diff --git a/core/build.gradle.kts b/core/build.gradle.kts
index d69fc65004..e58fbbd2fe 100644
--- a/core/build.gradle.kts
+++ b/core/build.gradle.kts
@@ -17,6 +17,7 @@ dependencies {
 
   implementation(libs.apache.commons.lang3)
   implementation(libs.bcastle)
+  implementation(libs.bcutil)
   implementation(libs.commons.beanutils)
   implementation(libs.commons.codec)
   implementation(libs.commons.io)
diff --git a/core/src/main/java/org/stellar/anchor/auth/Sep10Jwt.java b/core/src/main/java/org/stellar/anchor/auth/Sep10Jwt.java
index c990686c37..83b38d3e1d 100644
--- a/core/src/main/java/org/stellar/anchor/auth/Sep10Jwt.java
+++ b/core/src/main/java/org/stellar/anchor/auth/Sep10Jwt.java
@@ -9,9 +9,7 @@
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.Setter;
-import org.stellar.sdk.AccountConverter;
-import org.stellar.sdk.KeyPair;
-import org.stellar.sdk.xdr.MuxedAccount;
+import org.stellar.sdk.MuxedAccount;
 
 @Getter
 @Setter
@@ -111,13 +109,11 @@ void updateAccountAndMemo() {
         this.accountMemo = null;
 
         try {
-          MuxedAccount maybeMuxedAccount = AccountConverter.enableMuxed().encode(sub);
-          MuxedAccount.MuxedAccountMed25519 muxedAccount = maybeMuxedAccount.getMed25519();
-          if (muxedAccount != null) {
+          MuxedAccount maybeMuxedAccount = new MuxedAccount(sub);
+          if (maybeMuxedAccount.getMuxedId() != null) {
             this.muxedAccount = sub;
-            byte[] pubKeyBytes = muxedAccount.getEd25519().getUint256();
-            this.account = KeyPair.fromPublicKey(pubKeyBytes).getAccountId();
-            this.muxedAccountId = muxedAccount.getId().getUint64().getNumber().longValue();
+            this.account = maybeMuxedAccount.getAccountId();
+            this.muxedAccountId = maybeMuxedAccount.getMuxedId().longValue();
           }
         } catch (Exception ignored) {
         }
diff --git a/core/src/main/java/org/stellar/anchor/horizon/Horizon.java b/core/src/main/java/org/stellar/anchor/horizon/Horizon.java
index d9727f2005..d648264363 100644
--- a/core/src/main/java/org/stellar/anchor/horizon/Horizon.java
+++ b/core/src/main/java/org/stellar/anchor/horizon/Horizon.java
@@ -2,16 +2,18 @@
 
 import static org.stellar.anchor.api.asset.AssetInfo.NATIVE_ASSET_CODE;
 
-import java.io.IOException;
-import java.util.Arrays;
 import java.util.List;
 import lombok.Getter;
 import org.stellar.anchor.config.AppConfig;
 import org.stellar.anchor.util.AssetHelper;
 import org.stellar.sdk.AssetTypeCreditAlphaNum;
 import org.stellar.sdk.Server;
+import org.stellar.sdk.TrustLineAsset;
+import org.stellar.sdk.exception.NetworkException;
+import org.stellar.sdk.requests.PaymentsRequestBuilder;
 import org.stellar.sdk.responses.AccountResponse;
 import org.stellar.sdk.responses.operations.OperationResponse;
+import org.stellar.sdk.xdr.AssetType;
 
 /** The horizon-server. */
 public class Horizon {
@@ -30,7 +32,7 @@ public Server getServer() {
     return this.horizonServer;
   }
 
-  public boolean isTrustlineConfigured(String account, String asset) throws IOException {
+  public boolean isTrustlineConfigured(String account, String asset) throws NetworkException {
     String assetCode = AssetHelper.getAssetCode(asset);
     if (NATIVE_ASSET_CODE.equals(assetCode)) {
       return true;
@@ -38,13 +40,15 @@ public boolean isTrustlineConfigured(String account, String asset) throws IOExce
     String assetIssuer = AssetHelper.getAssetIssuer(asset);
 
     AccountResponse accountResponse = getServer().accounts().account(account);
-    return Arrays.stream(accountResponse.getBalances())
+    return accountResponse.getBalances().stream()
         .anyMatch(
             balance -> {
-              if (balance.getAssetType().equals("credit_alphanum4")
-                  || balance.getAssetType().equals("credit_alphanum12")) {
+              TrustLineAsset trustLineAsset = balance.getTrustLineAsset();
+              if (trustLineAsset.getAssetType() == AssetType.ASSET_TYPE_CREDIT_ALPHANUM4
+                  || trustLineAsset.getAssetType() == AssetType.ASSET_TYPE_CREDIT_ALPHANUM12) {
                 AssetTypeCreditAlphaNum creditAsset =
-                    (AssetTypeCreditAlphaNum) balance.getAsset().get();
+                    (AssetTypeCreditAlphaNum) trustLineAsset.getAsset();
+                assert creditAsset != null;
                 return creditAsset.getCode().equals(assetCode)
                     && creditAsset.getIssuer().equals(assetIssuer);
               }
@@ -52,7 +56,14 @@ public boolean isTrustlineConfigured(String account, String asset) throws IOExce
             });
   }
 
-  public List<OperationResponse> getStellarTxnOperations(String stellarTxnId) throws IOException {
+  /**
+   * Get payment operations for a transaction.
+   *
+   * @param stellarTxnId the transaction id
+   * @return the operations
+   * @throws NetworkException request failed, see {@link PaymentsRequestBuilder#execute()}
+   */
+  public List<OperationResponse> getStellarTxnOperations(String stellarTxnId) {
     return getServer()
         .payments()
         .includeTransactions(true)
diff --git a/core/src/main/java/org/stellar/anchor/sep10/Sep10Helper.java b/core/src/main/java/org/stellar/anchor/sep10/Sep10Helper.java
index e4eb73d494..62c792e255 100644
--- a/core/src/main/java/org/stellar/anchor/sep10/Sep10Helper.java
+++ b/core/src/main/java/org/stellar/anchor/sep10/Sep10Helper.java
@@ -10,7 +10,6 @@
 import org.stellar.anchor.api.exception.InvalidConfigException;
 import org.stellar.anchor.api.exception.SepException;
 import org.stellar.anchor.util.Sep1Helper;
-import org.stellar.sdk.FormatException;
 import org.stellar.sdk.KeyPair;
 
 public class Sep10Helper {
@@ -39,7 +38,7 @@ public static String fetchSigningKeyFromClientDomain(String clientDomain, boolea
       debugF("Validating client_domain signing key: {}", clientSigningKey);
       KeyPair.fromAccountId(clientSigningKey);
       return clientSigningKey;
-    } catch (IllegalArgumentException | FormatException e) {
+    } catch (IllegalArgumentException e) {
       infoF("SIGNING_KEY {} is not a valid Stellar account Id.", clientSigningKey);
       throw new SepException(
           String.format("SIGNING_KEY %s is not a valid Stellar account Id.", clientSigningKey));
diff --git a/core/src/main/java/org/stellar/anchor/sep10/Sep10Service.java b/core/src/main/java/org/stellar/anchor/sep10/Sep10Service.java
index 338e9da673..f8f1c8a4e7 100644
--- a/core/src/main/java/org/stellar/anchor/sep10/Sep10Service.java
+++ b/core/src/main/java/org/stellar/anchor/sep10/Sep10Service.java
@@ -11,7 +11,6 @@
 import io.jsonwebtoken.Jws;
 import io.micrometer.core.instrument.Counter;
 import io.micrometer.core.instrument.Metrics;
-import java.io.IOException;
 import java.time.Instant;
 import java.util.Arrays;
 import java.util.HashSet;
@@ -36,7 +35,10 @@
 import org.stellar.anchor.util.Log;
 import org.stellar.sdk.*;
 import org.stellar.sdk.Sep10Challenge.ChallengeTransaction;
-import org.stellar.sdk.requests.ErrorResponse;
+import org.stellar.sdk.exception.InvalidSep10ChallengeException;
+import org.stellar.sdk.exception.NetworkException;
+import org.stellar.sdk.operations.ManageDataOperation;
+import org.stellar.sdk.operations.Operation;
 import org.stellar.sdk.responses.AccountResponse;
 
 /** The Sep-10 protocol service. */
@@ -114,7 +116,7 @@ public ChallengeResponse createChallenge(
   }
 
   public ValidationResponse validateChallenge(ValidationRequest request)
-      throws IOException, InvalidSep10ChallengeException, SepValidationException {
+      throws SepValidationException {
     info("Validating SEP-10 challenge.");
 
     ChallengeTransaction challenge = parseChallenge(request);
@@ -176,8 +178,7 @@ public ChallengeResponse createChallengeResponse(
     }
   }
 
-  Transaction newChallenge(ChallengeRequest request, String clientSigningKey, Memo memo)
-      throws InvalidSep10ChallengeException {
+  Transaction newChallenge(ChallengeRequest request, String clientSigningKey, Memo memo) {
 
