diff --git a/lib/pact/provider/generator/boolean.rb b/lib/pact/provider/generator/boolean.rb
new file mode 100644
index 00000000..499e326a
--- /dev/null
+++ b/lib/pact/provider/generator/boolean.rb
@@ -0,0 +1,16 @@
+module Pact
+  module Provider
+    module Generator
+      # Boolean provides the boolean generator which will give a true or false value
+      class Boolean
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == 'Boolean'
+        end
+
+        def call(_hash, _params = nil, _example_value = nil)
+          [true, false].sample
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/date.rb b/lib/pact/provider/generator/date.rb
new file mode 100644
index 00000000..7b05c247
--- /dev/null
+++ b/lib/pact/provider/generator/date.rb
@@ -0,0 +1,64 @@
+require 'date'
+
+module Pact
+  module Provider
+    module Generator
+      # Date provides the time generator which will give the current date in the defined format
+      class Date
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == type
+        end
+
+        def call(hash, _params = nil, _example_value = nil)
+          format = hash['format'] || default_format
+          ::Time.now.strftime(convert_from_java_simple_date_format(format))
+        end
+
+        def type
+          'Date'
+        end
+
+        def default_format
+          'yyyy-MM-dd'
+        end
+
+        # Format for the pact specficiation should be the Java DateTimeFormmater
+        # This tries to convert to something Ruby can format.
+        def convert_from_java_simple_date_format(format)
+          # Year
+          format.sub!(/(?<!%)y{4,}/, '%Y')
+          format.sub!(/(?<!%)y{1,}/, '%y')
+
+          # Month
+          format.sub!(/(?<!%)M{4,}/, '%B')
+          format.sub!(/(?<!%)M{3}/, '%b')
+          format.sub!(/(?<!%)M{1,2}/, '%m')
+
+          # Week
+          format.sub!(/(?<!%)M{1,}/, '%W')
+
+          # Day
+          format.sub!(/(?<!%)D{1,}/, '%j')
+          format.sub!(/(?<!%)d{1,}/, '%d')
+          format.sub!(/(?<!%)E{4,}/, '%A')
+          format.sub!(/(?<!%)D{1,}/, '%a')
+          format.sub!(/(?<!%)u{1,}/, '%u')
+
+          # Time
+          format.sub!(/(?<!%)a{1,}/, '%p')
+          format.sub!(/(?<!%)k{1,}/, '%H')
+          format.sub!(/(?<!%)n{1,}/, '%M')
+          format.sub!(/(?<!%)s{1,}/, '%S')
+          format.sub!(/(?<!%)S{1,}/, '%L')
+
+          # Timezone
+          format.sub!(/(?<!%)z{1,}/, '%z')
+          format.sub!(/(?<!%)Z{1,}/, '%z')
+          format.sub!(/(?<!%)X{1,}/, '%Z')
+
+          format
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/datetime.rb b/lib/pact/provider/generator/datetime.rb
new file mode 100644
index 00000000..6b12313c
--- /dev/null
+++ b/lib/pact/provider/generator/datetime.rb
@@ -0,0 +1,18 @@
+require 'date'
+
+module Pact
+  module Provider
+    module Generator
+      # DateTime provides the time generator which will give the current date time in the defined format
+      class DateTime < Date
+        def type
+          'DateTime'
+        end
+
+        def default_format
+          'yyyy-MM-dd HH:mm'
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/provider_state.rb b/lib/pact/provider/generator/provider_state.rb
new file mode 100644
index 00000000..4ed56766
--- /dev/null
+++ b/lib/pact/provider/generator/provider_state.rb
@@ -0,0 +1,57 @@
+require 'pact/logging'
+
+module Pact
+  module Provider
+    module Generator
+      # ProviderState provides the provider state generator which will inject
+      # values provided by the provider state setup url.
+      class ProviderState
+        include Pact::Logging
+
+        # rewrite of https://github.com/DiUS/pact-jvm/blob/master/core/support/src/main/kotlin/au/com/dius/pact/core/support/expressions/ExpressionParser.kt#L27
+        VALUES_SEPARATOR = ','
+        START_EXPRESSION = "\${"
+        END_EXPRESSION = '}'
+
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == 'ProviderState'
+        end
+
+        def call(hash, params = nil, _example_value = nil)
+          params ||= {}
+          parse_expression hash['expression'], params
+        end
+
+        def parse_expression(expression, params)
+          return_string = []
+          buffer = expression
+          # initial value
+          position = buffer.index(START_EXPRESSION)
+
+          while position && position >= 0
+            if position.positive?
+              # add string
+              return_string.push(buffer[0...position])
+            end
+            end_position = buffer.index(END_EXPRESSION, position)
