diff --git a/lib/bindings/langs/flutter/breez_liquid_sdk/include/breez_liquid_sdk.h b/lib/bindings/langs/flutter/breez_liquid_sdk/include/breez_liquid_sdk.h
index e31e273..3a02e20 100644
--- a/lib/bindings/langs/flutter/breez_liquid_sdk/include/breez_liquid_sdk.h
+++ b/lib/bindings/langs/flutter/breez_liquid_sdk/include/breez_liquid_sdk.h
@@ -63,6 +63,7 @@ typedef struct wire_cst_payment {
   uint32_t timestamp;
   uint64_t amount_sat;
   uint64_t *fees_sat;
+  struct wire_cst_list_prim_u_8_strict *preimage;
   int32_t payment_type;
   int32_t status;
 } wire_cst_payment;
diff --git a/lib/bindings/src/breez_liquid_sdk.udl b/lib/bindings/src/breez_liquid_sdk.udl
index 4435a51..d4c2514 100644
--- a/lib/bindings/src/breez_liquid_sdk.udl
+++ b/lib/bindings/src/breez_liquid_sdk.udl
@@ -79,6 +79,7 @@ dictionary Payment {
     u32 timestamp;
     u64 amount_sat;
     u64? fees_sat = null;
+    string? preimage = null;
     PaymentType payment_type;
     PaymentState status;
 };
diff --git a/lib/core/src/frb/bridge.io.rs b/lib/core/src/frb/bridge.io.rs
index 7ee1844..e3b4c65 100644
--- a/lib/core/src/frb/bridge.io.rs
+++ b/lib/core/src/frb/bridge.io.rs
@@ -172,6 +172,7 @@ impl CstDecode<crate::model::Payment> for wire_cst_payment {
             timestamp: self.timestamp.cst_decode(),
             amount_sat: self.amount_sat.cst_decode(),
             fees_sat: self.fees_sat.cst_decode(),
+            preimage: self.preimage.cst_decode(),
             payment_type: self.payment_type.cst_decode(),
             status: self.status.cst_decode(),
         }
@@ -345,6 +346,7 @@ impl NewWithNullPtr for wire_cst_payment {
             timestamp: Default::default(),
             amount_sat: Default::default(),
             fees_sat: core::ptr::null_mut(),
+            preimage: core::ptr::null_mut(),
             payment_type: Default::default(),
             status: Default::default(),
         }
@@ -693,6 +695,7 @@ pub struct wire_cst_payment {
     timestamp: u32,
     amount_sat: u64,
     fees_sat: *mut u64,
+    preimage: *mut wire_cst_list_prim_u_8_strict,
     payment_type: i32,
     status: i32,
 }
diff --git a/lib/core/src/frb/bridge.rs b/lib/core/src/frb/bridge.rs
index 64b79ce..0cb384d 100644
--- a/lib/core/src/frb/bridge.rs
+++ b/lib/core/src/frb/bridge.rs
@@ -592,6 +592,7 @@ impl SseDecode for crate::model::Payment {
         let mut var_timestamp = <u32>::sse_decode(deserializer);
         let mut var_amountSat = <u64>::sse_decode(deserializer);
         let mut var_feesSat = <Option<u64>>::sse_decode(deserializer);
+        let mut var_preimage = <Option<String>>::sse_decode(deserializer);
         let mut var_paymentType = <crate::model::PaymentType>::sse_decode(deserializer);
         let mut var_status = <crate::model::PaymentState>::sse_decode(deserializer);
         return crate::model::Payment {
@@ -600,6 +601,7 @@ impl SseDecode for crate::model::Payment {
             timestamp: var_timestamp,
             amount_sat: var_amountSat,
             fees_sat: var_feesSat,
+            preimage: var_preimage,
             payment_type: var_paymentType,
             status: var_status,
         };
@@ -936,6 +938,7 @@ impl flutter_rust_bridge::IntoDart for crate::model::Payment {
             self.timestamp.into_into_dart().into_dart(),
             self.amount_sat.into_into_dart().into_dart(),
             self.fees_sat.into_into_dart().into_dart(),
+            self.preimage.into_into_dart().into_dart(),
             self.payment_type.into_into_dart().into_dart(),
             self.status.into_into_dart().into_dart(),
         ]
@@ -1289,6 +1292,7 @@ impl SseEncode for crate::model::Payment {
         <u32>::sse_encode(self.timestamp, serializer);
         <u64>::sse_encode(self.amount_sat, serializer);
         <Option<u64>>::sse_encode(self.fees_sat, serializer);
+        <Option<String>>::sse_encode(self.preimage, serializer);
         <crate::model::PaymentType>::sse_encode(self.payment_type, serializer);
         <crate::model::PaymentState>::sse_encode(self.status, serializer);
     }
diff --git a/lib/core/src/model.rs b/lib/core/src/model.rs
index b90a5cf..7749094 100644
--- a/lib/core/src/model.rs
+++ b/lib/core/src/model.rs
@@ -425,6 +425,8 @@ pub struct PaymentSwapData {
     /// Swap creation timestamp
     pub created_at: u32,
 