     KeyPair signer = KeyPair.fromSecretSeed(secretConfig.getSep10SigningSeed());
     long now = Instant.now().getEpochSecond();
@@ -380,7 +381,7 @@ void validateAccountFormat(ChallengeRequest request) throws SepException {
     // Validate account
     try {
       KeyPair.fromAccountId(request.getAccount());
-    } catch (Exception ex) {
+    } catch (IllegalArgumentException ex) {
       infoF("client wallet account ({}) is invalid", request.getAccount());
       throw new SepValidationException("Invalid account.");
     }
@@ -388,7 +389,7 @@ void validateAccountFormat(ChallengeRequest request) throws SepException {
 
   void validateChallengeRequest(
       ValidationRequest request, AccountResponse account, String clientDomain)
-      throws InvalidSep10ChallengeException, IOException, SepValidationException {
+      throws SepValidationException {
     // fetch the signers from the transaction
     Set<Sep10Challenge.Signer> signers = fetchSigners(account);
     // the signatures must be greater than the medium threshold of the account.
@@ -415,7 +416,7 @@ void validateChallengeRequest(
 
   Set<Sep10Challenge.Signer> fetchSigners(AccountResponse account) {
     // Find the signers of the client account.
-    return Arrays.stream(account.getSigners())
+    return account.getSigners().stream()
         .filter(as -> as.getType().equals("ed25519_public_key"))
         .map(as -> new Sep10Challenge.Signer(as.getKey(), as.getWeight()))
         .collect(Collectors.toSet());
@@ -423,7 +424,7 @@ Set<Sep10Challenge.Signer> fetchSigners(AccountResponse account) {
 
   AccountResponse fetchAccount(
       ValidationRequest request, ChallengeTransaction challenge, String clientDomain)
-      throws InvalidSep10ChallengeException, IOException, SepValidationException {
+      throws SepValidationException {
     // Check the client's account
     AccountResponse account;
     try {
@@ -432,7 +433,7 @@ AccountResponse fetchAccount(
       traceF("challenge account: {}", account);
       sep10ChallengeValidatedCounter.increment();
       return account;
-    } catch (ErrorResponse | IOException ex) {
+    } catch (NetworkException ex) {
       infoF("Account {} does not exist in the Stellar Network");
       // account not found
       // The client account does not exist, using the client's master key to verify.
@@ -494,8 +495,7 @@ String fetchClientDomain(ChallengeTransaction challenge) {
     return clientDomain;
   }
 
-  ChallengeTransaction parseChallenge(ValidationRequest request)
-      throws IOException, InvalidSep10ChallengeException, SepValidationException {
+  ChallengeTransaction parseChallenge(ValidationRequest request) throws SepValidationException {
 
     if (request == null || request.getTransaction() == null) {
       throw new SepValidationException("{transaction} is required.");
@@ -554,13 +554,17 @@ private String authUrl() {
    * @param network The network to connect to for verifying and retrieving.
    * @return The extracted home domain from the Manage Data operation within the SEP-10 challenge
    *     transaction.
-   * @throws IOException If read XDR string fails, the exception will be thrown.
    * @throws SepValidationException If the transaction is not a valid SEP-10 challenge transaction.
    */
   String extractHomeDomainFromChallengeXdr(String challengeXdr, Network network)
-      throws IOException, SepValidationException {
-    AbstractTransaction parsed =
-        Transaction.fromEnvelopeXdr(AccountConverter.enableMuxed(), challengeXdr, network);
+      throws SepValidationException {
+    AbstractTransaction parsed;
+    try {
+      parsed = Transaction.fromEnvelopeXdr(challengeXdr, network);
+    } catch (IllegalArgumentException e) {
+      throw new SepValidationException("Invalid challenge transaction.");
+    }
+
     if (!(parsed instanceof Transaction)) {
       throw new SepValidationException("Transaction cannot be a fee bump transaction");
     }
@@ -603,8 +607,7 @@ public synchronized Transaction newChallenge(
       TimeBounds timebounds,
       String clientDomain,
       String clientSigningKey,
-      Memo memo)
-      throws InvalidSep10ChallengeException {
+      Memo memo) {
     return Sep10Challenge.newChallenge(
         signer,
         network,
@@ -622,8 +625,7 @@ public synchronized ChallengeTransaction readChallengeTransaction(
       String serverAccountId,
       Network network,
       String domainName,
-      String webAuthDomain)
-      throws InvalidSep10ChallengeException, IOException {
+      String webAuthDomain) {
     return Sep10Challenge.readChallengeTransaction(
         challengeXdr, serverAccountId, network, domainName, webAuthDomain);
   }
@@ -634,8 +636,7 @@ public synchronized void verifyChallengeTransactionSigners(
       Network network,
       String domainName,
       String webAuthDomain,
-      Set<String> signers)
-      throws InvalidSep10ChallengeException, IOException {
+      Set<String> signers) {
     Sep10Challenge.verifyChallengeTransactionSigners(
         challengeXdr, serverAccountId, network, domainName, webAuthDomain, signers);
   }
@@ -647,8 +648,7 @@ public synchronized void verifyChallengeTransactionThreshold(
       String domainName,
       String webAuthDomain,
       int threshold,
-      Set<Sep10Challenge.Signer> signers)
-      throws InvalidSep10ChallengeException, IOException {
+      Set<Sep10Challenge.Signer> signers) {
     Sep10Challenge.verifyChallengeTransactionThreshold(
         challengeXdr, serverAccountId, network, domainName, webAuthDomain, threshold, signers);
   }
diff --git a/core/src/main/java/org/stellar/anchor/sep24/Sep24Service.java b/core/src/main/java/org/stellar/anchor/sep24/Sep24Service.java
index ba7d3d8268..ee91aefc66 100644
--- a/core/src/main/java/org/stellar/anchor/sep24/Sep24Service.java
+++ b/core/src/main/java/org/stellar/anchor/sep24/Sep24Service.java
@@ -188,7 +188,7 @@ public InteractiveTransactionResponse withdraw(
     try {
       debugF("checking if withdraw source account:{} is valid", sourceAccount);
       KeyPair.fromAccountId(sourceAccount);
-    } catch (Exception ex) {
+    } catch (IllegalArgumentException ex) {
       infoF("invalid account format: {}", sourceAccount);
       throw new SepValidationException(String.format("invalid account: %s", sourceAccount), ex);
     }
@@ -382,7 +382,7 @@ public InteractiveTransactionResponse deposit(Sep10Jwt token, Map<String, String
     try {
       debugF("checking if deposit destination account:{} is valid", destinationAccount);
       KeyPair.fromAccountId(destinationAccount);
-    } catch (Exception ex) {
+    } catch (IllegalArgumentException ex) {
       infoF("invalid account format: {}", destinationAccount);
       throw new SepValidationException(
           String.format("invalid account: %s", destinationAccount), ex);
diff --git a/core/src/main/java/org/stellar/anchor/sep6/RequestValidator.java b/core/src/main/java/org/stellar/anchor/sep6/RequestValidator.java
index 841d8565ca..49ba06bfbf 100644
--- a/core/src/main/java/org/stellar/anchor/sep6/RequestValidator.java
+++ b/core/src/main/java/org/stellar/anchor/sep6/RequestValidator.java
@@ -108,7 +108,7 @@ public void validateTypes(String requestType, String assetCode, List<String> val
   public void validateAccount(String account) throws AnchorException {
     try {
       KeyPair.fromAccountId(account);
-    } catch (RuntimeException ex) {
+    } catch (IllegalArgumentException ex) {
       throw new SepValidationException(String.format("invalid account %s", account));
     }
   }
diff --git a/core/src/main/java/org/stellar/anchor/util/AssetHelper.java b/core/src/main/java/org/stellar/anchor/util/AssetHelper.java
index 2aee8029d0..b61ec66ca4 100644
--- a/core/src/main/java/org/stellar/anchor/util/AssetHelper.java
+++ b/core/src/main/java/org/stellar/anchor/util/AssetHelper.java
@@ -37,7 +37,7 @@ public static boolean isNonNativeAsset(String assetCode, String assetIssuer) {
     try {
       KeyPair.fromAccountId(assetIssuer);
       return true;
-    } catch (Exception ex) {
+    } catch (IllegalArgumentException ex) {
       return false;
     }
   }
diff --git a/core/src/main/java/org/stellar/anchor/util/SepHelper.java b/core/src/main/java/org/stellar/anchor/util/SepHelper.java
index dc80d3e528..c181cbcfc1 100644
--- a/core/src/main/java/org/stellar/anchor/util/SepHelper.java
+++ b/core/src/main/java/org/stellar/anchor/util/SepHelper.java
@@ -11,9 +11,9 @@
 import org.stellar.anchor.api.exception.BadRequestException;
 import org.stellar.anchor.api.exception.InvalidStellarAccountException;
 import org.stellar.anchor.api.sep.SepTransactionStatus;
-import org.stellar.sdk.AccountConverter;
 import org.stellar.sdk.KeyPair;
-import org.stellar.sdk.xdr.*;
+import org.stellar.sdk.MuxedAccount;
+import org.stellar.sdk.xdr.MemoType;
 
 public class SepHelper {
   /**
@@ -59,15 +59,11 @@ public static String memoTypeString(MemoType memoType) {
   public static String getAccountMemo(String strAccount) throws InvalidStellarAccountException {
     String[] tokens = strAccount.split(":");
     switch (tokens.length) {
+        // TODO: Should we add a catch here to throw an InvalidStellarAccountException exception in
+        // case of invalid address?
       case 1:
-        AccountConverter accountConverter;
-        if (tokens[0].startsWith("G")) {
-          accountConverter = AccountConverter.disableMuxed();
-        } else {
-          accountConverter = AccountConverter.enableMuxed();
-        }
         // Check if the account is a valid G... or M...
-        accountConverter.encode(tokens[0]);
+        new MuxedAccount(tokens[0]);
         return null;
       case 2:
         KeyPair.fromAccountId(tokens[0]);
diff --git a/core/src/test/kotlin/org/stellar/anchor/horizon/HorizonTest.kt b/core/src/test/kotlin/org/stellar/anchor/horizon/HorizonTest.kt
index 56ac1c302c..f23648b48b 100644
--- a/core/src/test/kotlin/org/stellar/anchor/horizon/HorizonTest.kt
+++ b/core/src/test/kotlin/org/stellar/anchor/horizon/HorizonTest.kt
@@ -2,7 +2,6 @@ package org.stellar.anchor.horizon
 