+            raise 'Missing closing brace in expression string' if !end_position || end_position.negative?
+
+            variable = buffer[position + 2...end_position]
+
+            if !params[variable]
+              logger.info "Could not subsitute provider state key #{variable}, have #{params}"
+            end
+
+            expression = params[variable] || ''
+            return_string.push(expression)
+
+            buffer = buffer[end_position + 1...-1]
+            position = buffer.index(START_EXPRESSION)
+          end
+
+          return_string.join('')
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/random_decimal.rb b/lib/pact/provider/generator/random_decimal.rb
new file mode 100644
index 00000000..5a756552
--- /dev/null
+++ b/lib/pact/provider/generator/random_decimal.rb
@@ -0,0 +1,39 @@
+require 'bigdecimal'
+
+module Pact
+  module Provider
+    module Generator
+      # RandomDecimal provides the random decimal generator which will generate a decimal value of digits length
+      class RandomDecimal
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == 'RandomDecimal'
+        end
+
+        def call(hash, _params = nil, _example_value = nil)
+          digits = hash['digits'] || 6
+
+          raise 'RandomDecimalGenerator digits must be > 0, got $digits' if digits < 1
+
+          return rand(0..9) if digits == 1
+
+          return rand(0..9) + rand(1..9) / 10 if digits == 2
+
+          pos = rand(1..digits - 1)
+          precision = digits - pos
+          integers = ''
+          decimals = ''
+          while pos.positive?
+            integers += String(rand(1..9))
+            pos -= 1
+          end
+          while precision.positive?
+            decimals += String(rand(1..9))
+            precision -= 1
+          end
+
+          Float("#{integers}.#{decimals}")
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/random_hexadecimal.rb b/lib/pact/provider/generator/random_hexadecimal.rb
new file mode 100644
index 00000000..f2e4f4db
--- /dev/null
+++ b/lib/pact/provider/generator/random_hexadecimal.rb
@@ -0,0 +1,21 @@
+require 'securerandom'
+
+module Pact
+  module Provider
+    module Generator
+      # RandomHexadecimal provides the random hexadecimal generator which will generate a hexadecimal
+      class RandomHexadecimal
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == 'RandomHexadecimal'
+        end
+
+        def call(hash, _params = nil, _example_value = nil)
+          digits = hash['digits'] || 8
+          bytes = (digits / 2).ceil
+          string = SecureRandom.hex(bytes)
+          string[0, digits]
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/random_int.rb b/lib/pact/provider/generator/random_int.rb
new file mode 100644
index 00000000..5f749359
--- /dev/null
+++ b/lib/pact/provider/generator/random_int.rb
@@ -0,0 +1,18 @@
+module Pact
+  module Provider
+    module Generator
+      # RandomInt provides the random int generator which generate a random integer, with a min/max
+      class RandomInt
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == 'RandomInt'
+        end
+
+        def call(hash, _params = nil, _example_value = nil)
+          min = hash['min'] || 0
+          max = hash['max'] || 2_147_483_647
+          rand(min..max)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/random_string.rb b/lib/pact/provider/generator/random_string.rb
new file mode 100644
index 00000000..5c56b08d
--- /dev/null
+++ b/lib/pact/provider/generator/random_string.rb
@@ -0,0 +1,18 @@
+module Pact
+  module Provider
+    module Generator
+      # RandomString provides the random string generator which generate a random string of size length
+      class RandomString
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == 'RandomString'
+        end
+
+        def call(hash, _params = nil, _example_value = nil)
+          size = hash['size'] || 20
+          string = rand(36**(size + 2)).to_s(36)
+          string[0, size]
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/regex.rb b/lib/pact/provider/generator/regex.rb
new file mode 100644
index 00000000..1415cf87
--- /dev/null
+++ b/lib/pact/provider/generator/regex.rb
@@ -0,0 +1,19 @@
+require 'string_pattern'
+
+module Pact
+  module Provider
+    module Generator
+      # Regex provides the regex generator which will generate a value based on the regex pattern provided
+      class Regex
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == 'Regex'
+        end
+
+        def call(hash, _params = nil, _example_value = nil)
+          pattern = hash['pattern'] || ''
