diff --git a/README.md b/README.md
index a45d3dd..55be1b4 100644
--- a/README.md
+++ b/README.md
@@ -3,3 +3,69 @@
 ![Build status](https://github.com/pact-foundation/pact-support/workflows/Test/badge.svg)
 
 Provides shared code for the Pact gems
+
+## Compatibility
+
+<details><summary>Specification Compatibility</summary>
+
+| Version  | Stable | [Spec] Compatibility | 
+| -------  | ------ | -------------------- |
+| 1.x.x    | Yes    | 2, 3\*               |
+
+_\*_ v3 support is limited to the subset of functionality required to enable language inter-operable [Message support].
+
+- See V3 tracking [issue](https://github.com/pact-foundation/pact-ruby/issues/318).
+- See V4 tracking [issue](https://github.com/pact-foundation/pact-ruby/issues/319).
+
+Want V3/V4 support now? See the new standalone [pact-verifier](https://github.com/pact-foundation/pact-reference/tree/master/rust/pact_verifier_cli#standalone-pact-verifier)
+
+[message support]: https://github.com/pact-foundation/pact-specification/tree/version-3#introduces-messages-for-services-that-communicate-via-event-streams-and-message-queues
+
+</details>
+
+### Supported matching rules
+
+| matcher       | Spec Version | Implemented | Usage|
+|---------------|--------------|-------------|-------------|
+| Equality      | V1           |   |    |
+| Regex         | V2           | ✅  | `Pact.term(generate, matcher)` |
+| Type          | V2           | ✅  | `Pact.like(generate)` |
+| MinType       | V2           | ✅  | `Pact.each_like(generate, min: <val>)` |
+| MaxType       | V2           |   |    |
+| MinMaxType    | V2           |   |    |
+| Include       | V3           |   |    |
+| Integer       | V3           |   |    |
+| Decimal       | V3           |   |    |
+| Number        | V3           |   |    |
+| Timestamp     | V3           |   |    |
+| Time          | V3           |   |    |
+| Date          | V3           |   |    |
+| Null          | V3           |   |    |
+| Boolean       | V3           |   |    |
+| ContentType   | V3           |   |    |
+| Values        | V3           |   |    |
+| ArrayContains | V4           |   |    |
+| StatusCode    | V4           |   |    |
+| NotEmpty      | V4           |   |    |
+| Semver        | V4           |   |    |
+| EachKey       | V4           |   |    |
+| EachValue     | V4           |   |    |
+
+### Supported generators
+
+Currently limited to provider verification only. No current way to set in consumer tests.
+
+| Generator                | Spec Version | Implemented |
+|------------------------|--------------|----|
+| RandomInt              | V3           | ✅ |
+| RandomDecimal          | V3           | ✅ |
+| RandomHexadecimal      | V3           | ✅ |
+| RandomString           | V3           | ✅ |
+| Regex                  | V3           | ✅ |
+| Uuid                   | V3/V4        | ✅ |
+| Date                   | V3           | ✅ |
+| Time                   | V3           | ✅ |
+| DateTime               | V3           | ✅ |
+| RandomBoolean          | V3           | ✅ |
+| ProviderState          | V4           | ✅ |
+| MockServerURL          | V4           | 🚧 |
diff --git a/lib/pact/generator/date.rb b/lib/pact/generator/date.rb
new file mode 100644
index 0000000..d444241
--- /dev/null
+++ b/lib/pact/generator/date.rb
@@ -0,0 +1,62 @@
+require 'date'
+
+module Pact
+  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
diff --git a/lib/pact/generator/datetime.rb b/lib/pact/generator/datetime.rb
new file mode 100644
index 0000000..7a6fe1f
--- /dev/null
+++ b/lib/pact/generator/datetime.rb
@@ -0,0 +1,16 @@
+require 'date'
+
+module Pact
+  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
diff --git a/lib/pact/generator/provider_state.rb b/lib/pact/generator/provider_state.rb
new file mode 100644
index 0000000..aca84f7
--- /dev/null
+++ b/lib/pact/generator/provider_state.rb
@@ -0,0 +1,53 @@
+require 'pact/logging'
+
+module Pact
+  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]
+
+          logger.info "Could not subsitute provider state key #{variable}, have #{params}" unless params[variable]
+
+          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
diff --git a/lib/pact/generator/random_boolean.rb b/lib/pact/generator/random_boolean.rb
new file mode 100644
index 0000000..beb1224
--- /dev/null
+++ b/lib/pact/generator/random_boolean.rb
@@ -0,0 +1,14 @@
+module Pact
+  module Generator
+    # Boolean provides the boolean generator which will give a true or false value
+    class RandomBoolean
+      def can_generate?(hash)
+        hash.key?('type') && hash['type'] == 'RandomBoolean'
+      end
+
+      def call(_hash, _params = nil, _example_value = nil)
+        [true, false].sample
+      end
+    end
+  end
+end