 import io.mockk.every
 import io.mockk.mockk
-import java.util.*
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
 import kotlin.test.assertTrue
@@ -10,8 +9,10 @@ import org.junit.jupiter.api.Assertions.assertNotNull
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
 import org.stellar.anchor.config.AppConfig
+import org.stellar.sdk.Asset
 import org.stellar.sdk.AssetTypeCreditAlphaNum
 import org.stellar.sdk.Server
+import org.stellar.sdk.TrustLineAsset
 import org.stellar.sdk.requests.AccountsRequestBuilder
 import org.stellar.sdk.responses.AccountResponse
 import org.stellar.sdk.responses.AccountResponse.Balance
@@ -84,20 +85,21 @@ internal class HorizonTest {
     every { appConfig.stellarNetworkPassphrase } returns TEST_HORIZON_PASSPHRASE
     every { server.accounts() } returns accountsRequestBuilder
     every { accountsRequestBuilder.account(account) } returns accountResponse
-    every { balance1.getAssetType() } returns "credit_alphanum4"
-    every { balance1.getAsset() } returns Optional.of(asset1)
-    every { balance2.getAssetType() } returns "credit_alphanum12"
-    every { balance2.getAsset() } returns Optional.of(asset2)
-    every { asset1.getCode() } returns "USDC"
-    every { asset1.getIssuer() } returns "issuerAccount1"
-    every { asset2.getCode() } returns "USDC"
-    every { asset2.getIssuer() } returns "issuerAccount2"
-    every { accountResponse.getBalances() } returns arrayOf(balance1, balance2)
+
+    every { asset1.code } returns "USDC"
+    every { asset1.issuer } returns "issuerAccount1"
+    every { asset2.code } returns "USDC"
+    every { asset2.issuer } returns "issuerAccount2"
+
+    every { balance1.trustLineAsset } returns
+      TrustLineAsset(Asset.createNonNativeAsset(asset1.code, asset1.issuer))
+    every { balance2.trustLineAsset } returns
+      TrustLineAsset(Asset.createNonNativeAsset(asset2.code, asset2.issuer))
+    every { accountResponse.balances } returns listOf(balance1, balance2)
 
     val horizon = mockk<Horizon>()
     every { horizon.server } returns server
     every { horizon.isTrustlineConfigured(account, asset) } answers { callOriginal() }
-
     assertTrue(horizon.isTrustlineConfigured(account, asset))
   }
 
@@ -112,24 +114,25 @@ internal class HorizonTest {
     val balance1: Balance = mockk()
     val balance2: Balance = mockk()
     val balance3: Balance = mockk()
-    val asset1: AssetTypeCreditAlphaNum = mockk()
+    // val asset1: AssetTypeNative = mockk()
     val asset2: AssetTypeCreditAlphaNum = mockk()
     val asset3: AssetTypeCreditAlphaNum = mockk()
     every { server.accounts() } returns accountsRequestBuilder
     every { accountsRequestBuilder.account(account) } returns accountResponse
-    every { balance1.getAssetType() } returns "credit_alphanum8"
-    every { balance1.getAsset() } returns Optional.of(asset1)
-    every { balance2.getAssetType() } returns "credit_alphanum4"
-    every { balance2.getAsset() } returns Optional.of(asset2)
-    every { balance3.getAssetType() } returns "credit_alphanum4"
-    every { balance3.getAsset() } returns Optional.of(asset3)
-    every { asset1.getCode() } returns "USDC"
-    every { asset1.getIssuer() } returns "issuerAccount1"
-    every { asset2.getCode() } returns "SRT"
-    every { asset2.getIssuer() } returns "issuerAccount1"
-    every { asset3.getCode() } returns "USDC"
-    every { asset3.getIssuer() } returns "issuerAccount2"
-    every { accountResponse.getBalances() } returns arrayOf(balance1, balance2, balance3)
+
+    // asset 1 is native asset
+    every { asset2.code } returns "SRT"
+    every { asset2.issuer } returns "issuerAccount1"
+    every { asset3.code } returns "USDC"
+    every { asset3.issuer } returns "issuerAccount2"
+
+    every { balance1.trustLineAsset } returns TrustLineAsset(Asset.createNativeAsset())
+    every { balance2.trustLineAsset } returns
+      TrustLineAsset(Asset.createNonNativeAsset(asset2.code, asset2.issuer))
+    every { balance3.trustLineAsset } returns
+      TrustLineAsset(Asset.createNonNativeAsset(asset3.code, asset3.issuer))
+
+    every { accountResponse.balances } returns listOf(balance1, balance2, balance3)
 
     every { appConfig.horizonUrl } returns TEST_HORIZON_URI
     every { appConfig.stellarNetworkPassphrase } returns TEST_HORIZON_PASSPHRASE
@@ -137,7 +140,6 @@ internal class HorizonTest {
     val horizon = mockk<Horizon>()
     every { horizon.server } returns server
     every { horizon.isTrustlineConfigured(account, asset) } answers { callOriginal() }
-
     assertFalse(horizon.isTrustlineConfigured(account, asset))
   }
 }
diff --git a/core/src/test/kotlin/org/stellar/anchor/sep10/Sep10ServiceTest.kt b/core/src/test/kotlin/org/stellar/anchor/sep10/Sep10ServiceTest.kt
index b71afed85a..ebef7b94de 100644
--- a/core/src/test/kotlin/org/stellar/anchor/sep10/Sep10ServiceTest.kt
+++ b/core/src/test/kotlin/org/stellar/anchor/sep10/Sep10ServiceTest.kt
@@ -5,11 +5,8 @@ package org.stellar.anchor.sep10
 import com.google.common.io.BaseEncoding
 import com.google.gson.annotations.SerializedName
 import io.jsonwebtoken.Jwts
-import io.mockk.MockKAnnotations
-import io.mockk.every
+import io.mockk.*
 import io.mockk.impl.annotations.MockK
-import io.mockk.spyk
-import io.mockk.verify
 import java.io.IOException
 import java.security.SecureRandom
 import java.time.Instant
@@ -64,7 +61,10 @@ import org.stellar.anchor.util.GsonUtils
 import org.stellar.anchor.util.NetUtil
 import org.stellar.sdk.*
 import org.stellar.sdk.Network.*
-import org.stellar.sdk.requests.ErrorResponse
+import org.stellar.sdk.exception.BadRequestException
+import org.stellar.sdk.exception.InvalidSep10ChallengeException
+import org.stellar.sdk.operations.ManageDataOperation
+import org.stellar.sdk.operations.SetOptionsOperation
 import org.stellar.sdk.responses.AccountResponse
 import org.stellar.walletsdk.auth.DefaultAuthHeaderSigner
 import org.stellar.walletsdk.auth.createAuthSignToken
@@ -202,20 +202,26 @@ internal class Sep10ServiceTest {
 
     val sourceAccount = Account(serverKP.accountId, -1L)
     val op1DomainNameMandatory =
-      ManageDataOperation.Builder("$serverHomeDomain auth", encodedNonce)
-        .setSourceAccount(clientKP.accountId)
+      ManageDataOperation.builder()
+        .name("$serverHomeDomain auth")
+        .value(encodedNonce)
+        .sourceAccount(clientKP.accountId)
         .build()
     val op2WebAuthDomainMandatory =
-      ManageDataOperation.Builder("web_auth_domain", serverWebAuthDomain.toByteArray())
-        .setSourceAccount(serverKP.accountId)
+      ManageDataOperation.builder()
+        .name("web_auth_domain")
+        .value(serverWebAuthDomain.toByteArray())
+        .sourceAccount(serverKP.accountId)
         .build()
     val op3clientDomainOptional =
-      ManageDataOperation.Builder("client_domain", "lobstr.co".toByteArray())
-        .setSourceAccount(clientDomainKP.accountId)
+      ManageDataOperation.builder()
+        .name("client_domain")
+        .value("lobstr.co".toByteArray())
+        .sourceAccount(clientDomainKP.accountId)
         .build()
 
     val transaction =
-      TransactionBuilder(AccountConverter.enableMuxed(), sourceAccount, TESTNET)
+      TransactionBuilder(sourceAccount, TESTNET)
         .addPreconditions(
           TransactionPreconditions.builder().timeBounds(TimeBounds.expiresAfter(900)).build()
         )
@@ -279,20 +285,26 @@ internal class Sep10ServiceTest {
 
     val sourceAccount = Account(serverKP.accountId, -1L)
     val op1DomainNameMandatory =
-      ManageDataOperation.Builder("$serverHomeDomain auth", encodedNonce)
-        .setSourceAccount(clientKP.accountId)
+      ManageDataOperation.builder()
+        .name("$serverHomeDomain auth")
+        .value(encodedNonce)
+        .sourceAccount(clientKP.accountId)
         .build()
     val op2WebAuthDomainMandatory =
-      ManageDataOperation.Builder("web_auth_domain", serverWebAuthDomain.toByteArray())
-        .setSourceAccount(serverKP.accountId)
+      ManageDataOperation.builder()
+        .name("web_auth_domain")
+        .value(serverWebAuthDomain.toByteArray())
+        .sourceAccount(serverKP.accountId)
         .build()
     val op3clientDomainOptional =
-      ManageDataOperation.Builder("client_domain", "lobstr.co".toByteArray())
-        .setSourceAccount(clientDomainKP.accountId)
+      ManageDataOperation.builder()
+        .name("client_domain")
+        .value("lobstr.co".toByteArray())
+        .sourceAccount(clientDomainKP.accountId)
         .build()
 
     val transaction =
-      TransactionBuilder(AccountConverter.enableMuxed(), sourceAccount, TESTNET)
+      TransactionBuilder(sourceAccount, TESTNET)
         .addPreconditions(
           TransactionPreconditions.builder().timeBounds(TimeBounds.expiresAfter(900)).build()
         )
@@ -360,12 +372,16 @@ internal class Sep10ServiceTest {
     val vr = ValidationRequest()
     vr.transaction = createTestChallenge("", TEST_HOME_DOMAIN, false)
 
