diff --git a/src/solanaceae/contact/contact_model4.hpp b/src/solanaceae/contact/contact_model4.hpp
index 35af3d2..7c85e48 100644
--- a/src/solanaceae/contact/contact_model4.hpp
+++ b/src/solanaceae/contact/contact_model4.hpp
@@ -27,5 +27,11 @@ struct ContactModel4I {
 	// delete
 	// triggers a destroy event on c
 	virtual bool leave(Contact4 c, std::string_view reason) = 0;
+
+	// invite c to to (as you speak it)
+	// eg on tox, only firends can be invited
+	virtual bool invite(Contact4 c, Contact4 to) = 0;
+	// might be called rapidly from ui code
+	virtual bool canInvite(Contact4 c, Contact4 to) = 0;
 };
 
diff --git a/src/solanaceae/contact/contact_store_i.hpp b/src/solanaceae/contact/contact_store_i.hpp
index d7f5119..e6bb13a 100644
--- a/src/solanaceae/contact/contact_store_i.hpp
+++ b/src/solanaceae/contact/contact_store_i.hpp
@@ -25,7 +25,7 @@ struct ContactStore4EventI {
 using ContactStore4EventProviderI = EventProviderI<ContactStore4EventI>;
 
 struct ContactStore4I : public ContactStore4EventProviderI{
-	static constexpr const char* version {"1"};
+	static constexpr const char* version {"2"};
 
 	virtual ContactRegistry4& registry(void) = 0;
 	virtual ContactHandle4 contactHandle(const Contact4 c) = 0;