipants/generate_display_name_spec.rb
new file mode 100644
index 000000000..59edbfeea
--- /dev/null
+++ b/spec/lib/pact_broker/pacticipants/generate_display_name_spec.rb
@@ -0,0 +1,39 @@
+require 'pact_broker/pacticipants/generate_display_name'
+
+module PactBroker
+  module Pacticipants
+    describe GenerateDisplayName do
+      describe ".call" do
+        TEST_CASES = {
+          "foo" => "Foo",
+          "MyService" => "My Service",
+          "my-service" => "My Service",
+          "my_service" => "My Service",
+          "my service" => "My Service",
+          "ABCService" => "ABC Service",
+          "A4Service" => "A4 Service",
+          "SNSPactEventConsumer" => "SNS Pact Event Consumer",
+          "AWSSummiteerWeb" => "AWS Summiteer Web",
+          "Beer-Consumer" => "Beer Consumer",
+          "foo.pretend-consumer" => "Foo Pretend Consumer",
+          "Client-XX" => "Client XX",
+          "providerJSWorkshop" => "Provider JS Workshop",
+          "e2e Provider Example" => "E2e Provider Example",
+          "MP - Our Provider" => "MP - Our Provider",
+          "PoC - Pact-broker-consumer" => "PoC - Pact Broker Consumer",
+          "QB-DATABASE Service" => "QB DATABASE Service",
+          "Support Species App (Provider)" => "Support Species App (Provider)",
+          9 => "9",
+          "" => "",
+          nil => nil
+        }
+
+        TEST_CASES.each do | name, expected_display_name |
+          it "converts #{name.inspect} to #{expected_display_name.inspect}" do
+            expect(GenerateDisplayName.call(name)).to eq expected_display_name
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/pact_broker/pacticipants/repository_spec.rb b/spec/lib/pact_broker/pacticipants/repository_spec.rb
index 0e1845a6b..d981db75c 100644
--- a/spec/lib/pact_broker/pacticipants/repository_spec.rb
+++ b/spec/lib/pact_broker/pacticipants/repository_spec.rb
@@ -12,20 +12,34 @@ module Pacticipants
 
         context "when the pacticipant does not already exist" do
           before do
-            TestDataBuilder.new.create_pacticipant("Bar")
+            td.create_pacticipant("Bar")
+            allow_any_instance_of(PactBroker::Domain::Pacticipant).to receive(:generate_display_name).and_return("display_name")
           end
 
-          subject { repository.create(name: "Foo") }
+          let(:display_name) { "Foo" }
+
+          subject { repository.create(name: "foo", display_name: display_name, repository_url: "url", main_development_branches: ["main"]) }
 
           it "returns the new pacticipant" do
             expect(subject).to be_a(PactBroker::Domain::Pacticipant)
-            expect(subject.name).to eq "Foo"
+            expect(subject.name).to eq "foo"
+            expect(subject.main_development_branches).to eq ["main"]
+            expect(subject.repository_url).to eq "url"
+            expect(subject.display_name).to eq "Foo"
+          end
+
+          context "when no display name is provided" do
+            let(:display_name) { nil }
+
+            it "generates one" do
+              expect(subject.display_name).to eq "display_name"
+            end
           end
         end
 
         context "when a race condition occurs and the pacticipant was already created by another request" do
           before do
-            TestDataBuilder.new.create_pacticipant("Foo")
+            td.create_pacticipant("Foo", repository_url: "original")
           end
 
           it "does not raise an error" do
@@ -35,13 +49,29 @@ module Pacticipants
           it "returns the existing pacticipant" do
             expect(subject).to be_a(PactBroker::Domain::Pacticipant)
             expect(subject.name).to eq "Foo"
+            expect(subject.repository_url).to eq "original"
           end
         end
       end
 
+      describe "replace" do
+        before do
+          td.create_pacticipant("Bar", main_development_branches: ["foo"], repository_namespace: "foo")
+          allow_any_instance_of(PactBroker::Domain::Pacticipant).to receive(:generate_display_name).and_return("display_name")
+        end
+
+        subject { Repository.new.replace("Bar", OpenStruct.new(main_development_branches: ["bar"], repository_url: "new_url")) }
+
+        it "replaces the pacticipant" do
+          expect(subject.main_development_branches).to eq ["bar"]
+          expect(subject.repository_namespace).to eq nil
+          expect(subject.display_name).to eq "display_name"
+        end
+      end
+
       describe "#find" do
         before do
-          TestDataBuilder.new
+          td
             .create_pacticipant("Foo")
             .create_label("in")
             .create_pacticipant("Bar")
@@ -124,9 +154,8 @@ module Pacticipants
       end
 
       describe "#pacticipant_names" do
-
         before do
-          TestDataBuilder.new
+          td
             .create_pacticipant("Plants")
             .create_pacticipant("Animals")
         end
@@ -141,7 +170,7 @@ module Pacticipants
 
       describe "#find_all_pacticipant_versions_in_reverse_order" do
         before do
-          TestDataBuilder.new
+          td
             .create_consumer("Foo")
             .create_consumer_version("1.2.3")
             .create_consumer_version("4.5.6")
diff --git a/spec/lib/pact_broker/pacticipants/service_spec.rb b/spec/lib/pact_broker/pacticipants/service_spec.rb
index a033eeaff..34124a4e8 100644
--- a/spec/lib/pact_broker/pacticipants/service_spec.rb
+++ b/spec/lib/pact_broker/pacticipants/service_spec.rb
@@ -15,20 +15,6 @@ module Pacticipants
 
       subject{ Service }
 
-      describe ".update" do
-        before do
-          td.create_pacticipant("Foo")
-        end
-
-        let(:params) { { 'name' => 'Foo', 'repositoryUrl' => 'http://foo' } }
-
-        subject { Service.update(params) }
-
-        it "updates the repositoryUrl" do
-          expect(subject.repository_url).to eq 'http://foo'
-        end
-      end
-
       describe ".messages_for_potential_duplicate_pacticipants" do
 
         let(:base_url) { 'http://example.org' }