+          StringPattern.generate(Regexp.new(pattern))
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/time.rb b/lib/pact/provider/generator/time.rb
new file mode 100644
index 00000000..0db4d214
--- /dev/null
+++ b/lib/pact/provider/generator/time.rb
@@ -0,0 +1,18 @@
+require 'date'
+
+module Pact
+  module Provider
+    module Generator
+      # Time provides the time generator which will give the current time in the defined format
+      class Time < Date
+        def type
+          'Time'
+        end
+
+        def default_format
+          'HH:mm'
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generator/uuid.rb b/lib/pact/provider/generator/uuid.rb
new file mode 100644
index 00000000..f1441340
--- /dev/null
+++ b/lib/pact/provider/generator/uuid.rb
@@ -0,0 +1,21 @@
+require 'securerandom'
+
+module Pact
+  module Provider
+    module Generator
+      # Uuid provides the uuid generator
+      class Uuid
+        def can_generate?(hash)
+          hash.key?('type') && hash['type'] == 'Uuid'
+        end
+
+        # If we had the example value, we could determine what type of uuid
+        # to send, this is what pact-jvm does
+        # See https://github.com/pact-foundation/pact-jvm/blob/master/core/model/src/main/kotlin/au/com/dius/pact/core/model/generators/Generator.kt
+        def call(_hash, _params = nil, _example_value = nil)
+          SecureRandom.uuid
+        end
+      end
+    end
+  end
+end
diff --git a/lib/pact/provider/generators.rb b/lib/pact/provider/generators.rb
new file mode 100644
index 00000000..2cd77cdb
--- /dev/null
+++ b/lib/pact/provider/generators.rb
@@ -0,0 +1,66 @@
+require 'pact/provider/generator/boolean'
+require 'pact/provider/generator/date'
+require 'pact/provider/generator/datetime'
+require 'pact/provider/generator/provider_state'
+require 'pact/provider/generator/random_decimal'
+require 'pact/provider/generator/random_hexadecimal'
+require 'pact/provider/generator/random_int'
+require 'pact/provider/generator/random_string'
+require 'pact/provider/generator/regex'
+require 'pact/provider/generator/time'
+require 'pact/provider/generator/uuid'
+require 'pact/matching_rules/jsonpath'
+require 'pact/matching_rules/v3/extract'
+require 'jsonpath'
+
+module Pact
+  module Provider
+    class Generators
+      def self.add_generator(generator)
+        generators.unshift(generator)
+      end
+
+    def self.generators
+        @generators ||= []
+      end
+
+      def self.execute_generators(object, state_params = nil, example_value = nil)
+        generators.each do |parser|
+          return parser.call(object, state_params, example_value) if parser.can_generate?(object)
+        end
+
+        raise Pact::UnrecognizePactFormatError, "This document does not use a recognised Pact generator: #{object}"
+      end
+
+      def self.apply_generators(expected_request, component, example_value, state_params)
+        # Latest pact-support is required to have generators exposed
+        if expected_request.methods.include?(:generators) && expected_request.generators[component]
+          # Some component will have single generator without selectors, i.e. path
+          generators = expected_request.generators[component]
+          if generators.is_a?(Hash) && generators.key?('type')
+            return execute_generators(generators, state_params, example_value)
+          end
+
+          generators.each do |selector, generator|
+            val = JsonPath.new(selector).on(example_value)
+            replace = execute_generators(generator, state_params, val)
+            example_value = JsonPath.for(example_value).gsub(selector) { |_v| replace }.to_hash
+          end
+        end
+        example_value
+      end
+
+      add_generator(Generator::Boolean.new)
+      add_generator(Generator::Date.new)
+      add_generator(Generator::DateTime.new)
+      add_generator(Generator::ProviderState.new)
+      add_generator(Generator::RandomDecimal.new)
+      add_generator(Generator::RandomHexadecimal.new)
+      add_generator(Generator::RandomInt.new)
+      add_generator(Generator::RandomString.new)
+      add_generator(Generator::Regex.new)
+      add_generator(Generator::Time.new)
+      add_generator(Generator::Uuid.new)
+    end
+  end
+end
diff --git a/lib/pact/provider/request.rb b/lib/pact/provider/request.rb
index ad4b1998..561e24a6 100644
--- a/lib/pact/provider/request.rb
+++ b/lib/pact/provider/request.rb
@@ -1,6 +1,7 @@
 require 'json'
 require 'pact/reification'
 require 'pact/shared/null_expectation'
+require 'pact/provider/generators'
 
