From d80034a1a4ec0df7faa8662df49be4eb1872abf7 Mon Sep 17 00:00:00 2001
From: Matthew <ramsden@hey.com>
Date: Mon, 10 Aug 2026 11:13:45 -0500
Subject: [PATCH] fix: return structured insufficient funds errors

---
 bdk-ffi/src/error.rs       |  8 +++++---
 bdk-ffi/src/tests/error.rs | 25 ++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/bdk-ffi/src/error.rs b/bdk-ffi/src/error.rs
index ea7f48cd9..80bec672c 100644
--- a/bdk-ffi/src/error.rs
+++ b/bdk-ffi/src/error.rs
@@ -1082,9 +1082,11 @@ impl From<BdkCreateTxError> for CreateTxError {
             BdkCreateTxError::OutputBelowDustLimit(index) => CreateTxError::OutputBelowDustLimit {
                 index: index as u64,
             },
-            BdkCreateTxError::CoinSelection(e) => CreateTxError::CoinSelection {
-                error_message: e.to_string(),
-            },
+            BdkCreateTxError::CoinSelection(e) => {
+                let needed = e.needed.to_sat();
+                let available = e.available.to_sat();
+                CreateTxError::InsufficientFunds { needed, available }
+            }
             BdkCreateTxError::NoRecipients => CreateTxError::NoRecipients,
             BdkCreateTxError::Psbt(e) => CreateTxError::Psbt {
                 error_message: e.to_string(),
diff --git a/bdk-ffi/src/tests/error.rs b/bdk-ffi/src/tests/error.rs
index d130696d9..a232f7873 100644
--- a/bdk-ffi/src/tests/error.rs
+++ b/bdk-ffi/src/tests/error.rs
@@ -1,8 +1,11 @@
 use crate::error::{
-    Bip32Error, Bip39Error, CannotConnectError, DescriptorError, DescriptorKeyError, ElectrumError,
-    EsploraError, ExtractTxError, PsbtError, PsbtParseError, RequestBuilderError, SignerError,
-    TransactionError, TxidParseError,
+    Bip32Error, Bip39Error, CannotConnectError, CreateTxError, DescriptorError, DescriptorKeyError,
+    ElectrumError, EsploraError, ExtractTxError, PsbtError, PsbtParseError, RequestBuilderError,
+    SignerError, TransactionError, TxidParseError,
 };
+use bdk_wallet::bitcoin::Amount;
+use bdk_wallet::coin_selection::InsufficientFunds as BdkInsufficientFunds;
+use bdk_wallet::error::CreateTxError as BdkCreateTxError;
 
 #[test]
 fn test_error_bip32() {
@@ -104,6 +107,22 @@ fn test_error_cannot_connect() {
     assert_eq!(format!("{}", error), "cannot include height: 42");
 }
 
+#[test]
+fn test_error_create_tx_insufficient_funds_conversion() {
+    let error = BdkCreateTxError::CoinSelection(BdkInsufficientFunds {
+        needed: Amount::from_sat(50_000),
+        available: Amount::from_sat(30_000),
+    });
+
+    match CreateTxError::from(error) {
+        CreateTxError::InsufficientFunds { needed, available } => {
+            assert_eq!(needed, 50_000);
+            assert_eq!(available, 30_000);
+        }
+        other => panic!("expected insufficient funds error, got {:?}", other),
+    }
+}
+
 #[test]
 fn test_error_descriptor() {
     let cases = vec![