diff --git a/plugin.go b/plugin.go
new file mode 100644
index 0000000..2b4c89e
--- /dev/null
+++ b/plugin.go
@@ -0,0 +1,20 @@
+package pluginlib
+
+type PluginTerraformConfigProvider struct {
+	Vendor             string
+	Name               string
+	Version            string
+	ResourceName       string
+	Init               string `yaml:"init,omitempty"`
+	ProviderPerProject bool   `yaml:"provider_per_project,omitempty"` // todo
+	NameSuffix         string `yaml:"name_suffix,omitempty"`          // only used internally for upgrading Terraform providers
+}
+
+type PluginTerraformConfig struct {
+	Provider PluginTerraformConfigProvider
+}
+
+type PluginConfig struct {
+	Type      string
+	Terraform PluginTerraformConfig `yaml:"terraform,omitempty"`
+}
diff --git a/stackhead.go b/stackhead.go
index cce9795..19cbc54 100644
--- a/stackhead.go
+++ b/stackhead.go
@@ -1,7 +1,9 @@
 package pluginlib
 
-func StackHeadExecute(command string) error {
+import "bytes"
+
+func StackHeadExecute(command string) (bytes.Buffer, error) {
 	// mock function
 	// behaviour is implemented in StackHead main repository
-	return nil
+	return bytes.Buffer{}, nil
 }