-    val accountResponse = spyk(AccountResponse(clientKeyPair.accountId, 1))
-    val signers =
-      arrayOf(TestSigner(clientKeyPair.accountId, "ed25519_public_key", 1, "").toSigner())
+    val mockSigners =
+      listOf(TestSigner(clientKeyPair.accountId, "ed25519_public_key", 1, "").toSigner())
+    val accountResponse =
+      mockk<AccountResponse> {
+        every { accountId } returns clientKeyPair.accountId
+        every { sequenceNumber } returns 1
+        every { signers } returns mockSigners
+        every { thresholds.medThreshold } returns 1
+      }
 
-    every { accountResponse.signers } returns signers
-    every { accountResponse.thresholds.medThreshold } returns 1
     every { horizon.server.accounts().account(ofType(String::class)) } returns accountResponse
 
     val response = sep10Service.validateChallenge(vr)
@@ -376,15 +392,20 @@ internal class Sep10ServiceTest {
   @Test
   @LockAndMockStatic([Sep10Challenge::class])
   fun `test validate challenge with client domain`() {
-    val accountResponse = spyk(AccountResponse(clientKeyPair.accountId, 1))
-    val signers =
-      arrayOf(
+    val mockSigners =
+      listOf(
         TestSigner(clientKeyPair.accountId, "ed25519_public_key", 1, "").toSigner(),
         TestSigner(clientDomainKeyPair.accountId, "ed25519_public_key", 1, "").toSigner()
       )
 
-    every { accountResponse.signers } returns signers
-    every { accountResponse.thresholds.medThreshold } returns 1
+    val accountResponse =
+      mockk<AccountResponse> {
+        every { accountId } returns clientKeyPair.accountId
+        every { sequenceNumber } returns 1
+        every { signers } returns mockSigners
+        every { thresholds.medThreshold } returns 1
+      }
+
     every { horizon.server.accounts().account(ofType(String::class)) } returns accountResponse
 
     val vr = ValidationRequest()
@@ -404,7 +425,7 @@ internal class Sep10ServiceTest {
     // exists
     every { horizon.server.accounts().account(ofType(String::class)) } answers
       {
-        throw ErrorResponse(0, "mock error")
+        throw BadRequestException(400, "mock error", null, null)
       }
     vr.transaction = createTestChallenge(TEST_CLIENT_DOMAIN, TEST_HOME_DOMAIN, false)
 
@@ -418,7 +439,7 @@ internal class Sep10ServiceTest {
 
     every { horizon.server.accounts().account(ofType(String::class)) } answers
       {
-        throw ErrorResponse(0, "mock error")
+        throw BadRequestException(400, "mock error", null, null)
       }
 
     sep10Service.validateChallenge(vr)
@@ -709,20 +730,26 @@ internal class Sep10ServiceTest {
 
     val sourceAccount = Account(serverKP.accountId, -1L)
     val op1DomainNameMandatory =
-      ManageDataOperation.Builder("$serverHomeDomain auth", encodedNonce)
-        .setSourceAccount(clientAddress)
+      ManageDataOperation.builder()
+        .name("$serverHomeDomain auth")
+        .value(encodedNonce)
+        .sourceAccount(clientAddress)
         .build()
     val op2WebAuthDomainMandatory =
-      ManageDataOperation.Builder("web_auth_domain", serverWebAuthDomain.toByteArray())
-        .setSourceAccount(serverKP.accountId)
+      ManageDataOperation.builder()
+        .name("web_auth_domain")
+        .value(serverWebAuthDomain.toByteArray())
+        .sourceAccount(serverKP.accountId)
         .build()
     val op3clientDomainOptional =
-      ManageDataOperation.Builder("client_domain", "lobstr.co".toByteArray())
-        .setSourceAccount(clientDomainKP.accountId)
+      ManageDataOperation.builder()
+        .name("client_domain")
+        .value("lobstr.co".toByteArray())
+        .sourceAccount(clientDomainKP.accountId)
         .build()
 
     val transaction =
-      TransactionBuilder(AccountConverter.enableMuxed(), sourceAccount, network)
+      TransactionBuilder(sourceAccount, network)
         .addPreconditions(
           TransactionPreconditions.builder().timeBounds(TimeBounds.expiresAfter(900)).build()
         )
@@ -757,18 +784,19 @@ internal class Sep10ServiceTest {
 
     val clientAccount = horizon.server.accounts().account(clientMasterKP.accountId)
     val multisigTx =
-      TransactionBuilder(AccountConverter.enableMuxed(), clientAccount, network)
+      TransactionBuilder(clientAccount, network)
         .addPreconditions(
           TransactionPreconditions.builder().timeBounds(TimeBounds.expiresAfter(900)).build()
         )
         .setBaseFee(300)
         .addOperation(
-          SetOptionsOperation.Builder()
-            .setLowThreshold(20)
-            .setMediumThreshold(20)
-            .setHighThreshold(20)
-            .setSigner(Signer.ed25519PublicKey(clientSecondaryKP), 10)
-            .setMasterKeyWeight(10)
+          SetOptionsOperation.builder()
+            .lowThreshold(20)
+            .mediumThreshold(20)
+            .highThreshold(20)
+            .signer(Signer.ed25519PublicKey(clientSecondaryKP))
+            .signerWeight(10)
+            .masterKeyWeight(10)
             .build()
         )
         .build()
diff --git a/essential-tests/src/testFixtures/kotlin/org/stellar/anchor/platform/AbstractIntegrationTests.kt b/essential-tests/src/testFixtures/kotlin/org/stellar/anchor/platform/AbstractIntegrationTests.kt
index ca70c81646..1e8e4bc2ea 100644
--- a/essential-tests/src/testFixtures/kotlin/org/stellar/anchor/platform/AbstractIntegrationTests.kt
+++ b/essential-tests/src/testFixtures/kotlin/org/stellar/anchor/platform/AbstractIntegrationTests.kt
@@ -69,7 +69,7 @@ abstract class AbstractIntegrationTests(val config: TestConfig) {
           .records
       for (payment in payments) {
         if (payment is PaymentOperationResponse) {
-          if (payment.transaction.get().memo.toString() == TEST_PAYMENT_MEMO) {
+          if (payment.transaction.memo.toString() == TEST_PAYMENT_MEMO) {
             println("Found test payment")
             // initialize the test payment value pairs for injection
             testPaymentValues =
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index ac2a0accd2..eb6ea6644e 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -5,7 +5,8 @@ assertj = "3.26.0"
 aws-iam-auth = "2.1.1"
 aws-rds = "1.12.759"
 aws-sqs = "1.12.757"
-bcastle = "1.77"
+bcastle = "1.79"
+bcutil = "1.79"
 commons-beanutils = "1.9.4"
 commons-cli = "1.8.0"
 commons-codec = "1.17.0"
@@ -27,7 +28,7 @@ jakarta-annotation-api = "3.0.0"
 jakarta-transaction-api = "2.0.1"
 jakarta-validation-api = "3.1.0"
 jakarta-xml-bind-api = "4.0.2"
-java-stellar-sdk = "0.44.1"
+java-stellar-sdk = "1.0.0"
 jjwt = "0.12.5"
 jsonassert = "1.5.0"
 junit = "5.10.3"
@@ -52,7 +53,7 @@ spotbugs-annotations = "4.8.6"
 spring-context = "6.1.11"
 spring-kafka = "3.2.1"
 spring-retry = "2.0.6"
-stellar-wallet-sdk = "1.7.1"
+stellar-wallet-sdk = "2.0.0"
 