diff --git a/lib/pact/generator/random_decimal.rb b/lib/pact/generator/random_decimal.rb
new file mode 100644
index 0000000..f255989
--- /dev/null
+++ b/lib/pact/generator/random_decimal.rb
@@ -0,0 +1,37 @@
+require 'bigdecimal'
+
+module Pact
+  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
diff --git a/lib/pact/generator/random_hexadecimal.rb b/lib/pact/generator/random_hexadecimal.rb
new file mode 100644
index 0000000..b90a3de
--- /dev/null
+++ b/lib/pact/generator/random_hexadecimal.rb
@@ -0,0 +1,19 @@
+require 'securerandom'
+
+module Pact
+  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
diff --git a/lib/pact/generator/random_int.rb b/lib/pact/generator/random_int.rb
new file mode 100644
index 0000000..fc157be
--- /dev/null
+++ b/lib/pact/generator/random_int.rb
@@ -0,0 +1,16 @@
+module Pact
+  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
diff --git a/lib/pact/generator/random_string.rb b/lib/pact/generator/random_string.rb
new file mode 100644
index 0000000..e61c57a
--- /dev/null
+++ b/lib/pact/generator/random_string.rb
@@ -0,0 +1,16 @@
+module Pact
+  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
diff --git a/lib/pact/generator/regex.rb b/lib/pact/generator/regex.rb
new file mode 100644
index 0000000..eb587b2
--- /dev/null
+++ b/lib/pact/generator/regex.rb
@@ -0,0 +1,17 @@
+require 'string_pattern'
+
+module Pact
+  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
diff --git a/lib/pact/generator/time.rb b/lib/pact/generator/time.rb
new file mode 100644
index 0000000..bbd7651
--- /dev/null
+++ b/lib/pact/generator/time.rb
@@ -0,0 +1,16 @@
+require 'date'
+
+module Pact
+  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
diff --git a/lib/pact/generator/uuid.rb b/lib/pact/generator/uuid.rb
new file mode 100644
index 0000000..457dcce
--- /dev/null
+++ b/lib/pact/generator/uuid.rb
@@ -0,0 +1,19 @@
+require 'securerandom'
+
+module Pact
+  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
diff --git a/lib/pact/generators.rb b/lib/pact/generators.rb
new file mode 100644
index 0000000..4d41b02
--- /dev/null
+++ b/lib/pact/generators.rb
@@ -0,0 +1,64 @@
+require 'pact/generator/random_boolean'
+require 'pact/generator/date'
+require 'pact/generator/datetime'
+require 'pact/generator/provider_state'
+require 'pact/generator/random_decimal'
+require 'pact/generator/random_hexadecimal'
+require 'pact/generator/random_int'
+require 'pact/generator/random_string'
+require 'pact/generator/regex'
+require 'pact/generator/time'
+require 'pact/generator/uuid'
+require 'pact/matching_rules/jsonpath'
+require 'pact/matching_rules/v3/extract'
+require 'jsonpath'
+
+module Pact
+    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::RandomBoolean.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
diff --git a/pact-support.gemspec b/pact-support.gemspec
index a984465..b240d6f 100644
--- a/pact-support.gemspec
+++ b/pact-support.gemspec
@@ -23,6 +23,8 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency "awesome_print", "~> 1.9"
   spec.add_runtime_dependency "diff-lcs", "~> 1.5"
   spec.add_runtime_dependency "expgen", "~> 0.1"
+  spec.add_runtime_dependency 'string_pattern', '~> 2.0'
+  spec.add_runtime_dependency 'jsonpath', '~> 1.0'
 
   spec.add_development_dependency "rspec", ">= 2.14", "< 4.0"
   spec.add_development_dependency "rake", "~> 13.0"
diff --git a/spec/lib/pact/generator/date_spec.rb b/spec/lib/pact/generator/date_spec.rb
new file mode 100644
index 0000000..4319d9e
--- /dev/null
+++ b/spec/lib/pact/generator/date_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/generator/date'
+
+describe Pact::Generator::Date do
+  generator = Pact::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/generator/datetime_spec.rb b/spec/lib/pact/generator/datetime_spec.rb
new file mode 100644
index 0000000..345a858
--- /dev/null
+++ b/spec/lib/pact/generator/datetime_spec.rb
@@ -0,0 +1,21 @@
+require 'pact/generator/datetime'
+
+describe Pact::Generator::DateTime do
+  generator = Pact::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/generator/provider_state_spec.rb b/spec/lib/pact/generator/provider_state_spec.rb
new file mode 100644
index 0000000..d371685
--- /dev/null
+++ b/spec/lib/pact/generator/provider_state_spec.rb
@@ -0,0 +1,37 @@
+require 'pact/generator/provider_state'
+
+describe Pact::Generator::ProviderState do
+  generator = Pact::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/generator/random_boolean_spec.rb b/spec/lib/pact/generator/random_boolean_spec.rb
new file mode 100644
index 0000000..8834861
--- /dev/null
+++ b/spec/lib/pact/generator/random_boolean_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/generator/random_boolean'
+
+describe Pact::Generator::RandomBoolean do
+  generator = Pact::Generator::RandomBoolean.new
