From c5636591addda6bccdb88b252ea52dd2145ba319 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 10 Jun 2026 10:20:29 -0700
Subject: [PATCH 01/30] Update C client to revision that supports enhanced
 error messages.

---
 aerospike-client-c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/aerospike-client-c b/aerospike-client-c
index 49e704236d..ae201bf16c 160000
--- a/aerospike-client-c
+++ b/aerospike-client-c
@@ -1 +1 @@
-Subproject commit 49e704236d38667d0e77bf2d8d9c95b10250230b
+Subproject commit ae201bf16c02977d16a9bc90931184fe6a40cf00

From a8b5ab9ff9df6571286e0f5694e5bc09d39f2e1f Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 10 Jun 2026 10:48:23 -0700
Subject: [PATCH 02/30] Add missing op local variable to represent op code.

---
 .../operations/string_operations.py           | 39 ++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/aerospike_helpers/operations/string_operations.py b/aerospike_helpers/operations/string_operations.py
index ddc2ec45ea..0c89b1a7ce 100644
--- a/aerospike_helpers/operations/string_operations.py
+++ b/aerospike_helpers/operations/string_operations.py
@@ -34,6 +34,7 @@
 Python strings, but they cannot embedded NULL bytes.
 """
 
+import aerospike
 from ..string_helpers import NumericType, RegexFlags, StringPolicy, __generate_docstrings_for_all_func_members
 import sys
 
@@ -55,6 +56,7 @@ def strlen(bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_STRLEN
     return locals()
 
 
@@ -71,6 +73,7 @@ def substr(bin_name: str, start: int, length: int | None = None, ctx: TypeCTX =
         length (int): Number of codepoints to return.
         {ctx}
     """
+    op = aerospike._OP_STRING_SUBSTR
     return locals()
 
 
@@ -85,6 +88,7 @@ def char_at(bin_name: str, index: int, ctx: TypeCTX = None):
         index (int): Index of the codepoint to return.
         {ctx}
     """
+    op = aerospike._OP_STRING_CHAR_AT
     return locals()
 
 
@@ -101,6 +105,7 @@ def find(bin_name: str, needle: str, occurrence: int = 1, ctx: TypeCTX = None):
         index (int): Index of the codepoint to return.
         {ctx}
     """
+    op = aerospike._OP_STRING_FIND
     return locals()
 
 
@@ -114,6 +119,7 @@ def contains(bin_name: str, needle: int, ctx: TypeCTX = None):
         {needle_get}
         {ctx}
     """
+    op = aerospike._OP_STRING_CONTAINS
     return locals()
 
 
@@ -128,6 +134,7 @@ def starts_with(bin_name: str, prefix: str, ctx: TypeCTX = None):
         prefix (str): The string to search for.
         {ctx}
     """
+    op = aerospike._OP_STRING_STARTS_WITH
     return locals()
 
 
@@ -142,6 +149,7 @@ def ends_with(bin_name: str, suffix: str, ctx: TypeCTX = None):
         suffix (str): The string to search for.
         {ctx}
     """
+    op = aerospike._OP_STRING_ENDS_WITH
     return locals()
 
 
@@ -155,6 +163,7 @@ def to_integer(bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_TO_INTEGER
     return locals()
 
 
@@ -168,6 +177,7 @@ def to_double(bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_TO_DOUBLE
     return locals()
 
 
@@ -181,6 +191,7 @@ def byte_length(bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_BYTE_LENGTH
     return locals()
 
 
@@ -195,6 +206,7 @@ def is_numeric(bin_name: str, numeric_type: NumericType = NumericType.ANY, ctx:
         numeric_type (:py:class:`~aerospike_helpers.string_helpers.NumericType`): The numeric type to filter for.
         {ctx}
     """
+    op = aerospike._OP_STRING_IS_NUMERIC
     return locals()
 
 
@@ -208,6 +220,7 @@ def is_upper(bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_IS_UPPER
     return locals()
 
 
@@ -221,6 +234,7 @@ def is_lower(bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_IS_LOWER
     return locals()
 