 # Plugin versions
 spotless = "6.25.0"
@@ -67,6 +68,7 @@ aws-iam-auth = { module = "software.amazon.msk:aws-msk-iam-auth", version.ref =
 aws-rds = { module = "com.amazonaws:aws-java-sdk-rds", version.ref = "aws-rds" }
 aws-sqs = { module = "com.amazonaws:aws-java-sdk-sqs", version.ref = "aws-sqs" }
 bcastle = { module = "org.bouncycastle:bcprov-jdk18on", version.ref = "bcastle" }
+bcutil = { module = "org.bouncycastle:bcutil-jdk18on", version.ref = "bcutil" }
 commons-beanutils = { module = "commons-beanutils:commons-beanutils", version.ref = "commons-beanutils" }
 commons-cli = { module = "commons-cli:commons-cli", version.ref = "commons-cli" }
 commons-codec = { module = "commons-codec:commons-codec", version.ref = "commons-codec" }
@@ -90,7 +92,7 @@ jakarta-annotation-api = { module = "jakarta.annotation:jakarta.annotation-api",
 jakarta-transaction-api = { module = "jakarta.transaction:jakarta.transaction-api", version.ref = "jakarta-transaction-api" }
 jakarta-validation-api = { module = "jakarta.validation:jakarta.validation-api", version.ref = "jakarta-validation-api" }
 jakarta-xml-bind-api = { module = "jakarta.xml.bind:jakarta.xml.bind-api", version.ref = "jakarta-xml-bind-api" }
-java-stellar-sdk = { module = "com.github.stellar:java-stellar-sdk", version.ref = "java-stellar-sdk" }
+java-stellar-sdk = { module = "network.lightsail:stellar-sdk", version.ref = "java-stellar-sdk" }
 jjwt = { module = "io.jsonwebtoken:jjwt", version.ref = "jjwt" }
 jsonassert = { module = "org.skyscreamer:jsonassert", version.ref = "jsonassert" }
 junit-api = { module = "org.junit.jupiter:junit-jupiter-api", version.ref = "junit" }
diff --git a/kotlin-reference-server/src/main/kotlin/org/stellar/reference/event/processor/Sep6EventProcessor.kt b/kotlin-reference-server/src/main/kotlin/org/stellar/reference/event/processor/Sep6EventProcessor.kt
index adbe0fd7b9..864c36a7aa 100644
--- a/kotlin-reference-server/src/main/kotlin/org/stellar/reference/event/processor/Sep6EventProcessor.kt
+++ b/kotlin-reference-server/src/main/kotlin/org/stellar/reference/event/processor/Sep6EventProcessor.kt
@@ -1,5 +1,6 @@
 package org.stellar.reference.event.processor
 
+import java.math.BigDecimal
 import java.time.Instant
 import java.util.*
 import kotlinx.coroutines.runBlocking
@@ -17,6 +18,9 @@ import org.stellar.reference.log
 import org.stellar.reference.service.SepHelper
 import org.stellar.reference.transactionWithRetry
 import org.stellar.sdk.*
+import org.stellar.sdk.exception.BadRequestException
+import org.stellar.sdk.operations.PaymentOperation
+import org.stellar.sdk.responses.TransactionResponse
 
 class Sep6EventProcessor(
   private val config: Config,
@@ -438,14 +442,22 @@ class Sep6EventProcessor(
         .addPreconditions(
           TransactionPreconditions.builder().timeBounds(TimeBounds.expiresAfter(60)).build()
         )
-        .addOperation(PaymentOperation.Builder(destination, asset, amount).build())
+        .addOperation(
+          PaymentOperation.builder()
+            .destination(destination)
+            .asset(asset)
+            .amount(BigDecimal(amount))
+            .build()
+        )
         .build()
     transaction.sign(KeyPair.fromSecretSeed(config.appSettings.secret))
-    val txnResponse = server.submitTransaction(transaction)
-    if (!txnResponse.isSuccess) {
-      throw RuntimeException("Error submitting transaction: ${txnResponse.extras.resultCodes}")
+    val txnResponse: TransactionResponse
+    try {
+      txnResponse = server.submitTransaction(transaction)
+    } catch (e: BadRequestException) {
+      throw RuntimeException("Error submitting transaction: ${e.problem?.extras?.resultCodes}")
     }
-
+    assert(txnResponse.successful)
     return txnResponse.hash
   }
 
diff --git a/kotlin-reference-server/src/main/kotlin/org/stellar/reference/service/SepHelper.kt b/kotlin-reference-server/src/main/kotlin/org/stellar/reference/service/SepHelper.kt
index 6dae87760e..0f26f6622e 100644
--- a/kotlin-reference-server/src/main/kotlin/org/stellar/reference/service/SepHelper.kt
+++ b/kotlin-reference-server/src/main/kotlin/org/stellar/reference/service/SepHelper.kt
@@ -20,6 +20,9 @@ import org.stellar.anchor.util.GsonUtils
 import org.stellar.reference.data.*
 import org.stellar.reference.data.Transaction
 import org.stellar.sdk.*
+import org.stellar.sdk.exception.BadRequestException
+import org.stellar.sdk.operations.PaymentOperation
+import org.stellar.sdk.responses.TransactionResponse
 
 class SepHelper(private val cfg: Config) {
   private val log = KotlinLogging.logger {}
@@ -97,7 +100,11 @@ class SepHelper(private val cfg: Config) {
           TransactionPreconditions.builder().timeBounds(TimeBounds.expiresAfter(60)).build()
         )
         .addOperation(
-          PaymentOperation.Builder(destinationAddress, asset, amount.toPlainString()).build()
+          PaymentOperation.builder()
+            .destination(destinationAddress)
+            .asset(asset)
+            .amount(amount)
+            .build()
         )
 
     if (memo != null && memoType != null) {
@@ -115,14 +122,15 @@ class SepHelper(private val cfg: Config) {
 
     transaction.sign(cfg.sep24.keyPair)
 
-    val resp = server.submitTransaction(transaction)
-
-    if (!resp.isSuccess) {
+    val resp: TransactionResponse
+    try {
+      resp = server.submitTransaction(transaction)
+    } catch (e: BadRequestException) {
       throw Exception(
-        "Failed to submit transaction with code: ${resp?.extras?.resultCodes?.transactionResultCode}"
+        "Failed to submit transaction with code: ${e.problem?.extras?.resultCodes?.transactionResultCode}"
       )
     }
-
+    assert(resp.successful)
     return resp.hash
   }
 
diff --git a/platform/build.gradle.kts b/platform/build.gradle.kts
index c0e9adea2f..6980ad127a 100644
--- a/platform/build.gradle.kts
+++ b/platform/build.gradle.kts
@@ -26,6 +26,7 @@ dependencies {
   implementation(libs.aws.rds)
   implementation(libs.aws.sqs)
   implementation(libs.bcastle)
+  implementation(libs.bcutil)
   implementation(libs.commons.beanutils)
   implementation(libs.commons.cli)
   implementation(libs.commons.io)
diff --git a/platform/src/main/java/org/stellar/anchor/platform/config/PropertySep10Config.java b/platform/src/main/java/org/stellar/anchor/platform/config/PropertySep10Config.java
index 9a08dba94b..a950ec8d02 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/config/PropertySep10Config.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/config/PropertySep10Config.java
@@ -21,6 +21,7 @@
 import org.stellar.anchor.util.KeyUtil;
 import org.stellar.anchor.util.NetUtil;
 import org.stellar.sdk.*;
+import org.stellar.sdk.operations.ManageDataOperation;
 
 @Data
 public class PropertySep10Config implements Sep10Config, Validator {
@@ -112,7 +113,7 @@ void validateConfig(Errors errors) {
 
     if (isNotEmpty(webAuthDomain)) {
       try {
-        new ManageDataOperation.Builder(webAuthDomain, new byte[64]).build();
+        ManageDataOperation.builder().name(webAuthDomain).value(new byte[64]).build();
       } catch (IllegalArgumentException iaex) {
         errors.rejectValue(
             "webAuthDomain",
@@ -190,7 +191,10 @@ void validateCustodialAccounts(Errors errors) {
 
   private void validateDomain(Errors errors, String domain) {
     try {
-      new ManageDataOperation.Builder(String.format("%s %s", domain, "auth"), new byte[64]).build();
+      ManageDataOperation.builder()
+          .name(String.format("%s %s", domain, "auth"))
+          .value(new byte[64])
+          .build();
     } catch (IllegalArgumentException iaex) {
       errors.rejectValue(
           "homeDomain",
diff --git a/platform/src/main/java/org/stellar/anchor/platform/controller/sep/Sep10Controller.java b/platform/src/main/java/org/stellar/anchor/platform/controller/sep/Sep10Controller.java
index 041060dc10..a8639b647f 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/controller/sep/Sep10Controller.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/controller/sep/Sep10Controller.java
@@ -2,7 +2,6 @@
 
 import static org.stellar.anchor.util.Log.*;
 
-import java.io.IOException;
 import java.net.URISyntaxException;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
@@ -17,7 +16,7 @@
 import org.stellar.anchor.api.sep.sep10.ValidationResponse;
 import org.stellar.anchor.platform.condition.ConditionalOnAllSepsEnabled;
 import org.stellar.anchor.sep10.Sep10Service;
-import org.stellar.sdk.InvalidSep10ChallengeException;
+import org.stellar.sdk.exception.InvalidSep10ChallengeException;
 