+    pub preimage: Option<String>,
+
     /// Amount sent by the swap payer
     pub payer_amount_sat: u64,
 
@@ -463,6 +465,9 @@ pub struct Payment {
     /// received.
     pub fees_sat: Option<u64>,
 
+    /// In case of a Send swap, this is the preimage of the paid invoice (proof of payment).
+    pub preimage: Option<String>,
+
     pub payment_type: PaymentType,
 
     /// Composite status representing the overall status of the payment.
@@ -485,6 +490,7 @@ impl Payment {
             fees_sat: swap
                 .as_ref()
                 .map(|s| s.payer_amount_sat - s.receiver_amount_sat),
+            preimage: swap.as_ref().and_then(|s| s.preimage.clone()),
             payment_type: tx.payment_type,
             status: match swap {
                 Some(swap) => swap.status,
diff --git a/lib/core/src/persist/migrations.rs b/lib/core/src/persist/migrations.rs
index 6548518..5e3ee22 100644
--- a/lib/core/src/persist/migrations.rs
+++ b/lib/core/src/persist/migrations.rs
@@ -13,15 +13,16 @@ pub(crate) fn current_migrations() -> Vec<&'static str> {
             state INTEGER NOT NULL
         ) STRICT;",
         "CREATE TABLE IF NOT EXISTS send_swaps (
-           id TEXT NOT NULL PRIMARY KEY,
-           invoice TEXT NOT NULL,
-           payer_amount_sat INTEGER NOT NULL,
-           receiver_amount_sat INTEGER NOT NULL,
-           create_response_json TEXT NOT NULL,
-           lockup_tx_id TEXT,
-           refund_tx_id TEXT,
-           created_at INTEGER NOT NULL,
-           state INTEGER NOT NULL
+            id TEXT NOT NULL PRIMARY KEY,
+            invoice TEXT NOT NULL,
+            preimage TEXT,
+            payer_amount_sat INTEGER NOT NULL,
+            receiver_amount_sat INTEGER NOT NULL,
+            create_response_json TEXT NOT NULL,
+            lockup_tx_id TEXT,
+            refund_tx_id TEXT,
+            created_at INTEGER NOT NULL,
+            state INTEGER NOT NULL
         ) STRICT;",
         "CREATE TABLE IF NOT EXISTS payment_tx_data (
             tx_id TEXT NOT NULL PRIMARY KEY,
diff --git a/lib/core/src/persist/mod.rs b/lib/core/src/persist/mod.rs
index abc451f..2980be7 100644
--- a/lib/core/src/persist/mod.rs
+++ b/lib/core/src/persist/mod.rs
@@ -112,6 +112,7 @@ impl Persister {
                 rs.state,
                 ss.id,
                 ss.created_at,
+                ss.preimage,
                 ss.payer_amount_sat,
                 ss.receiver_amount_sat,
                 ss.state
@@ -140,14 +141,16 @@ impl Persister {
                 let maybe_receive_swap_receiver_state: Option<PaymentState> = row.get(9)?;
                 let maybe_send_swap_id: Option<String> = row.get(10)?;
                 let maybe_send_swap_created_at: Option<u32> = row.get(11)?;
-                let maybe_send_swap_payer_amount_sat: Option<u64> = row.get(12)?;
-                let maybe_send_swap_receiver_amount_sat: Option<u64> = row.get(13)?;
-                let maybe_send_swap_state: Option<PaymentState> = row.get(14)?;
+                let maybe_send_swap_preimage: Option<String> = row.get(12)?;
+                let maybe_send_swap_payer_amount_sat: Option<u64> = row.get(13)?;
+                let maybe_send_swap_receiver_amount_sat: Option<u64> = row.get(14)?;
+                let maybe_send_swap_state: Option<PaymentState> = row.get(15)?;
 
