diff --git a/bridges/bin/millau/runtime/src/lib.rs b/bridges/bin/millau/runtime/src/lib.rs
index 46921edd58..ff5b39439b 100644
--- a/bridges/bin/millau/runtime/src/lib.rs
+++ b/bridges/bin/millau/runtime/src/lib.rs
@@ -35,7 +35,6 @@ pub mod rialto_messages;
 use crate::rialto_messages::{ToRialtoMessagePayload, WithRialtoMessageBridge};
 
 use bridge_runtime_common::messages::{source::estimate_message_dispatch_and_delivery_fee, MessageBridge};
-use codec::Decode;
 use pallet_grandpa::{fg_primitives, AuthorityId as GrandpaId, AuthorityList as GrandpaAuthorityList};
 use pallet_transaction_payment::{FeeDetails, Multiplier, RuntimeDispatchInfo};
 use sp_api::impl_runtime_apis;
@@ -620,20 +619,11 @@ impl_runtime_apis! {
 			begin: bp_messages::MessageNonce,
 			end: bp_messages::MessageNonce,
 		) -> Vec<bp_messages::MessageDetails<Balance>> {
-			(begin..=end).filter_map(|nonce| {
-				let message_data = BridgeRialtoMessages::outbound_message_data(lane, nonce)?;
-				let decoded_payload = rialto_messages::ToRialtoMessagePayload::decode(
-					&mut &message_data.payload[..]
-				).ok()?;
-				Some(bp_messages::MessageDetails {
-					nonce,
-					dispatch_weight: decoded_payload.weight,
-					size: message_data.payload.len() as _,
-					delivery_and_dispatch_fee: message_data.fee,
-					dispatch_fee_payment: decoded_payload.dispatch_fee_payment,
-				})
-			})
-			.collect()
+			bridge_runtime_common::messages_api::outbound_message_details::<
+				Runtime,
+				WithRialtoMessagesInstance,
+				WithRialtoMessageBridge,
+			>(lane, begin, end)
 		}
 
 		fn latest_received_nonce(lane: bp_messages::LaneId) -> bp_messages::MessageNonce {
diff --git a/bridges/bin/rialto/runtime/src/lib.rs b/bridges/bin/rialto/runtime/src/lib.rs
index fe503154c8..762ef17102 100644
--- a/bridges/bin/rialto/runtime/src/lib.rs
+++ b/bridges/bin/rialto/runtime/src/lib.rs
@@ -41,7 +41,6 @@ pub mod rialto_poa;
 use crate::millau_messages::{ToMillauMessagePayload, WithMillauMessageBridge};
 
 use bridge_runtime_common::messages::{source::estimate_message_dispatch_and_delivery_fee, MessageBridge};
-use codec::Decode;
 use pallet_grandpa::{fg_primitives, AuthorityId as GrandpaId, AuthorityList as GrandpaAuthorityList};
 use pallet_transaction_payment::{FeeDetails, Multiplier, RuntimeDispatchInfo};
 use sp_api::impl_runtime_apis;
@@ -839,20 +838,11 @@ impl_runtime_apis! {
 			begin: bp_messages::MessageNonce,
 			end: bp_messages::MessageNonce,
 		) -> Vec<bp_messages::MessageDetails<Balance>> {
-			(begin..=end).filter_map(|nonce| {
-				let message_data = BridgeMillauMessages::outbound_message_data(lane, nonce)?;
-				let decoded_payload = millau_messages::ToMillauMessagePayload::decode(
-					&mut &message_data.payload[..]
-				).ok()?;
-				Some(bp_messages::MessageDetails {
-					nonce,
-					dispatch_weight: decoded_payload.weight,
-					size: message_data.payload.len() as _,
-					delivery_and_dispatch_fee: message_data.fee,
-					dispatch_fee_payment: decoded_payload.dispatch_fee_payment,
-				})
-			})
-			.collect()
+			bridge_runtime_common::messages_api::outbound_message_details::<
+				Runtime,
+				WithMillauMessagesInstance,
+				WithMillauMessageBridge,
+			>(lane, begin, end)
 		}
 
 		fn latest_received_nonce(lane: bp_messages::LaneId) -> bp_messages::MessageNonce {
diff --git a/bridges/bin/runtime-common/src/lib.rs b/bridges/bin/runtime-common/src/lib.rs
index ae7efb4a41..66f2c6c3a0 100644
--- a/bridges/bin/runtime-common/src/lib.rs
+++ b/bridges/bin/runtime-common/src/lib.rs
@@ -19,4 +19,5 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 pub mod messages;
+pub mod messages_api;
 pub mod messages_benchmarking;
diff --git a/bridges/bin/runtime-common/src/messages_api.rs b/bridges/bin/runtime-common/src/messages_api.rs
new file mode 100644
index 0000000000..d0f4180b5c
--- /dev/null
+++ b/bridges/bin/runtime-common/src/messages_api.rs
@@ -0,0 +1,52 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Helpers for implementing various message-related runtime API mthods.
+
+use crate::messages::{source::FromThisChainMessagePayload, MessageBridge};
+
+use bp_messages::{LaneId, MessageDetails, MessageNonce};
+use codec::Decode;
+use frame_support::traits::Instance;
+use sp_std::vec::Vec;
+
+/// Implementation of the `To*OutboundLaneApi::message_details`.
+pub fn outbound_message_details<Runtime, MessagesPalletInstance, BridgeConfig>(
+	lane: LaneId,
+	begin: MessageNonce,
+	end: MessageNonce,
+) -> Vec<MessageDetails<Runtime::OutboundMessageFee>>
+where
+	Runtime: pallet_bridge_messages::Config<MessagesPalletInstance>,
+	MessagesPalletInstance: Instance,
+	BridgeConfig: MessageBridge,
+{
+	(begin..=end)
+		.filter_map(|nonce| {
+			let message_data =
+				pallet_bridge_messages::Pallet::<Runtime, MessagesPalletInstance>::outbound_message_data(lane, nonce)?;
+			let decoded_payload =
+				FromThisChainMessagePayload::<BridgeConfig>::decode(&mut &message_data.payload[..]).ok()?;
+			Some(MessageDetails {
+				nonce,
+				dispatch_weight: decoded_payload.weight,
+				size: message_data.payload.len() as _,
+				delivery_and_dispatch_fee: message_data.fee,
+				dispatch_fee_payment: decoded_payload.dispatch_fee_payment,
+			})
+		})
+		.collect()
+}