 @RestController
 @CrossOrigin(origins = "*")
@@ -65,8 +64,7 @@ public ChallengeResponse createChallenge(
       produces = {MediaType.APPLICATION_JSON_VALUE},
       method = {RequestMethod.POST})
   public ValidationResponse validateChallenge(
-      @RequestParam(name = "transaction") String transaction)
-      throws InvalidSep10ChallengeException, IOException, SepValidationException {
+      @RequestParam(name = "transaction") String transaction) throws SepValidationException {
     debugF("POST /auth transaction={}", transaction);
     return validateChallenge(ValidationRequest.of(transaction));
   }
@@ -79,7 +77,7 @@ public ValidationResponse validateChallenge(
       method = {RequestMethod.POST})
   public ValidationResponse validateChallenge(
       @RequestBody(required = false) ValidationRequest validationRequest)
-      throws InvalidSep10ChallengeException, IOException, SepValidationException {
+      throws SepValidationException {
     debug("POST /auth details:", validationRequest);
     return sep10Service.validateChallenge(validationRequest);
   }
diff --git a/platform/src/main/java/org/stellar/anchor/platform/custody/CustodyPayment.java b/platform/src/main/java/org/stellar/anchor/platform/custody/CustodyPayment.java
index 0254f29c67..78bf20ddfc 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/custody/CustodyPayment.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/custody/CustodyPayment.java
@@ -67,7 +67,7 @@ public static CustodyPayment fromPayment(
       id = paymentOperation.get().getId().toString();
       to = paymentOperation.get().getTo();
       amount = paymentOperation.get().getAmount();
-      assetType = paymentOperation.get().getAsset().getType();
+      assetType = paymentOperation.get().getAssetType();
       assetName = paymentOperation.get().getAsset().toString();
 
       if (paymentOperation.get().getAsset() instanceof AssetTypeCreditAlphaNum) {
@@ -76,23 +76,22 @@ public static CustodyPayment fromPayment(
         assetCode = issuedAsset.getCode();
         assetIssuer = issuedAsset.getIssuer();
       } else if (paymentOperation.get().getAsset() instanceof AssetTypeNative) {
-        AssetTypeNative issuedAsset = (AssetTypeNative) paymentOperation.get().getAsset();
-        assetCode = issuedAsset.getType();
+        assetCode = paymentOperation.get().getAssetType(); // "native"
       }
 
       String sourceAccount =
           paymentOperation.get().getSourceAccount() != null
               ? paymentOperation.get().getSourceAccount()
-              : paymentOperation.get().getTransaction().get().getSourceAccount();
+              : paymentOperation.get().getTransaction().getSourceAccount();
       from =
           paymentOperation.get().getFrom() != null
               ? paymentOperation.get().getFrom()
               : sourceAccount;
-      Memo memo = paymentOperation.get().getTransaction().get().getMemo();
+      Memo memo = paymentOperation.get().getTransaction().getMemo();
 
       transactionMemo = MemoHelper.memoAsString(memo);
       transactionMemoType = MemoHelper.memoTypeAsString(memo);
-      transactionEnvelope = paymentOperation.get().getTransaction().get().getEnvelopeXdr();
+      transactionEnvelope = paymentOperation.get().getTransaction().getEnvelopeXdr();
     }
 
     return CustodyPayment.builder()
@@ -140,7 +139,7 @@ public static CustodyPayment fromPathPayment(
       id = pathPaymentOperation.get().getId().toString();
       to = pathPaymentOperation.get().getTo();
       amount = pathPaymentOperation.get().getAmount();
-      assetType = pathPaymentOperation.get().getAsset().getType();
+      assetType = pathPaymentOperation.get().getAssetType();
       assetName = pathPaymentOperation.get().getAsset().toString();
 
       if (pathPaymentOperation.get().getAsset() instanceof AssetTypeCreditAlphaNum) {
@@ -149,23 +148,22 @@ public static CustodyPayment fromPathPayment(
         assetCode = issuedAsset.getCode();
         assetIssuer = issuedAsset.getIssuer();
       } else if (pathPaymentOperation.get().getAsset() instanceof AssetTypeNative) {
-        AssetTypeNative issuedAsset = (AssetTypeNative) pathPaymentOperation.get().getAsset();
-        assetCode = issuedAsset.getType();
+        assetCode = pathPaymentOperation.get().getAssetType(); // "native"
       }
 
       String sourceAccount =
           pathPaymentOperation.get().getSourceAccount() != null
               ? pathPaymentOperation.get().getSourceAccount()
-              : pathPaymentOperation.get().getTransaction().get().getSourceAccount();
+              : pathPaymentOperation.get().getTransaction().getSourceAccount();
       from =
           pathPaymentOperation.get().getFrom() != null
               ? pathPaymentOperation.get().getFrom()
               : sourceAccount;
-      Memo memo = pathPaymentOperation.get().getTransaction().get().getMemo();
+      Memo memo = pathPaymentOperation.get().getTransaction().getMemo();
 
       transactionMemo = MemoHelper.memoAsString(memo);
       transactionMemoType = MemoHelper.memoTypeAsString(memo);
-      transactionEnvelope = pathPaymentOperation.get().getTransaction().get().getEnvelopeXdr();
+      transactionEnvelope = pathPaymentOperation.get().getTransaction().getEnvelopeXdr();
     }
 
     return CustodyPayment.builder()
diff --git a/platform/src/main/java/org/stellar/anchor/platform/job/TrustlineCheckJob.java b/platform/src/main/java/org/stellar/anchor/platform/job/TrustlineCheckJob.java
index 40f8454358..7239f7a7a8 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/job/TrustlineCheckJob.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/job/TrustlineCheckJob.java
@@ -2,7 +2,6 @@
 
 import static org.stellar.anchor.util.Log.info;
 
-import java.io.IOException;
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
 import org.springframework.scheduling.annotation.Scheduled;
@@ -13,6 +12,7 @@
 import org.stellar.anchor.platform.data.JdbcTransactionPendingTrust;
 import org.stellar.anchor.platform.data.JdbcTransactionPendingTrustRepo;
 import org.stellar.anchor.platform.rpc.NotifyTrustSetHandler;
+import org.stellar.sdk.exception.NetworkException;
 
 public class TrustlineCheckJob {
 
@@ -50,7 +50,7 @@ public void checkTrust() throws AnchorException {
         boolean trustlineConfigured;
         try {
           trustlineConfigured = horizon.isTrustlineConfigured(t.getAccount(), t.getAsset());
-        } catch (IOException ex) {
+        } catch (NetworkException ex) {
           trustlineConfigured = false;
         }
 
diff --git a/platform/src/main/java/org/stellar/anchor/platform/observer/ObservedPayment.java b/platform/src/main/java/org/stellar/anchor/platform/observer/ObservedPayment.java
index fa42401f7a..c1e436d3ac 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/observer/ObservedPayment.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/observer/ObservedPayment.java
@@ -6,7 +6,9 @@
 import org.stellar.anchor.api.asset.AssetInfo;
 import org.stellar.anchor.api.exception.SepException;
 import org.stellar.anchor.util.MemoHelper;
-import org.stellar.sdk.*;
+import org.stellar.sdk.AssetTypeCreditAlphaNum;
+import org.stellar.sdk.AssetTypeNative;
+import org.stellar.sdk.Memo;
 import org.stellar.sdk.responses.operations.PathPaymentBaseOperationResponse;
 import org.stellar.sdk.responses.operations.PaymentOperationResponse;
 
@@ -44,8 +46,7 @@ public static ObservedPayment fromPaymentOperationResponse(PaymentOperationRespo
       throws SepException {
     String assetCode = null, assetIssuer = null;
 
-    if (paymentOp.getAsset() instanceof AssetTypeCreditAlphaNum) {
-      AssetTypeCreditAlphaNum issuedAsset = (AssetTypeCreditAlphaNum) paymentOp.getAsset();
+    if (paymentOp.getAsset() instanceof AssetTypeCreditAlphaNum issuedAsset) {
       assetCode = issuedAsset.getCode();
       assetIssuer = issuedAsset.getIssuer();
     } else if (paymentOp.getAsset() instanceof AssetTypeNative) {
@@ -55,16 +56,16 @@ public static ObservedPayment fromPaymentOperationResponse(PaymentOperationRespo
     String sourceAccount =
         paymentOp.getSourceAccount() != null
             ? paymentOp.getSourceAccount()
-            : paymentOp.getTransaction().get().getSourceAccount();
+            : paymentOp.getTransaction().getSourceAccount();
     String from = paymentOp.getFrom() != null ? paymentOp.getFrom() : sourceAccount;
-    Memo memo = paymentOp.getTransaction().get().getMemo();
+    Memo memo = paymentOp.getTransaction().getMemo();
     return ObservedPayment.builder()
         .id(paymentOp.getId().toString())
         .type(Type.PAYMENT)
         .from(from)
         .to(paymentOp.getTo())
         .amount(paymentOp.getAmount())
-        .assetType(paymentOp.getAsset().getType())
+        .assetType(paymentOp.getAssetType())
         .assetCode(assetCode)
         .assetIssuer(assetIssuer)
         .assetName(paymentOp.getAsset().toString())
@@ -73,7 +74,7 @@ public static ObservedPayment fromPaymentOperationResponse(PaymentOperationRespo
         .transactionHash(paymentOp.getTransactionHash())
         .transactionMemo(MemoHelper.memoAsString(memo))
         .transactionMemoType(MemoHelper.memoTypeAsString(memo))
-        .transactionEnvelope(paymentOp.getTransaction().get().getEnvelopeXdr())
+        .transactionEnvelope(paymentOp.getTransaction().getEnvelopeXdr())
         .build();
   }
 