                 let swap = match maybe_receive_swap_id {
                     Some(receive_swap_id) => Some(PaymentSwapData {
                         swap_id: receive_swap_id,
                         created_at: maybe_receive_swap_created_at.unwrap_or(utils::now()),
+                        preimage: None,
                         payer_amount_sat: maybe_receive_swap_payer_amount_sat.unwrap_or(0),
                         receiver_amount_sat: maybe_receive_swap_receiver_amount_sat.unwrap_or(0),
                         status: maybe_receive_swap_receiver_state.unwrap_or(PaymentState::Created),
@@ -155,6 +158,7 @@ impl Persister {
                     None => maybe_send_swap_id.map(|send_swap_id| PaymentSwapData {
                         swap_id: send_swap_id,
                         created_at: maybe_send_swap_created_at.unwrap_or(utils::now()),
+                        preimage: maybe_send_swap_preimage,
                         payer_amount_sat: maybe_send_swap_payer_amount_sat.unwrap_or(0),
                         receiver_amount_sat: maybe_send_swap_receiver_amount_sat.unwrap_or(0),
                         status: maybe_send_swap_state.unwrap_or(PaymentState::Created),
diff --git a/lib/core/src/persist/send.rs b/lib/core/src/persist/send.rs
index 9de3744..10f8c1a 100644
--- a/lib/core/src/persist/send.rs
+++ b/lib/core/src/persist/send.rs
@@ -160,13 +160,20 @@ impl Persister {
         con: &Connection,
         swap_id: &str,
         to_state: PaymentState,
+        preimage: Option<&str>,
         lockup_tx_id: Option<&str>,
         refund_tx_id: Option<&str>,
     ) -> Result<(), PaymentError> {
-        // Do not overwrite lockup_tx_id, refund_tx_id
+        // Do not overwrite preimage, lockup_tx_id, refund_tx_id
         con.execute(
             "UPDATE send_swaps
             SET
+                preimage =
+                    CASE
+                        WHEN preimage IS NULL THEN :preimage
+                        ELSE preimage
+                    END,
+
                 lockup_tx_id =
                     CASE
                         WHEN lockup_tx_id IS NULL THEN :lockup_tx_id
@@ -179,11 +186,12 @@ impl Persister {
                         ELSE refund_tx_id
                     END,
 
-                state=:state
+                state = :state
             WHERE
                 id = :id",
             named_params! {
                 ":id": swap_id,
+                ":preimage": preimage,
                 ":lockup_tx_id": lockup_tx_id,
                 ":refund_tx_id": refund_tx_id,
                 ":state": to_state,
diff --git a/lib/core/src/sdk.rs b/lib/core/src/sdk.rs
index df7d3ab..5e95cb0 100644
--- a/lib/core/src/sdk.rs
+++ b/lib/core/src/sdk.rs
@@ -192,6 +192,7 @@ impl LiquidSdk {
         &self,
         swap_id: &str,
         to_state: PaymentState,
+        preimage: Option<&str>,
         lockup_tx_id: Option<&str>,
         refund_tx_id: Option<&str>,
     ) -> Result<(), PaymentError> {
@@ -209,6 +210,7 @@ impl LiquidSdk {
             &con,
             swap_id,
             to_state,
+            preimage,
             lockup_tx_id,
             refund_tx_id,
         )
@@ -339,7 +341,7 @@ impl LiquidSdk {
                 let refund_tx_id =
                     self.try_refund(id, &swap_script, &keypair, receiver_amount_sat)?;
                 info!("Broadcast refund tx for Swap-in {id}. Tx id: {refund_tx_id}");
-                self.try_handle_send_swap_update(id, Pending, None, Some(&refund_tx_id))?;
+                self.try_handle_send_swap_update(id, Pending, None, None, Some(&refund_tx_id))?;
 