 module Pact
   module Provider
@@ -10,8 +11,9 @@ class Replayable
         # See https://github.com/rack/rack/blob/e7d741c6282ca4cf4e01506f5681e6e6b14c0b32/SPEC#L87-89
         NO_HTTP_PREFIX = ["CONTENT-TYPE", "CONTENT-LENGTH"]
 
-        def initialize expected_request
+        def initialize expected_request, state_params = nil
           @expected_request = expected_request
+          @state_params = state_params
         end
 
         def method
@@ -19,7 +21,7 @@ def method
         end
 
         def path
-          expected_request.full_path
+          Pact::Provider::Generators.apply_generators(expected_request, "path", expected_request.full_path, @state_params)
         end
 
         def body
@@ -27,17 +29,20 @@ def body
           when String then expected_request.body
           when NullExpectation then ''
           else
-            reified_body
+            Pact::Provider::Generators.apply_generators(expected_request, "body", reified_body, @state_params)
           end
         end
 
         def headers
           request_headers = {}
           return request_headers if expected_request.headers.is_a?(Pact::NullExpectation)
+
           expected_request.headers.each do |key, value|
-            request_headers[rack_request_header_for(key)] = Pact::Reification.from_term(value)
+            request_headers[key] = Pact::Reification.from_term(value)
           end
-          request_headers
+
+          request_headers = Pact::Provider::Generators.apply_generators(expected_request, "header", request_headers, @state_params)
+          request_headers.map{ |key,value| [rack_request_header_for(key), value]}.to_h
         end
 
         private
diff --git a/lib/pact/provider/rspec.rb b/lib/pact/provider/rspec.rb
index a6e7372c..b498def5 100644
--- a/lib/pact/provider/rspec.rb
+++ b/lib/pact/provider/rspec.rb
@@ -25,6 +25,7 @@ def honour_pactfile pact_source, pact_json, options
           pact_uri = pact_source.uri
           Pact.configuration.output_stream.puts "INFO: Reading pact at #{pact_uri}"
           consumer_contract = Pact::ConsumerContract.from_json(pact_json)
+
           suffix = pact_uri.metadata[:pending] ? " [PENDING]": ""
           example_group_description = "Verifying a pact between #{consumer_contract.consumer.name} and #{consumer_contract.provider.name}#{suffix}"
           example_group_metadata = { pactfile_uri: pact_uri, pact_criteria: options[:criteria] }
@@ -77,7 +78,6 @@ def describe_interaction_with_provider_state interaction, options
         end
 
         def describe_interaction interaction, options
-
           # pact_uri and pact_interaction are used by
           # Pact::Provider::RSpec::PactBrokerFormatter
 