@@ -101,21 +102,21 @@ public static ObservedPayment fromPathPaymentOperationResponse(
     String sourceAccount =
         pathPaymentOp.getSourceAccount() != null
             ? pathPaymentOp.getSourceAccount()
-            : pathPaymentOp.getTransaction().get().getSourceAccount();
+            : pathPaymentOp.getTransaction().getSourceAccount();
     String from = pathPaymentOp.getFrom() != null ? pathPaymentOp.getFrom() : sourceAccount;
-    Memo memo = pathPaymentOp.getTransaction().get().getMemo();
+    Memo memo = pathPaymentOp.getTransaction().getMemo();
     return ObservedPayment.builder()
         .id(pathPaymentOp.getId().toString())
         .type(Type.PATH_PAYMENT)
         .from(from)
         .to(pathPaymentOp.getTo())
         .amount(pathPaymentOp.getAmount())
-        .assetType(pathPaymentOp.getAsset().getType())
+        .assetType(pathPaymentOp.getAssetType())
         .assetCode(assetCode)
         .assetIssuer(assetIssuer)
         .assetName(pathPaymentOp.getAsset().toString())
         .sourceAmount(pathPaymentOp.getSourceAmount())
-        .sourceAssetType(pathPaymentOp.getSourceAsset().getType())
+        .sourceAssetType(pathPaymentOp.getSourceAssetType())
         .sourceAssetCode(sourceAssetCode)
         .sourceAssetIssuer(sourceAssetIssuer)
         .sourceAssetName(pathPaymentOp.getSourceAsset().toString())
@@ -124,7 +125,7 @@ public static ObservedPayment fromPathPaymentOperationResponse(
         .transactionHash(pathPaymentOp.getTransactionHash())
         .transactionMemo(MemoHelper.memoAsString(memo))
         .transactionMemoType(MemoHelper.memoTypeAsString(memo))
-        .transactionEnvelope(pathPaymentOp.getTransaction().get().getEnvelopeXdr())
+        .transactionEnvelope(pathPaymentOp.getTransaction().getEnvelopeXdr())
         .build();
   }
 
diff --git a/platform/src/main/java/org/stellar/anchor/platform/observer/stellar/StellarPaymentObserver.java b/platform/src/main/java/org/stellar/anchor/platform/observer/stellar/StellarPaymentObserver.java
index 8e17e69011..71e965ff94 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/observer/stellar/StellarPaymentObserver.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/observer/stellar/StellarPaymentObserver.java
@@ -11,7 +11,6 @@
 import static org.stellar.anchor.util.StringHelper.isEmpty;
 
 import com.google.gson.annotations.SerializedName;
-import java.io.IOException;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.*;
@@ -37,6 +36,7 @@
 import org.stellar.anchor.util.ExponentialBackoffTimer;
 import org.stellar.anchor.util.Log;
 import org.stellar.sdk.Server;
+import org.stellar.sdk.exception.NetworkException;
 import org.stellar.sdk.requests.EventListener;
 import org.stellar.sdk.requests.PaymentsRequestBuilder;
 import org.stellar.sdk.requests.RequestBuilder;
@@ -148,8 +148,8 @@ SSEStream<OperationResponse> startSSEStream() {
         new EventListener<>() {
           @Override
           public void onEvent(OperationResponse operationResponse) {
-            if (operationResponse.getTransaction().isPresent()) {
-              metricLatestBlockRead.set(operationResponse.getTransaction().get().getLedger());
+            if (operationResponse.getTransaction() != null) {
+              metricLatestBlockRead.set(operationResponse.getTransaction().getLedger());
 
               if (isHealthy()) {
                 debugF("Received event {}", operationResponse.getId());
@@ -160,8 +160,7 @@ public void onEvent(OperationResponse operationResponse) {
                 try {
                   debugF("Dispatching event {}", operationResponse.getId());
                   handleEvent(operationResponse);
-                  metricLatestBlockProcessed.set(
-                      operationResponse.getTransaction().get().getLedger());
+                  metricLatestBlockProcessed.set(operationResponse.getTransaction().getLedger());
 
                 } catch (TransactionException ex) {
                   errorEx("Error handling events", ex);
@@ -336,14 +335,14 @@ String fetchLatestCursorFromNetwork() {
       infoF("Fetching the latest payments records. (limit={})", MIN_RESULTS);
       pageOpResponse =
           server.payments().order(RequestBuilder.Order.DESC).limit(MIN_RESULTS).execute();
-    } catch (IOException e) {
+    } catch (NetworkException e) {
       Log.errorEx("Error fetching the latest /payments result.", e);
       return null;
     }
 
     if (pageOpResponse == null
         || pageOpResponse.getRecords() == null
-        || pageOpResponse.getRecords().size() == 0) {
+        || pageOpResponse.getRecords().isEmpty()) {
       info("No payments found.");
       return null;
     }
@@ -353,7 +352,7 @@ String fetchLatestCursorFromNetwork() {
   }
 
   void handleEvent(OperationResponse operationResponse) {
-    if (!operationResponse.isTransactionSuccessful()) {
+    if (!operationResponse.getTransactionSuccessful()) {
       savePagingToken(operationResponse.getPagingToken());
       return;
     }
@@ -369,12 +368,11 @@ void handleEvent(OperationResponse operationResponse) {
         observedPayment = ObservedPayment.fromPathPaymentOperationResponse(pathPayment);
       }
     } catch (SepException ex) {
-      if (operationResponse.getTransaction().isPresent()) {
+      if (operationResponse.getTransaction() != null) {
         warn(
             String.format(
                 "Payment of id %s contains unsupported memo %s.",
-                operationResponse.getId(),
-                operationResponse.getTransaction().get().getMemo().toString()));
+                operationResponse.getId(), operationResponse.getTransaction().getMemo()));
       }
       warnEx(ex);
     }
diff --git a/platform/src/main/java/org/stellar/anchor/platform/rpc/DoStellarPaymentHandler.java b/platform/src/main/java/org/stellar/anchor/platform/rpc/DoStellarPaymentHandler.java
index 031e8f857c..8617e1fc4e 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/rpc/DoStellarPaymentHandler.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/rpc/DoStellarPaymentHandler.java
@@ -9,7 +9,6 @@
 import static org.stellar.anchor.api.sep.SepTransactionStatus.PENDING_TRUST;
 
 import com.google.common.collect.ImmutableSet;
-import java.io.IOException;
 import java.time.Instant;
 import java.util.Set;
 import org.stellar.anchor.api.exception.AnchorException;
@@ -32,6 +31,7 @@
 import org.stellar.anchor.sep24.Sep24TransactionStore;
 import org.stellar.anchor.sep31.Sep31TransactionStore;
 import org.stellar.anchor.sep6.Sep6TransactionStore;
+import org.stellar.sdk.exception.NetworkException;
 
 public class DoStellarPaymentHandler extends RpcTransactionStatusHandler<DoStellarPaymentRequest> {
 
@@ -103,7 +103,7 @@ protected SepTransactionStatus getNextStatus(
         default:
           break;
       }
-    } catch (IOException ex) {
+    } catch (NetworkException ex) {
       // assume trustline is not configured
     }
 
@@ -150,7 +150,7 @@ protected void updateTransactionWithRpcRequest(
         try {
           trustlineConfigured =
               horizon.isTrustlineConfigured(txn6.getToAccount(), txn6.getAmountOutAsset());
-        } catch (IOException ex) {
+        } catch (NetworkException ex) {
           trustlineConfigured = false;
         }
 
@@ -172,7 +172,7 @@ protected void updateTransactionWithRpcRequest(
         try {
           trustlineConfigured =
               horizon.isTrustlineConfigured(txn24.getToAccount(), txn24.getAmountOutAsset());
-        } catch (IOException ex) {
+        } catch (NetworkException ex) {
           trustlineConfigured = false;
         }
 
diff --git a/platform/src/main/java/org/stellar/anchor/platform/rpc/NotifyOnchainFundsReceivedHandler.java b/platform/src/main/java/org/stellar/anchor/platform/rpc/NotifyOnchainFundsReceivedHandler.java
index a652bd7948..463169e6c1 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/rpc/NotifyOnchainFundsReceivedHandler.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/rpc/NotifyOnchainFundsReceivedHandler.java
@@ -8,7 +8,6 @@
 import static org.stellar.anchor.util.Log.errorEx;
 
 import com.google.common.collect.ImmutableSet;
-import java.io.IOException;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -36,6 +35,7 @@
 import org.stellar.anchor.sep24.Sep24TransactionStore;
 import org.stellar.anchor.sep31.Sep31TransactionStore;
 import org.stellar.anchor.sep6.Sep6TransactionStore;
+import org.stellar.sdk.exception.NetworkException;
 import org.stellar.sdk.responses.operations.OperationResponse;
 
 public class NotifyOnchainFundsReceivedHandler
@@ -164,7 +164,7 @@ protected void updateTransactionWithRpcRequest(
         JdbcSep31Transaction txn31 = (JdbcSep31Transaction) txn;
         txn31.setFromAccount(txnOperations.get(0).getSourceAccount());
       }
-    } catch (IOException ex) {
+    } catch (NetworkException ex) {
       errorEx(String.format("Failed to retrieve stellar transaction by ID[%s]", stellarTxnId), ex);
       throw new InternalErrorException(
           String.format("Failed to retrieve Stellar transaction by ID[%s]", stellarTxnId), ex);
diff --git a/platform/src/main/java/org/stellar/anchor/platform/rpc/NotifyOnchainFundsSentHandler.java b/platform/src/main/java/org/stellar/anchor/platform/rpc/NotifyOnchainFundsSentHandler.java
index c3bb395857..1bbf62f71a 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/rpc/NotifyOnchainFundsSentHandler.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/rpc/NotifyOnchainFundsSentHandler.java
@@ -10,7 +10,6 @@
 import static org.stellar.anchor.util.Log.errorEx;
 