                 Ok(())
             }
@@ -587,7 +589,13 @@ impl LiquidSdk {
 
         Self::verify_payment_hash(&claim_tx_response.preimage, invoice)?;
         // After we confirm the preimage is correct, we mark this as complete
-        self.try_handle_send_swap_update(swap_id, Complete, None, None)?;
+        self.try_handle_send_swap_update(
+            swap_id,
+            Complete,
+            Some(&claim_tx_response.preimage),
+            None,
+            None,
+        )?;
 
         let (partial_sig, pub_nonce) =
             refund_tx.submarine_partial_sig(keypair, &claim_tx_response)?;
@@ -720,7 +728,13 @@ impl LiquidSdk {
                     };
 
                     lockup_tx_id = self.lockup_funds(swap_id, &create_response)?;
-                    self.try_handle_send_swap_update(swap_id, Pending, Some(&lockup_tx_id), None)?;
+                    self.try_handle_send_swap_update(
+                        swap_id,
+                        Pending,
+                        None,
+                        Some(&lockup_tx_id),
+                        None,
+                    )?;
                 }
 
                 // Boltz has detected the lockup in the mempool, we can speed up
@@ -962,7 +976,7 @@ impl LiquidSdk {
                     self.try_handle_receive_swap_update(&swap.id, Complete, None)?;
                 }
                 if let Some(swap) = pending_send_swaps_by_refund_tx_id.get(&tx_id) {
-                    self.try_handle_send_swap_update(&swap.id, Failed, None, None)?;
+                    self.try_handle_send_swap_update(&swap.id, Failed, None, None, None)?;
                 }
             }
 
diff --git a/packages/dart/lib/src/frb_generated.dart b/packages/dart/lib/src/frb_generated.dart
index 6e0428c..82416e5 100644
--- a/packages/dart/lib/src/frb_generated.dart
+++ b/packages/dart/lib/src/frb_generated.dart
@@ -517,15 +517,16 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
   Payment dco_decode_payment(dynamic raw) {
     // Codec=Dco (DartCObject based), see doc to use other codecs
     final arr = raw as List<dynamic>;
-    if (arr.length != 7) throw Exception('unexpected arr length: expect 7 but see ${arr.length}');
+    if (arr.length != 8) throw Exception('unexpected arr length: expect 8 but see ${arr.length}');
     return Payment(
       txId: dco_decode_String(arr[0]),
       swapId: dco_decode_opt_String(arr[1]),
       timestamp: dco_decode_u_32(arr[2]),
       amountSat: dco_decode_u_64(arr[3]),
       feesSat: dco_decode_opt_box_autoadd_u_64(arr[4]),
-      paymentType: dco_decode_payment_type(arr[5]),
-      status: dco_decode_payment_state(arr[6]),
+      preimage: dco_decode_opt_String(arr[5]),
+      paymentType: dco_decode_payment_type(arr[6]),
+      status: dco_decode_payment_state(arr[7]),
     );
   }
 
