diff --git a/plugins/commands/serve/mappers/command.rb b/plugins/commands/serve/mappers/command.rb
new file mode 100644
index 000000000..195475115
--- /dev/null
+++ b/plugins/commands/serve/mappers/command.rb
@@ -0,0 +1,22 @@
+module VagrantPlugins
+  module CommandServe
+    class Mappers
+      # Build a command arguments from a FuncSpec value
+      class CommandArgumentsFromSpec < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::FuncSpec::Value) { |arg|
+              arg.type == "hashicorp.vagrant.sdk.Command.Arguments" &&
+                !arg&.value&.value.nil?
+            }
+          end
+          super(inputs: inputs, output: SDK::Command::Arguments, func: method(:converter))
+        end
+
+        def converter(proto)
+          SDK::Command::Arguments.decode(proto.value.value)
+        end
+      end
+    end
+  end
+end
diff --git a/plugins/commands/serve/mappers/guest.rb b/plugins/commands/serve/mappers/guest.rb
new file mode 100644
index 000000000..02e38779c
--- /dev/null
+++ b/plugins/commands/serve/mappers/guest.rb
@@ -0,0 +1,53 @@
+module VagrantPlugins
+  module CommandServe
+    class Mappers
+      # Build a guest client from a FuncSpec value
+      class GuestFromSpec < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::FuncSpec::Value) { |arg|
+              arg.type == "hashicorp.vagrant.sdk.Args.Guest" &&
+                !arg&.value&.value.nil?
+            }
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Guest, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Guest.load(proto.value.value, broker: broker)
+        end
+      end
+
+      # Build a guest client from a proto instance
+      class GuestFromProto < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::Args::Guest)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Guest, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Guest.load(proto, broker: broker)
+        end
+      end
+
+      # Build a guest client from a serialized proto string
+      class GuestFromString < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: String)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Guest, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Guest.load(proto, broker: broker)
+        end
+      end
+    end
+  end
+end
diff --git a/plugins/commands/serve/mappers/machine.rb b/plugins/commands/serve/mappers/machine.rb
new file mode 100644
index 000000000..ecf03757b
--- /dev/null
+++ b/plugins/commands/serve/mappers/machine.rb
@@ -0,0 +1,53 @@
+module VagrantPlugins
+  module CommandServe
+    class Mappers
+      # Build a machine client from a FuncSpec value
+      class MachineFromSpec < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::FuncSpec::Value) { |arg|
+              arg.type == "hashicorp.vagrant.sdk.Args.Machine" &&
+                !arg&.value&.value.nil?
+            }
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Machine, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Machine.load(proto.value.value, broker: broker)
+        end
+      end
+
+      # Build a machine client from a proto instance
+      class MachineFromProto < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::Args::Target::Machine)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Machine, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Machine.load(proto, broker: broker)
+        end
+      end
+
+      # Build a machine client from a serialized proto string
+      class MachineFromString < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: String)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Machine, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Machine.load(proto, broker: broker)
+        end
+      end
+    end
+  end
+end
diff --git a/plugins/commands/serve/mappers/project.rb b/plugins/commands/serve/mappers/project.rb
new file mode 100644
index 000000000..375242ee1
--- /dev/null
+++ b/plugins/commands/serve/mappers/project.rb
@@ -0,0 +1,53 @@
+module VagrantPlugins
+  module CommandServe
+    class Mappers
+      # Build a project client from a FuncSpec value
+      class ProjectFromSpec < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::FuncSpec::Value) { |arg|
+              arg.type == "hashicorp.vagrant.sdk.Args.Project" &&
+                !arg&.value&.value.nil?
+            }
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Project, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Project.load(proto.value.value, broker: broker)
+        end
+      end
+
+      # Build a project client from a proto instance
+      class ProjectFromProto < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::Args::Project)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Project, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Project.load(proto, broker: broker)
+        end
+      end
+
+      # Build a machine client from a serialized proto string
+      class ProjectFromString < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: String)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Project, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Project.load(proto, broker: broker)
+        end
+      end
+    end
+  end
+end
diff --git a/plugins/commands/serve/mappers/target.rb b/plugins/commands/serve/mappers/target.rb
new file mode 100644
index 000000000..4db3dd5e0
--- /dev/null
+++ b/plugins/commands/serve/mappers/target.rb
@@ -0,0 +1,53 @@
+module VagrantPlugins
+  module CommandServe
+    class Mappers
+      # Build a target client from a FuncSpec value
+      class TargetFromSpec < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::FuncSpec::Value) { |arg|
+              arg.type == "hashicorp.vagrant.sdk.Args.Target" &&
+                !arg&.value&.value.nil?
+            }
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Target, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Target.load(proto.value.value, broker: broker)
+        end
+      end
+
+      # Build a target client from a proto instance
+      class TargetFromProto < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::Args::Target)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Target, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Target.load(proto, broker: broker)
+        end
+      end
+
+      # Build a target client from a serialized proto string
+      class TargetFromString < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: String)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Target, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Target.load(proto, broker: broker)
+        end
+      end
+    end
+  end
+end
diff --git a/plugins/commands/serve/mappers/target_index.rb b/plugins/commands/serve/mappers/target_index.rb
new file mode 100644
index 000000000..8a18017cf
--- /dev/null
+++ b/plugins/commands/serve/mappers/target_index.rb
@@ -0,0 +1,53 @@
+module VagrantPlugins
+  module CommandServe
+    class Mappers
+      # Build a target index client from a FuncSpec value
+      class TargetIndexFromSpec < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::FuncSpec::Value) { |arg|
+              arg.type == "hashicorp.vagrant.sdk.Args.TargetIndex" &&
+                !arg&.value&.value.nil?
+            }
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::TargetIndex, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::TargetIndex.load(proto.value.value, broker: broker)
+        end
+      end
+
+      # Build a target index client from a proto instance
+      class TargetIndexFromProto < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::Args::TargetIndex)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::TargetIndex, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::TargetIndex.load(proto, broker: broker)
+        end
+      end
+
+      # Build a target index client from a serialized proto string
+      class TargetIndexFromString < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: String)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::TargetIndex, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::TargetIndex.load(proto, broker: broker)
+        end
+      end
+    end
+  end
+end
diff --git a/plugins/commands/serve/mappers/terminal.rb b/plugins/commands/serve/mappers/terminal.rb
new file mode 100644
index 000000000..ac5da2a10
--- /dev/null
+++ b/plugins/commands/serve/mappers/terminal.rb
@@ -0,0 +1,53 @@
+module VagrantPlugins
+  module CommandServe
+    class Mappers
+      # Build a terminal client from a FuncSpec value
+      class TerminalFromSpec < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::FuncSpec::Value) { |arg|
+              arg.type == "hashicorp.vagrant.sdk.Args.TerminalUI" &&
+                !arg&.value&.value.nil?
+            }
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Terminal, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Terminal.load(proto.value.value, broker: broker)
+        end
+      end
+
+      # Build a terminal client from a proto instance
+      class TerminalFromProto < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: SDK::Args::TerminalUI)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Terminal, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Terminal.load(proto, broker: broker)
+        end
+      end
+
+      # Build a terminal client from a serialized proto string
+      class TerminalFromString < Mapper
+        def initialize
+          inputs = [].tap do |i|
+            i << Input.new(type: String)
+            i << Input.new(type: Broker)
+          end
+          super(inputs: inputs, output: Client::Terminal, func: method(:converter))
+        end
+
+        def converter(proto, broker)
+          Client::Terminal.load(proto, broker: broker)
+        end
+      end
+    end
+  end
+end