+
+  it 'can_generate with a supported hash' do
+    hash = { 'type' => 'RandomBoolean' }
+    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' => 'RandomBoolean' }
+    expect(generator.call(hash)).to eq(true).or eq(false)
+  end
+end
diff --git a/spec/lib/pact/generator/random_decimal_spec.rb b/spec/lib/pact/generator/random_decimal_spec.rb
new file mode 100644
index 0000000..4c1689f
--- /dev/null
+++ b/spec/lib/pact/generator/random_decimal_spec.rb
@@ -0,0 +1,27 @@
+require 'pact/generator/random_decimal'
+
+describe Pact::Generator::RandomDecimal do
+  generator = Pact::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/generator/random_hexadecimal_spec.rb b/spec/lib/pact/generator/random_hexadecimal_spec.rb
new file mode 100644
index 0000000..8b124ba
--- /dev/null
+++ b/spec/lib/pact/generator/random_hexadecimal_spec.rb
@@ -0,0 +1,25 @@
+require 'pact/generator/random_hexadecimal'
+
+describe Pact::Generator::RandomHexadecimal do
+  generator = Pact::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/generator/random_int_spec.rb b/spec/lib/pact/generator/random_int_spec.rb
new file mode 100644
index 0000000..a2290fd
--- /dev/null
+++ b/spec/lib/pact/generator/random_int_spec.rb
@@ -0,0 +1,25 @@
+require 'pact/generator/random_int'
+
+describe Pact::Generator::RandomInt do
+  generator = Pact::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/generator/random_string_spec.rb b/spec/lib/pact/generator/random_string_spec.rb
new file mode 100644
index 0000000..8675058
--- /dev/null
+++ b/spec/lib/pact/generator/random_string_spec.rb
@@ -0,0 +1,25 @@
+require 'pact/generator/random_string'
+
+describe Pact::Generator::RandomString do
+  generator = Pact::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/generator/regex_spec.rb b/spec/lib/pact/generator/regex_spec.rb
new file mode 100644
index 0000000..723383d
--- /dev/null
+++ b/spec/lib/pact/generator/regex_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/generator/regex'
+
+describe Pact::Generator::Regex do
+  generator = Pact::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/generator/time_spec.rb b/spec/lib/pact/generator/time_spec.rb
new file mode 100644
index 0000000..21cd9a5
--- /dev/null
+++ b/spec/lib/pact/generator/time_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/generator/time'
+
+describe Pact::Generator::Time do
+  generator = Pact::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/generator/uuid_spec.rb b/spec/lib/pact/generator/uuid_spec.rb
new file mode 100644
index 0000000..aa9a94d
--- /dev/null
+++ b/spec/lib/pact/generator/uuid_spec.rb
@@ -0,0 +1,20 @@
+require 'pact/generator/uuid'
+
+describe Pact::Generator::Uuid do
+  generator = Pact::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/generators_spec.rb b/spec/lib/pact/generators_spec.rb
new file mode 100644
index 0000000..5a190a5
--- /dev/null
+++ b/spec/lib/pact/generators_spec.rb
@@ -0,0 +1,59 @@
+require 'pact/generators'
+
+describe Pact::Generators do
+  it 'execute_generators with RandomBoolean' do
+    hash = { 'type' => 'RandomBoolean' }
+    expect(Pact::Generators.execute_generators(hash)).to eq(true).or eq(false)
+  end
+
+  it 'execute_generators with Date' do
+    hash = { 'type' => 'Date' }
+    expect(Pact::Generators.execute_generators(hash).length).to eq(10)
+  end
+
+  it 'execute_generators with DateTime' do
+    hash = { 'type' => 'DateTime' }
+    expect(Pact::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::Generators.execute_generators(hash, params)).to eq('Bearer ABC')
+  end
+
+  it 'execute_generators with RandomDecimal' do
+    hash = { 'type' => 'RandomDecimal' }
+    expect(String(Pact::Generators.execute_generators(hash)).length).to eq(7)
+  end
+
+  it 'execute_generators with RandomHexadecimal' do
+    hash = { 'type' => 'RandomHexadecimal' }
+    expect(Pact::Generators.execute_generators(hash).length).to eq(8)
+  end
+
+  it 'execute_generators with RandomInt' do
+    hash = { 'type' => 'RandomInt' }
+    expect(Pact::Generators.execute_generators(hash).instance_of?(Integer)).to be true
+  end
+
+  it 'execute_generators with RandomString' do
+    hash = { 'type' => 'RandomString' }
+    expect(Pact::Generators.execute_generators(hash).length).to eq(20)
+  end
+
+  it 'execute_generators with Regex' do
+    hash = { 'type' => 'Regex', 'pattern' => '(one|two)' }
+    expect(Pact::Generators.execute_generators(hash)).to eq('one').or eq('two')
+  end
+
+  it 'execute_generators with Time' do
+    hash = { 'type' => 'Time' }
+    expect(Pact::Generators.execute_generators(hash).length).to eq(5)
+  end
+
+  it 'execute_generators with Uuid' do
+    hash = { 'type' => 'Uuid' }
+    expect(Pact::Generators.execute_generators(hash).length).to eq(36)
+  end
+end