@@ -880,6 +881,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
     var var_timestamp = sse_decode_u_32(deserializer);
     var var_amountSat = sse_decode_u_64(deserializer);
     var var_feesSat = sse_decode_opt_box_autoadd_u_64(deserializer);
+    var var_preimage = sse_decode_opt_String(deserializer);
     var var_paymentType = sse_decode_payment_type(deserializer);
     var var_status = sse_decode_payment_state(deserializer);
     return Payment(
@@ -888,6 +890,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
         timestamp: var_timestamp,
         amountSat: var_amountSat,
         feesSat: var_feesSat,
+        preimage: var_preimage,
         paymentType: var_paymentType,
         status: var_status);
   }
@@ -1279,6 +1282,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
     sse_encode_u_32(self.timestamp, serializer);
     sse_encode_u_64(self.amountSat, serializer);
     sse_encode_opt_box_autoadd_u_64(self.feesSat, serializer);
+    sse_encode_opt_String(self.preimage, serializer);
     sse_encode_payment_type(self.paymentType, serializer);
     sse_encode_payment_state(self.status, serializer);
   }
diff --git a/packages/dart/lib/src/frb_generated.io.dart b/packages/dart/lib/src/frb_generated.io.dart
index 177e49f..3276572 100644
--- a/packages/dart/lib/src/frb_generated.io.dart
+++ b/packages/dart/lib/src/frb_generated.io.dart
@@ -454,6 +454,7 @@ abstract class RustLibApiImplPlatform extends BaseApiImpl<RustLibWire> {
     wireObj.timestamp = cst_encode_u_32(apiObj.timestamp);
     wireObj.amount_sat = cst_encode_u_64(apiObj.amountSat);
     wireObj.fees_sat = cst_encode_opt_box_autoadd_u_64(apiObj.feesSat);
+    wireObj.preimage = cst_encode_opt_String(apiObj.preimage);
     wireObj.payment_type = cst_encode_payment_type(apiObj.paymentType);
     wireObj.status = cst_encode_payment_state(apiObj.status);
   }
@@ -1156,6 +1157,8 @@ final class wire_cst_payment extends ffi.Struct {
 
   external ffi.Pointer<ffi.Uint64> fees_sat;
 
+  external ffi.Pointer<wire_cst_list_prim_u_8_strict> preimage;
+
   @ffi.Int32()
   external int payment_type;
 
diff --git a/packages/dart/lib/src/model.dart b/packages/dart/lib/src/model.dart
index 2fab78e..f5e9bb4 100644
--- a/packages/dart/lib/src/model.dart
+++ b/packages/dart/lib/src/model.dart
@@ -111,6 +111,9 @@ class Payment {
   /// sender. In other words, it's the delta between the amount that was sent and the amount
   /// received.
   final int? feesSat;
+
+  /// In case of a Send swap, this is the preimage of the paid invoice (proof of payment).
+  final String? preimage;
   final PaymentType paymentType;
 
   /// Composite status representing the overall status of the payment.
@@ -126,6 +129,7 @@ class Payment {
     required this.timestamp,
     required this.amountSat,
     this.feesSat,
+    this.preimage,
     required this.paymentType,
     required this.status,
   });
@@ -137,6 +141,7 @@ class Payment {
       timestamp.hashCode ^
       amountSat.hashCode ^
       feesSat.hashCode ^
+      preimage.hashCode ^
       paymentType.hashCode ^
       status.hashCode;
 
@@ -150,6 +155,7 @@ class Payment {
           timestamp == other.timestamp &&
           amountSat == other.amountSat &&
           feesSat == other.feesSat &&
+          preimage == other.preimage &&
           paymentType == other.paymentType &&
           status == other.status;
 }
diff --git a/packages/flutter/lib/flutter_breez_liquid_bindings_generated.dart b/packages/flutter/lib/flutter_breez_liquid_bindings_generated.dart
index beadefc..5e3139e 100644
--- a/packages/flutter/lib/flutter_breez_liquid_bindings_generated.dart
+++ b/packages/flutter/lib/flutter_breez_liquid_bindings_generated.dart
@@ -454,6 +454,8 @@ final class wire_cst_payment extends ffi.Struct {
 
   external ffi.Pointer<ffi.Uint64> fees_sat;
 