@@ -103,8 +103,9 @@ def describe_interaction interaction, options
             before do | example |
               interaction_context.run_once :before do
                 Pact.configuration.logger.info "Running example '#{Pact::RSpec.full_description(example)}'"
-                set_up_provider_states interaction.provider_states, options[:consumer]
-                replay_interaction interaction, options[:request_customizer]
+                provider_states_result = set_up_provider_states interaction.provider_states, options[:consumer]
+                state_params = provider_states_result[interaction.provider_state];
+                replay_interaction interaction, options[:request_customizer], state_params
                 interaction_context.last_response = last_response
               end
             end
@@ -129,6 +130,7 @@ def describe_message expected_response, interaction_context
           include Pact::RSpec::Matchers
           extend Pact::Matchers::Messages
 
+
           let(:expected_contents) { expected_response.body[:contents].as_json }
           let(:response) { interaction_context.last_response }
           let(:differ) { Pact.configuration.body_differ_for_content_type diff_content_type }
diff --git a/lib/pact/provider/test_methods.rb b/lib/pact/provider/test_methods.rb
index f27466af..1619633d 100644
--- a/lib/pact/provider/test_methods.rb
+++ b/lib/pact/provider/test_methods.rb
@@ -14,8 +14,8 @@ module TestMethods
       include Pact::Logging
       include Rack::Test::Methods
 
-      def replay_interaction interaction, request_customizer = nil
-        request = Request::Replayable.new(interaction.request)
+      def replay_interaction interaction, request_customizer = nil, state_params = nil
+        request = Request::Replayable.new(interaction.request, state_params)
         request = request_customizer.call(request, interaction) if request_customizer
         args = [request.path, request.body, request.headers]
 
@@ -42,11 +42,17 @@ def parse_body_from_response rack_response
       end
 
       def set_up_provider_states provider_states, consumer, options = {}
+        provider_states_result = {};
         # If there are no provider state, execute with an nil state to ensure global and base states are executed
         Pact.configuration.provider_state_set_up.call(nil, consumer, options) if provider_states.nil? || provider_states.empty?
         provider_states.each do | provider_state |
-          Pact.configuration.provider_state_set_up.call(provider_state.name, consumer, options.merge(params: provider_state.params))
+          result = Pact.configuration.provider_state_set_up.call(provider_state.name, consumer, options.merge(params: provider_state.params))
+          if result.is_a?(Hash)
+            provider_states_result[provider_state.name] = result
+          end
         end
+
+        provider_states_result
       end
 
       def tear_down_provider_states provider_states, consumer, options = {}
diff --git a/pact.gemspec b/pact.gemspec
index 90338cea..fdcef762 100644
--- a/pact.gemspec
+++ b/pact.gemspec
@@ -31,8 +31,10 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency 'thor', '>= 0.20', '< 2.0'
   gem.add_runtime_dependency 'webrick', '~> 1.8'
   gem.add_runtime_dependency 'term-ansicolor', '~> 1.7'
+  gem.add_runtime_dependency 'string_pattern', '~> 2.0'
+  gem.add_runtime_dependency 'jsonpath', '~> 1.0'
 
-  gem.add_runtime_dependency 'pact-support', '~> 1.16', '>= 1.16.9'
+  gem.add_runtime_dependency 'pact-support', '~> 1.19', '>= 1.19.0'
   gem.add_runtime_dependency 'pact-mock_service', '~> 3.0', '>= 3.3.1'
 