 import com.google.common.collect.ImmutableSet;
-import java.io.IOException;
 import java.time.Instant;
 import java.util.HashSet;
 import java.util.List;
@@ -33,6 +32,7 @@
 import org.stellar.anchor.sep24.Sep24TransactionStore;
 import org.stellar.anchor.sep31.Sep31TransactionStore;
 import org.stellar.anchor.sep6.Sep6TransactionStore;
+import org.stellar.sdk.exception.NetworkException;
 import org.stellar.sdk.responses.operations.OperationResponse;
 
 public class NotifyOnchainFundsSentHandler
@@ -110,7 +110,7 @@ protected void updateTransactionWithRpcRequest(
     try {
       List<OperationResponse> txnOperations = horizon.getStellarTxnOperations(stellarTxnId);
       addStellarTransaction(txn, stellarTxnId, txnOperations);
-    } catch (IOException ex) {
+    } catch (NetworkException ex) {
       errorEx(String.format("Failed to retrieve stellar transaction by ID[%s]", stellarTxnId), ex);
       throw new InternalErrorException(
           String.format("Failed to retrieve Stellar transaction by ID[%s]", stellarTxnId), ex);
diff --git a/platform/src/main/java/org/stellar/anchor/platform/service/RpcService.java b/platform/src/main/java/org/stellar/anchor/platform/service/RpcService.java
index b39d88975b..957ff74782 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/service/RpcService.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/service/RpcService.java
@@ -19,7 +19,7 @@
 import org.stellar.anchor.platform.config.RpcConfig;
 import org.stellar.anchor.platform.rpc.RpcMethodHandler;
 import org.stellar.anchor.platform.utils.RpcUtil;
-import org.stellar.sdk.requests.ErrorResponse;
+import org.stellar.sdk.exception.NetworkException;
 
 public class RpcService {
 
@@ -53,7 +53,7 @@ public List<RpcResponse> handle(List<RpcRequest> rpcRequests) {
                 return RpcUtil.getRpcErrorResponse(rc, ex);
               } catch (BadRequestException ex) {
                 return RpcUtil.getRpcErrorResponse(rc, ex);
-              } catch (ErrorResponse ex) {
+              } catch (NetworkException ex) {
                 var message =
                     ex.getMessage() + " Code: " + ex.getCode() + " , body: " + ex.getBody();
                 errorEx(
diff --git a/platform/src/test/kotlin/org/stellar/anchor/platform/observer/stellar/StellarPaymentObserverTest.kt b/platform/src/test/kotlin/org/stellar/anchor/platform/observer/stellar/StellarPaymentObserverTest.kt
index d9af9e001b..a89432dcf5 100644
--- a/platform/src/test/kotlin/org/stellar/anchor/platform/observer/stellar/StellarPaymentObserverTest.kt
+++ b/platform/src/test/kotlin/org/stellar/anchor/platform/observer/stellar/StellarPaymentObserverTest.kt
@@ -5,7 +5,6 @@ package org.stellar.anchor.platform.observer.stellar
 import com.google.gson.reflect.TypeToken
 import io.mockk.*
 import io.mockk.impl.annotations.MockK
-import java.io.IOException
 import java.util.*
 import javax.net.ssl.SSLProtocolException
 import org.junit.jupiter.api.Assertions.assertEquals
@@ -15,10 +14,11 @@ import org.junit.jupiter.api.Test
 import org.stellar.anchor.api.platform.HealthCheckStatus.RED
 import org.stellar.anchor.platform.config.PaymentObserverConfig.StellarPaymentObserverConfig
 import org.stellar.sdk.Server
+import org.stellar.sdk.exception.NetworkException
 import org.stellar.sdk.requests.RequestBuilder
 import org.stellar.sdk.requests.SSEStream
-import org.stellar.sdk.responses.GsonSingleton
 import org.stellar.sdk.responses.Page
+import org.stellar.sdk.responses.gson.GsonSingleton
 import org.stellar.sdk.responses.operations.OperationResponse
 
 class StellarPaymentObserverTest {
@@ -76,7 +76,7 @@ class StellarPaymentObserverTest {
         .order(RequestBuilder.Order.DESC)
         .limit(1)
         .execute()
-    } throws IOException("Some IO Problem happened!")
+    } throws NetworkException(null, "Some IO Problem happened!")
 
     gotCursor = stellarObserver.fetchStreamingCursor()
     verify(exactly = 2) { paymentStreamerCursorStore.load() }
diff --git a/platform/src/test/kotlin/org/stellar/anchor/platform/rpc/NotifyOnchainFundsReceivedHandlerTest.kt b/platform/src/test/kotlin/org/stellar/anchor/platform/rpc/NotifyOnchainFundsReceivedHandlerTest.kt
index f1efd54946..1839456cb5 100644
--- a/platform/src/test/kotlin/org/stellar/anchor/platform/rpc/NotifyOnchainFundsReceivedHandlerTest.kt
+++ b/platform/src/test/kotlin/org/stellar/anchor/platform/rpc/NotifyOnchainFundsReceivedHandlerTest.kt
@@ -4,7 +4,6 @@ import com.google.gson.reflect.TypeToken
 import io.micrometer.core.instrument.Counter
 import io.mockk.*
 import io.mockk.impl.annotations.MockK
-import java.io.IOException
 import java.time.Instant
 import kotlin.test.assertEquals
 import kotlin.test.assertTrue
@@ -46,6 +45,7 @@ import org.stellar.anchor.sep24.Sep24TransactionStore
 import org.stellar.anchor.sep31.Sep31TransactionStore
 import org.stellar.anchor.sep6.Sep6TransactionStore
 import org.stellar.anchor.util.GsonUtils
+import org.stellar.sdk.exception.NetworkException
 import org.stellar.sdk.responses.operations.OperationResponse
 import org.stellar.sdk.responses.operations.PaymentOperationResponse
 
@@ -577,7 +577,7 @@ class NotifyOnchainFundsReceivedHandlerTest {
     every { txn31Store.findByTransactionId(any()) } returns null
     every { txn24Store.save(capture(sep24TxnCapture)) } returns null
     every { horizon.getStellarTxnOperations(any()) } throws
-      IOException("Invalid stellar transaction")
+      NetworkException(400, "Invalid stellar transaction")
 
     val ex = assertThrows<InternalErrorException> { handler.handle(request) }
     assertEquals("Failed to retrieve Stellar transaction by ID[stellarTxId]", ex.message)
@@ -1037,7 +1037,7 @@ class NotifyOnchainFundsReceivedHandlerTest {
     every { txn31Store.findByTransactionId(any()) } returns null
     every { txn6Store.save(capture(sep6TxnCapture)) } returns null
     every { horizon.getStellarTxnOperations(any()) } throws
-      IOException("Invalid stellar transaction")
+      NetworkException(400, "Invalid stellar transaction")
 
     val ex = assertThrows<InternalErrorException> { handler.handle(request) }
     assertEquals("Failed to retrieve Stellar transaction by ID[stellarTxId]", ex.message)
diff --git a/platform/src/test/kotlin/org/stellar/anchor/platform/rpc/NotifyOnchainFundsSentHandlerTest.kt b/platform/src/test/kotlin/org/stellar/anchor/platform/rpc/NotifyOnchainFundsSentHandlerTest.kt
index 8512779991..5dbbf13962 100644
--- a/platform/src/test/kotlin/org/stellar/anchor/platform/rpc/NotifyOnchainFundsSentHandlerTest.kt
+++ b/platform/src/test/kotlin/org/stellar/anchor/platform/rpc/NotifyOnchainFundsSentHandlerTest.kt
@@ -4,7 +4,6 @@ import com.google.gson.reflect.TypeToken
 import io.micrometer.core.instrument.Counter
 import io.mockk.*
 import io.mockk.impl.annotations.MockK
-import java.io.IOException
 import java.time.Instant
 import kotlin.test.assertEquals
 import kotlin.test.assertTrue
@@ -45,6 +44,7 @@ import org.stellar.anchor.sep24.Sep24TransactionStore
 import org.stellar.anchor.sep31.Sep31TransactionStore
 import org.stellar.anchor.sep6.Sep6TransactionStore
 import org.stellar.anchor.util.GsonUtils
+import org.stellar.sdk.exception.NetworkException
 import org.stellar.sdk.responses.operations.OperationResponse
 import org.stellar.sdk.responses.operations.PaymentOperationResponse
 
@@ -163,7 +163,7 @@ class NotifyOnchainFundsSentHandlerTest {
     every { txn31Store.findByTransactionId(any()) } returns null
     every { txn24Store.save(capture(sep24TxnCapture)) } returns null
     every { horizon.getStellarTxnOperations(any()) } throws
-      IOException("Invalid stellar transaction")
+      NetworkException(400, "Invalid stellar transaction")
 
     val ex = assertThrows<InternalErrorException> { handler.handle(request) }
     assertEquals("Failed to retrieve Stellar transaction by ID[stellarTxId]", ex.message)
diff --git a/wallet-reference-server/build.gradle.kts b/wallet-reference-server/build.gradle.kts
index 25992c1319..5b81c58198 100644
--- a/wallet-reference-server/build.gradle.kts
+++ b/wallet-reference-server/build.gradle.kts
@@ -11,6 +11,7 @@ dependencies {
   implementation(libs.bundles.ktor)
   implementation(libs.bundles.ktor.client)
   implementation(libs.bcastle)
+  implementation(libs.bcutil)
   implementation(libs.google.gson)
   implementation(libs.hoplite.core)
   implementation(libs.hoplite.yaml)