 
@@ -234,6 +248,7 @@ def to_blob(bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_TO_BLOB
     return locals()
 
 
@@ -248,6 +263,7 @@ def split(bin_name: str, separator: str = None, ctx: TypeCTX = None):
             becomes one string element in the returned list.
         {ctx}
     """
+    op = aerospike._OP_STRING_SPLIT
     return locals()
 
 
@@ -261,6 +277,7 @@ def base64_decode(bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_B64_DECODE
     return locals()
 
 
@@ -276,6 +293,7 @@ def regex_compare(bin_name: str, pattern: str, regex_flags: RegexFlags = RegexFl
         {regex_flags}
         {ctx}
     """
+    op = aerospike._OP_STRING_REGEX_COMPARE
     return locals()
 
 
@@ -292,6 +310,7 @@ def insert(policy: StringPolicy, bin_name: str, index: int, value: str, ctx: Typ
         value (str): The value to insert.
         {ctx}
     """
+    op = aerospike._OP_STRING_INSERT
     return locals()
 
 
@@ -309,6 +328,7 @@ def overwrite(policy: StringPolicy, bin_name: str, index: int, value: str, ctx:
         value (str): The value to overwrite.
         {ctx}
     """
+    op = aerospike._OP_STRING_OVERWRITE
     return locals()
 
 
@@ -323,6 +343,7 @@ def concat(policy: StringPolicy, bin_name: str, value: str, ctx: TypeCTX = None)
         value (str): The value to append.
         {ctx}
     """
+    op = aerospike._OP_STRING_CONCAT
     return locals()
 
 
@@ -338,7 +359,8 @@ def concat_list(policy: StringPolicy, bin_name: str, value_list: list[str], ctx:
         value_list (str): The list of values to append.
         {ctx}
     """
-    pass
+    op = aerospike._OP_STRING_CONCAT_LIST
+    return locals()
 
 
 def snip(policy: StringPolicy, bin_name: str, start: int, end: int | None = None, ctx: TypeCTX = None):
@@ -354,6 +376,7 @@ def snip(policy: StringPolicy, bin_name: str, start: int, end: int | None = None
             remove from start through the end of the string.
         {ctx}
     """
+    op = aerospike._OP_STRING_SNIP
     return locals()
 
 
@@ -370,6 +393,7 @@ def replace(policy: StringPolicy, bin_name: str, needle: str, replacement: str,
         {replacement}
         {ctx}
     """
+    op = aerospike._OP_STRING_REPLACE
     return locals()
 
 
@@ -386,6 +410,7 @@ def replace_all(policy: StringPolicy, bin_name: str, needle: str, replacement: s
         {replacement}
         {ctx}
     """
+    op = aerospike._OP_STRING_REPLACE_ALL
     return locals()
 
 
@@ -399,6 +424,7 @@ def upper(policy: StringPolicy, bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_UPPER
     return locals()
 
 
@@ -412,6 +438,7 @@ def lower(policy: StringPolicy, bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_LOWER
     return locals()
 
 
@@ -427,6 +454,7 @@ def casefold(policy: StringPolicy, bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_CASE_FOLD
     return locals()
 
 
@@ -442,6 +470,7 @@ def normalize_nfc(policy: StringPolicy, bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_NORMALIZE_NFC
     return locals()
 
 
@@ -456,6 +485,7 @@ def trim_start(policy: StringPolicy, bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_TRIM_START
     return locals()
 
 
@@ -470,6 +500,7 @@ def trim_end(policy: StringPolicy, bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_TRIM_END
     return locals()
 
 
@@ -483,6 +514,7 @@ def trim(policy: StringPolicy, bin_name: str, ctx: TypeCTX = None):
         {bin_name}
         {ctx}
     """
+    op = aerospike._OP_STRING_TRIM
     return locals()
 
 
@@ -500,6 +532,7 @@ def pad_start(policy: StringPolicy, bin_name: str, target_length: int, pad_strin
         {pad_string}
         {ctx}
     """
+    op = aerospike._OP_STRING_PAD_START
     return locals()
 