   gem.add_development_dependency 'rake', '~> 13.0'
diff --git a/spec/lib/pact/provider/generator/boolean_spec.rb b/spec/lib/pact/provider/generator/boolean_spec.rb
new file mode 100644
index 00000000..0ef0d7e0
--- /dev/null
+++ b/spec/lib/pact/provider/generator/boolean_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/provider/generator/boolean'
+
+describe Pact::Provider::Generator::Boolean do
+  generator = Pact::Provider::Generator::Boolean.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'Boolean' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'Boolean' }
+    expect(generator.call(hash)).to eq(true).or eq(false)
+  end
+end
diff --git a/spec/lib/pact/provider/generator/date_spec.rb b/spec/lib/pact/provider/generator/date_spec.rb
new file mode 100644
index 00000000..46b32d16
--- /dev/null
+++ b/spec/lib/pact/provider/generator/date_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/provider/generator/date'
+
+describe Pact::Provider::Generator::Date do
+  generator = Pact::Provider::Generator::Date.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'Date' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'Date' }
+    expect(generator.call(hash).length).to eq(10)
+  end
+end
diff --git a/spec/lib/pact/provider/generator/datetime_spec.rb b/spec/lib/pact/provider/generator/datetime_spec.rb
new file mode 100644
index 00000000..32c8c1b5
--- /dev/null
+++ b/spec/lib/pact/provider/generator/datetime_spec.rb
@@ -0,0 +1,21 @@
+require 'pact/provider/generator/datetime'
+
+describe Pact::Provider::Generator::DateTime do
+  generator = Pact::Provider::Generator::DateTime.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'DateTime' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'DateTime' }
+    p generator.call(hash)
+    expect(generator.call(hash).length).to eq(16)
+  end
+end
diff --git a/spec/lib/pact/provider/generator/provider_state_spec.rb b/spec/lib/pact/provider/generator/provider_state_spec.rb
new file mode 100644
index 00000000..3e3d4519
--- /dev/null
+++ b/spec/lib/pact/provider/generator/provider_state_spec.rb
@@ -0,0 +1,37 @@
+require 'pact/provider/generator/provider_state'
+
+describe Pact::Provider::Generator::ProviderState do
+  generator = Pact::Provider::Generator::ProviderState.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'ProviderState' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call without params' do
+    hash = { 'type' => 'ProviderState', 'expression' => 'Bearer ${access_token}' }
+    expect(generator.call(hash)).to eq 'Bearer '
+  end
+
+  it 'call with correct params' do
+    hash = { 'type' => 'ProviderState', 'expression' => 'Bearer ${access_token}' }
+    params = { 'access_token' => 'ABC' }
+    expect(generator.call(hash, params)).to eq 'Bearer ABC'
+  end
+
+  it 'call with wrong params' do
+    hash = { 'type' => 'ProviderState', 'expression' => 'Bearer ${access_token}' }
+    params = { 'refresh_token' => 'ABC' }
+    expect(generator.call(hash, params)).to eq 'Bearer '
+  end
+
+  it 'call with incomplete expression' do
+    hash = { 'type' => 'ProviderState', 'expression' => 'Bearer ${access_token' }
+    expect { generator.call(hash) }.to raise_error('Missing closing brace in expression string')
+  end
+end
diff --git a/spec/lib/pact/provider/generator/random_decimal_spec.rb b/spec/lib/pact/provider/generator/random_decimal_spec.rb
new file mode 100644
index 00000000..eb495367
--- /dev/null
+++ b/spec/lib/pact/provider/generator/random_decimal_spec.rb
@@ -0,0 +1,27 @@
+require 'pact/provider/generator/random_decimal'
+
+describe Pact::Provider::Generator::RandomDecimal do
+  generator = Pact::Provider::Generator::RandomDecimal.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'RandomDecimal' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'RandomDecimal' }
+    value = generator.call(hash)
+    expect(String(value).length).to eq 7
+  end
+
+  it 'call with digits' do
+    hash = { 'type' => 'RandomDecimal', 'digits' => 10 }
+    value = generator.call(hash)
+    expect(String(value).length).to eq 11
+  end
+end
diff --git a/spec/lib/pact/provider/generator/random_hexadecimal_spec.rb b/spec/lib/pact/provider/generator/random_hexadecimal_spec.rb
