diff --git a/api/src/foreign.rs b/api/src/foreign.rs
index ead6d18..f17dcec 100644
--- a/api/src/foreign.rs
+++ b/api/src/foreign.rs
@@ -35,13 +35,12 @@ pub type ForeignCheckMiddleware =
 	fn(ForeignCheckMiddlewareFn, Option<NodeVersionInfo>, Option<&Slate>) -> Result<(), Error>;
 
 /// Middleware Identifiers for each function
+#[non_exhaustive]
 pub enum ForeignCheckMiddlewareFn {
 	/// check_version
 	CheckVersion,
 	/// build_coinbase
 	BuildCoinbase,
-	/// verify_slate_messages
-	VerifySlateMessages,
 	/// receive_tx
 	ReceiveTx,
 	/// contract_new
@@ -50,6 +49,8 @@ pub enum ForeignCheckMiddlewareFn {
 	ContractSign,
 	/// finalize_tx
 	FinalizeTx,
+	/// verify_payment_proof_invoice
+	VerifyPaymentProofInvoice,
 }
 
 /// Main interface into all wallet API functions.
@@ -457,6 +458,13 @@ where
 	pub fn finalize_tx(&self, slate: &Slate, post_automatically: bool) -> Result<Slate, Error> {
 		let mut w_lock = self.wallet_inst.lock();
 		let w = w_lock.lc_provider()?.wallet_inst()?;
+		if let Some(m) = self.middleware.as_ref() {
+			m(
+				ForeignCheckMiddlewareFn::FinalizeTx,
+				w.w2n_client().get_version_info(),
+				Some(slate),
+			)?;
+		}
 		let post_automatically = match self.doctest_mode {
 			true => false,
 			false => post_automatically,
@@ -506,6 +514,13 @@ where
 	) -> Result<(), Error> {
 		let mut w_lock = self.wallet_inst.lock();
 		let w = w_lock.lc_provider()?.wallet_inst()?;
+		if let Some(m) = self.middleware.as_ref() {
+			m(
+				ForeignCheckMiddlewareFn::VerifyPaymentProofInvoice,
+				w.w2n_client().get_version_info(),
+				None,
+			)?;
+		}
 		foreign::verify_payment_proof_invoice(w, recipient_address, proof)
 	}
 }
diff --git a/controller/tests/contract_early_proofs_srs.rs b/controller/tests/contract_early_proofs_srs.rs
index 5d61839..efac025 100644
--- a/controller/tests/contract_early_proofs_srs.rs
+++ b/controller/tests/contract_early_proofs_srs.rs
@@ -27,7 +27,7 @@ use grin_wallet_libwallet as libwallet;
 use impls::test_framework::{self};
 use libwallet::contract::my_fee_contribution;
 use libwallet::contract::types::{ContractNewArgsAPI, ContractSetupArgsAPI};
-use libwallet::{Slate, SlateState, Slatepacker, SlatepackerArgs, TxLogEntryType};
+use libwallet::{NodeVersionInfo, Slate, SlateState, Slatepacker, SlatepackerArgs, TxLogEntryType};
 use std::sync::atomic::Ordering;
 use std::thread;
 use std::time::Duration;
@@ -37,6 +37,21 @@ mod common;
 use common::{clean_output_dir, create_wallets, setup};
 use std::path::PathBuf;
 
+fn reject_proof_verification(
+	method: grin_wallet_api::ForeignCheckMiddlewareFn,
+	_node_version: Option<NodeVersionInfo>,
+	slate: Option<&Slate>,
+) -> Result<(), libwallet::Error> {
+	assert!(matches!(
+		method,
+		grin_wallet_api::ForeignCheckMiddlewareFn::VerifyPaymentProofInvoice
+	));
+	assert!(slate.is_none());
+	Err(libwallet::Error::GenericError(
+		"Proof rejected by middleware".to_string(),
+	))
+}
+
 fn roundtrip_slate(slate: &Slate, version: u16) -> Result<Slate, libwallet::Error> {
 	let packer = Slatepacker::new(SlatepackerArgs {
 		sender: None,
@@ -213,6 +228,23 @@ fn contract_early_proofs_srs_test_impl(test_dir: &'static str) -> Result<(), lib
 
 	// Should have all proof fields filled out
 	println!("INVOICE PROOF: {}", invoice_proof_json);
+	{
+		let api = grin_wallet_api::Foreign::new(
+			recv_wallet.clone(),
+			PathBuf::from(test_dir),
+			recv_mask.cloned(),
+			Some(reject_proof_verification),
+			false,
+		);
+		let err = api
+			.verify_payment_proof_invoice(recipient_address.as_ref().unwrap(), &invoice_proof)
+			.unwrap_err();
+		assert!(matches!(
+			err,
+			libwallet::Error::GenericError(ref msg)
+				if msg == "Proof rejected by middleware"
+		));
+	}
 
 	wallet::controller::foreign_single_use(
 		recv_wallet.clone(),
diff --git a/controller/tests/no_change.rs b/controller/tests/no_change.rs
index aa1a56e..41c46e9 100644
--- a/controller/tests/no_change.rs
+++ b/controller/tests/no_change.rs
@@ -22,7 +22,7 @@ use std::path::PathBuf;
 
 use grin_wallet_libwallet as libwallet;
 use impls::test_framework::{self, LocalWalletClient};
-use libwallet::{InitTxArgs, IssueInvoiceTxArgs, Slate};
+use libwallet::{InitTxArgs, IssueInvoiceTxArgs, NodeVersionInfo, Slate};
 use std::sync::atomic::Ordering;
 use std::thread;
 use std::time::Duration;
@@ -31,6 +31,21 @@ use std::time::Duration;
 mod common;
 use common::{clean_output_dir, create_wallet_proxy, setup};
 
+fn reject_finalize(
+	method: grin_wallet_api::ForeignCheckMiddlewareFn,
+	_node_version: Option<NodeVersionInfo>,
+	slate: Option<&Slate>,
+) -> Result<(), libwallet::Error> {
+	assert!(matches!(
+		method,
+		grin_wallet_api::ForeignCheckMiddlewareFn::FinalizeTx
+	));
+	assert!(slate.is_some());
+	Err(libwallet::Error::GenericError(
+		"Finalize rejected by middleware".to_string(),
+	))
+}
+
 fn no_change_test_impl(test_dir: &'static str) -> Result<(), libwallet::Error> {
 	let mut wallet_proxy = create_wallet_proxy(test_dir);
 	let chain = wallet_proxy.chain.clone();
@@ -182,6 +197,21 @@ fn no_change_test_impl(test_dir: &'static str) -> Result<(), libwallet::Error> {
 	)?;
 
 	// wallet 2 finalizes and posts
+	{
+		let api = grin_wallet_api::Foreign::new(
+			wallet2.clone(),
+			PathBuf::from(test_dir),
+			mask2_i.clone(),
+			Some(reject_finalize),
+			false,
+		);
+		let err = api.finalize_tx(&slate, false).unwrap_err();
+		assert!(matches!(
+			err,
+			libwallet::Error::GenericError(ref msg)
+				if msg == "Finalize rejected by middleware"
+		));
+	}
 	wallet::controller::foreign_single_use(
 		wallet2.clone(),
 		PathBuf::from(test_dir),