+  external ffi.Pointer<wire_cst_list_prim_u_8_strict> preimage;
+
   @ffi.Int32()
   external int payment_type;
 
diff --git a/packages/react-native/android/src/main/java/com/breezliquidsdk/BreezLiquidSDKMapper.kt b/packages/react-native/android/src/main/java/com/breezliquidsdk/BreezLiquidSDKMapper.kt
index 110203f..0144fb6 100644
--- a/packages/react-native/android/src/main/java/com/breezliquidsdk/BreezLiquidSDKMapper.kt
+++ b/packages/react-native/android/src/main/java/com/breezliquidsdk/BreezLiquidSDKMapper.kt
@@ -140,6 +140,7 @@ fun asPayment(payment: ReadableMap): Payment? {
     val timestamp = payment.getInt("timestamp").toUInt()
     val amountSat = payment.getDouble("amountSat").toULong()
     val feesSat = if (hasNonNullKey(payment, "feesSat")) payment.getDouble("feesSat").toULong() else null
+    val preimage = if (hasNonNullKey(payment, "preimage")) payment.getString("preimage") else null
     val paymentType = payment.getString("paymentType")?.let { asPaymentType(it) }!!
     val status = payment.getString("status")?.let { asPaymentState(it) }!!
     return Payment(
@@ -148,6 +149,7 @@ fun asPayment(payment: ReadableMap): Payment? {
         timestamp,
         amountSat,
         feesSat,
+        preimage,
         paymentType,
         status,
     )
@@ -160,6 +162,7 @@ fun readableMapOf(payment: Payment): ReadableMap {
         "timestamp" to payment.timestamp,
         "amountSat" to payment.amountSat,
         "feesSat" to payment.feesSat,
+        "preimage" to payment.preimage,
         "paymentType" to payment.paymentType.name.lowercase(),
         "status" to payment.status.name.lowercase(),
     )
diff --git a/packages/react-native/ios/BreezLiquidSDKMapper.swift b/packages/react-native/ios/BreezLiquidSDKMapper.swift
index 9e0e95a..ee6e8da 100644
--- a/packages/react-native/ios/BreezLiquidSDKMapper.swift
+++ b/packages/react-native/ios/BreezLiquidSDKMapper.swift
@@ -155,6 +155,13 @@ enum BreezLiquidSDKMapper {
             }
             feesSat = feesSatTmp
         }
+        var preimage: String?
+        if hasNonNilKey(data: payment, key: "preimage") {
+            guard let preimageTmp = payment["preimage"] as? String else {
+                throw LiquidSdkError.Generic(message: errUnexpectedValue(fieldName: "preimage"))
+            }
+            preimage = preimageTmp
+        }
         guard let paymentTypeTmp = payment["paymentType"] as? String else {
             throw LiquidSdkError.Generic(message: errMissingMandatoryField(fieldName: "paymentType", typeName: "Payment"))
         }
@@ -171,6 +178,7 @@ enum BreezLiquidSDKMapper {
             timestamp: timestamp,
             amountSat: amountSat,
             feesSat: feesSat,
+            preimage: preimage,
             paymentType: paymentType,
             status: status
         )
@@ -183,6 +191,7 @@ enum BreezLiquidSDKMapper {
             "timestamp": payment.timestamp,
             "amountSat": payment.amountSat,
             "feesSat": payment.feesSat == nil ? nil : payment.feesSat,
+            "preimage": payment.preimage == nil ? nil : payment.preimage,
             "paymentType": valueOf(paymentType: payment.paymentType),
             "status": valueOf(paymentState: payment.status),
         ]
diff --git a/packages/react-native/src/index.ts b/packages/react-native/src/index.ts
index 4af5072..fef89d4 100644
--- a/packages/react-native/src/index.ts
+++ b/packages/react-native/src/index.ts
@@ -40,6 +40,7 @@ export interface Payment {
     timestamp: number
     amountSat: number
     feesSat?: number
+    preimage?: string
     paymentType: PaymentType
     status: PaymentState
 }