new file mode 100644
index 00000000..48bd6f94
--- /dev/null
+++ b/spec/lib/pact/provider/generator/random_hexadecimal_spec.rb
@@ -0,0 +1,25 @@
+require 'pact/provider/generator/random_hexadecimal'
+
+describe Pact::Provider::Generator::RandomHexadecimal do
+  generator = Pact::Provider::Generator::RandomHexadecimal.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'RandomHexadecimal' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'RandomHexadecimal' }
+    expect(generator.call(hash).length).to eq(8)
+  end
+
+  it 'call with size' do
+    hash = { 'type' => 'RandomHexadecimal', 'digits' => 2 }
+    expect(generator.call(hash).length).to eq(2)
+  end
+end
diff --git a/spec/lib/pact/provider/generator/random_int_spec.rb b/spec/lib/pact/provider/generator/random_int_spec.rb
new file mode 100644
index 00000000..e267c79b
--- /dev/null
+++ b/spec/lib/pact/provider/generator/random_int_spec.rb
@@ -0,0 +1,25 @@
+require 'pact/provider/generator/random_int'
+
+describe Pact::Provider::Generator::RandomInt do
+  generator = Pact::Provider::Generator::RandomInt.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'RandomInt' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'RandomInt' }
+    expect(generator.call(hash).instance_of?(Integer)).to be true
+  end
+
+  it 'call with min/max' do
+    hash = { 'type' => 'RandomInt', 'min' => 5, 'max' => 5 }
+    expect(generator.call(hash)).to eq 5
+  end
+end
diff --git a/spec/lib/pact/provider/generator/random_string_spec.rb b/spec/lib/pact/provider/generator/random_string_spec.rb
new file mode 100644
index 00000000..098563ec
--- /dev/null
+++ b/spec/lib/pact/provider/generator/random_string_spec.rb
@@ -0,0 +1,25 @@
+require 'pact/provider/generator/random_string'
+
+describe Pact::Provider::Generator::RandomString do
+  generator = Pact::Provider::Generator::RandomString.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'RandomString' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'RandomString' }
+    expect(generator.call(hash).length).to eq(20)
+  end
+
+  it 'call with size' do
+    hash = { 'type' => 'RandomString', 'size' => 30 }
+    expect(generator.call(hash).length).to eq(30)
+  end
+end
diff --git a/spec/lib/pact/provider/generator/regex_spec.rb b/spec/lib/pact/provider/generator/regex_spec.rb
new file mode 100644
index 00000000..db2738a1
--- /dev/null
+++ b/spec/lib/pact/provider/generator/regex_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/provider/generator/regex'
+
+describe Pact::Provider::Generator::Regex do
+  generator = Pact::Provider::Generator::Regex.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'Regex' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'Regex', 'pattern' => '(one|two)' }
+    expect(generator.call(hash)).to eq('one').or eq('two')
+  end
+end
diff --git a/spec/lib/pact/provider/generator/time_spec.rb b/spec/lib/pact/provider/generator/time_spec.rb
new file mode 100644
index 00000000..9baa6b9b
--- /dev/null
+++ b/spec/lib/pact/provider/generator/time_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/provider/generator/time'
+
+describe Pact::Provider::Generator::Time do
+  generator = Pact::Provider::Generator::Time.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'Time' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'Time' }
+    expect(generator.call(hash).length).to eq(5)
+  end
+end
diff --git a/spec/lib/pact/provider/generator/uuid_spec.rb b/spec/lib/pact/provider/generator/uuid_spec.rb
new file mode 100644
index 00000000..c19665bb
--- /dev/null
+++ b/spec/lib/pact/provider/generator/uuid_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/provider/generator/uuid'
+
+describe Pact::Provider::Generator::Uuid do
+  generator = Pact::Provider::Generator::Uuid.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'Uuid' }
+    expect(generator.can_generate?(hash)).to be true
+  end
+
+  it 'can_generate with a unsupported hash' do
+    hash = { 'type' => 'unknown' }
+    expect(generator.can_generate?(hash)).to be false
+  end
+
+  it 'call' do
+    hash = { 'type' => 'Uuid' }
