From 2c69d58f261fb2489f989f4b6c80dd12fee34355 Mon Sep 17 00:00:00 2001
From: Mayukha Vadari <mvadari@gmail.com>
Date: Wed, 22 Jul 2026 18:09:19 -0400
Subject: [PATCH] export error reason via submit/simulate

---
 include/xrpl/protocol/jss.h                     | 1 +
 src/xrpld/app/misc/NetworkOPs.cpp               | 1 +
 src/xrpld/rpc/detail/TransactionSign.cpp        | 1 +
 src/xrpld/rpc/handlers/transaction/Simulate.cpp | 2 ++
 src/xrpld/rpc/handlers/transaction/Submit.cpp   | 1 +
 5 files changed, 6 insertions(+)

diff --git a/include/xrpl/protocol/jss.h b/include/xrpl/protocol/jss.h
index 63e877ca31..95864f0b41 100644
--- a/include/xrpl/protocol/jss.h
+++ b/include/xrpl/protocol/jss.h
@@ -239,6 +239,7 @@ JSS(enabled);                        // out: AmendmentTable
 JSS(engine_result);                  // out: NetworkOPs, TransactionSign, Submit
 JSS(engine_result_code);             // out: NetworkOPs, TransactionSign, Submit
 JSS(engine_result_message);          // out: NetworkOPs, TransactionSign, Submit
+JSS(engine_result_reason);           // out: NetworkOPs, TransactionSign, Submit
 JSS(entire_set);                     // out: get_aggregate_price
 JSS(ephemeral_key);                  // out: ValidatorInfo
                                      // in/out: Manifest
diff --git a/src/xrpld/app/misc/NetworkOPs.cpp b/src/xrpld/app/misc/NetworkOPs.cpp
index 4b0091dff6..b0f55e2d9f 100644
--- a/src/xrpld/app/misc/NetworkOPs.cpp
+++ b/src/xrpld/app/misc/NetworkOPs.cpp
@@ -3321,6 +3321,7 @@ NetworkOPsImp::transJson(
     jvObj[jss::engine_result] = sToken;
     jvObj[jss::engine_result_code] = result;
     jvObj[jss::engine_result_message] = sHuman;
+    jvObj[jss::engine_result_reason] = result.reason;
 
     if (transaction->getTxnType() == ttOFFER_CREATE)
     {
diff --git a/src/xrpld/rpc/detail/TransactionSign.cpp b/src/xrpld/rpc/detail/TransactionSign.cpp
index e1c5180b5c..ceaad9ab23 100644
--- a/src/xrpld/rpc/detail/TransactionSign.cpp
+++ b/src/xrpld/rpc/detail/TransactionSign.cpp
@@ -804,6 +804,7 @@ transactionFormatResultImpl(Transaction::pointer tpTrans, unsigned apiVersion)
             jvResult[jss::engine_result] = sToken;
             jvResult[jss::engine_result_code] = tpTrans->getResult();
             jvResult[jss::engine_result_message] = sHuman;
+            jvResult[jss::engine_result_reason] = tpTrans->getResult().reason;
         }
     }
     catch (std::exception&)
diff --git a/src/xrpld/rpc/handlers/transaction/Simulate.cpp b/src/xrpld/rpc/handlers/transaction/Simulate.cpp
index 0f163c7356..f52720b376 100644
--- a/src/xrpld/rpc/handlers/transaction/Simulate.cpp
+++ b/src/xrpld/rpc/handlers/transaction/Simulate.cpp
@@ -264,6 +264,7 @@ simulateTxn(RPC::JsonContext& context, std::shared_ptr<Transaction> transaction)
         jvResult[jss::engine_result] = token;
         jvResult[jss::engine_result_code] = result.ter;
         jvResult[jss::engine_result_message] = message;
+        jvResult[jss::engine_result_reason] = result.ter.reason;
     }
     else
     {
@@ -272,6 +273,7 @@ simulateTxn(RPC::JsonContext& context, std::shared_ptr<Transaction> transaction)
         jvResult[jss::engine_result] = "unknown";
         jvResult[jss::engine_result_code] = result.ter;
         jvResult[jss::engine_result_message] = "unknown";
+        jvResult[jss::engine_result_reason] = "unknown";
         // LCOV_EXCL_STOP
     }
 
diff --git a/src/xrpld/rpc/handlers/transaction/Submit.cpp b/src/xrpld/rpc/handlers/transaction/Submit.cpp
index 79f3680684..769c75799c 100644
--- a/src/xrpld/rpc/handlers/transaction/Submit.cpp
+++ b/src/xrpld/rpc/handlers/transaction/Submit.cpp
@@ -154,6 +154,7 @@ doSubmit(RPC::JsonContext& context)
             jvResult[jss::engine_result] = sToken;
             jvResult[jss::engine_result_code] = transaction->getResult();
             jvResult[jss::engine_result_message] = sHuman;
+            jvResult[jss::engine_result_reason] = transaction->getResult().reason;
 
             auto const submitResult = transaction->getSubmitResult();