+    expect(generator.call(hash).length).to eq(36)
+  end
+end
diff --git a/spec/lib/pact/provider/generators_spec.rb b/spec/lib/pact/provider/generators_spec.rb
new file mode 100644
index 00000000..198e1068
--- /dev/null
+++ b/spec/lib/pact/provider/generators_spec.rb
@@ -0,0 +1,124 @@
+require 'pact/provider/generators'
+require 'pact/provider/request'
+
+describe Pact::Provider::Generators do
+  it 'execute_generators with Boolean' do
+    hash = { 'type' => 'Boolean' }
+    expect(Pact::Provider::Generators.execute_generators(hash)).to eq(true).or eq(false)
+  end
+
+  it 'execute_generators with Date' do
+    hash = { 'type' => 'Date' }
+    expect(Pact::Provider::Generators.execute_generators(hash).length).to eq(10)
+  end
+
+  it 'execute_generators with DateTime' do
+    hash = { 'type' => 'DateTime' }
+    expect(Pact::Provider::Generators.execute_generators(hash).length).to eq(16)
+  end
+
+  it 'execute_generators with ProviderState' do
+    hash = { 'type' => 'ProviderState', 'expression' => 'Bearer ${access_token}' }
+    params = { 'access_token' => 'ABC' }
+    expect(Pact::Provider::Generators.execute_generators(hash, params)).to eq('Bearer ABC')
+  end
+
+  it 'execute_generators with RandomDecimal' do
+    hash = { 'type' => 'RandomDecimal' }
+    expect(String(Pact::Provider::Generators.execute_generators(hash)).length).to eq(7)
+  end
+
+  it 'execute_generators with RandomHexadecimal' do
+    hash = { 'type' => 'RandomHexadecimal' }
+    expect(Pact::Provider::Generators.execute_generators(hash).length).to eq(8)
+  end
+
+  it 'execute_generators with RandomInt' do
+    hash = { 'type' => 'RandomInt' }
+    expect(Pact::Provider::Generators.execute_generators(hash).instance_of?(Integer)).to be true
+  end
+
+  it 'execute_generators with RandomString' do
+    hash = { 'type' => 'RandomString' }
+    expect(Pact::Provider::Generators.execute_generators(hash).length).to eq(20)
+  end
+
+  it 'execute_generators with Regex' do
+    hash = { 'type' => 'Regex', 'pattern' => '(one|two)' }
+    expect(Pact::Provider::Generators.execute_generators(hash)).to eq('one').or eq('two')
+  end
+
+  it 'execute_generators with Time' do
+    hash = { 'type' => 'Time' }
+    expect(Pact::Provider::Generators.execute_generators(hash).length).to eq(5)
+  end
+
+  it 'execute_generators with Uuid' do
+    hash = { 'type' => 'Uuid' }
+    expect(Pact::Provider::Generators.execute_generators(hash).length).to eq(36)
+  end
+
+  it 'apply_generators for path' do
+    expected_request = Pact::Request::Expected.from_hash({
+      method: 'GET',
+      path: '/path/1',
+      generators: {
+        'path' => {
+          'type' => 'ProviderState',
+          'expression' => '/path/${itemID}'
+        }
+      }
+    })
+    state_params = {
+      'itemID' => 2
+    }
+    request = Pact::Provider::Request::Replayable.new(expected_request, state_params)
+    expect(request.path).to eq('/path/2')
+  end
+
+  it 'apply_generators for headers' do
+    expected_request = Pact::Request::Expected.from_hash({
+      method: 'GET',
+      path: '/path/1',
+      headers: {
+        'Authorization' => 'Bearer 123'
+      },
+      generators: {
+        'header' => {
+          '$.Authorization' => {
+            'expression' => 'Bearer ${accessToken}',
+            'type' => 'ProviderState'
+          }
+        }
+      }
+    })
+    state_params = {
+      'accessToken' => 'ABC'
+    }
+    request = Pact::Provider::Request::Replayable.new(expected_request, state_params)
+    expect(request.headers).to eq({
+      'HTTP_AUTHORIZATION' => 'Bearer ABC'
+    })
+  end
+
+  it 'apply_generators for body' do
+    expected_request = Pact::Request::Expected.from_hash({
+      method: 'GET',
+      path: '/path/1',
+      body: {
+        'result' => [
+          '12345F'
+        ]
+      },
+      generators: {
+        'body' => {
+          '$.result[0]' => {
+            'type' => 'RandomHexadecimal'
+          }
+        }
+      }
+    })
+    request = Pact::Provider::Request::Replayable.new(expected_request)
+    expect(request.body['result'][0].length).to eq(8)
+  end
+end