 
@@ -517,6 +550,7 @@ def pad_end(policy: StringPolicy, bin_name: str, target_length: int, pad_string:
         {pad_string}
         {ctx}
     """
+    op = aerospike._OP_STRING_PAD_END
     return locals()
 
 
@@ -531,6 +565,7 @@ def repeat(policy: StringPolicy, bin_name: str, count: int, ctx: TypeCTX = None)
         count (int): The number of times to repeat the string. Must be non-negative.
         {ctx}
     """
+    op = aerospike._OP_STRING_REPEAT
     return locals()
 
 
@@ -557,6 +592,7 @@ def regex_replace(
         {regex_flags}
         {ctx}
     """
+    op = aerospike._OP_STRING_REGEX_REPLACE
     return locals()
 
 
@@ -571,6 +607,7 @@ def to_string(bin_name: str):
 
         {bin_name}
     """
+    op = aerospike._OP_STRING_TO_STRING
     return locals()
 
 

From 21f0d739a0eabf77593daa5e2be4fff43ac9fca2 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 15 Jun 2026 14:49:23 -0700
Subject: [PATCH 03/30] Document new subcode attribute in exception class.

---
 doc/exception.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/doc/exception.rst b/doc/exception.rst
index 3ad3f3b2f1..7725705cba 100644
--- a/doc/exception.rst
+++ b/doc/exception.rst
@@ -40,6 +40,13 @@ Base Class
 
         The associated status code.
 
+    .. py:attribute:: subcode
+
+        Server error detail subcode. When ``error_detail_verbosity`` is greater than or equal to ``1`` on the command's
+        base policy and the server returns structured error details, this field contains the numeric subcode.
+
+        Set to ``0`` when no subcode was returned.
+
     .. py:attribute:: msg
 
         The human-readable error message.

From e66716d77aba55428db4b8ea83c1716991401740 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 15 Jun 2026 14:56:08 -0700
Subject: [PATCH 04/30] Add docs for base policy error_detail_verbosity option

---
 doc/client.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/doc/client.rst b/doc/client.rst
index 2e18adf07f..28b4c95022 100755
--- a/doc/client.rst
+++ b/doc/client.rst
@@ -1751,6 +1751,17 @@ Base Policies
 
             Default: :py:obj:`None`
 
+        * **error_detail_verbosity** (:class:`int`)
+
+            Request server error detail fields in responses.
+
+            ``0`` - disabled (no error details returned). Default.
+            ``1`` - return subcode only.
+            ``2`` - return subcode and human-readable message.
+
+            When enabled and the server returns error details, :py:attr:`aerospike.exception.AerospikeError.subcode` will contain the
+            numeric subcode and :py:attr:`aerospike.exception.AerospikeError.msg` will contain the server-authored message.
+
 .. _aerospike_write_policies:
 
 Write Policies

From 70cf6842988175eafecaed3593a38ceaac710db2 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 15 Jun 2026 15:02:24 -0700
Subject: [PATCH 05/30] Fix list formatting for error_detail_verbosity

---
 doc/client.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/client.rst b/doc/client.rst
index 28b4c95022..85afa909d0 100755
--- a/doc/client.rst
+++ b/doc/client.rst
@@ -1755,9 +1755,9 @@ Base Policies
 
             Request server error detail fields in responses.
 
-            ``0`` - disabled (no error details returned). Default.
-            ``1`` - return subcode only.
-            ``2`` - return subcode and human-readable message.
+            - ``0``: disabled (no error details returned). Default.
+            - ``1``: return subcode only.
+            - ``2``: return subcode and human-readable message.
 
             When enabled and the server returns error details, :py:attr:`aerospike.exception.AerospikeError.subcode` will contain the
             numeric subcode and :py:attr:`aerospike.exception.AerospikeError.msg` will contain the server-authored message.

From c2192d92e2d06810f1c8348224af14e5f38462d5 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 08:29:36 -0700
Subject: [PATCH 06/30] Add happy path tests. Add missing subcode attribute to
 AerospikeError class.

---
 aerospike-stubs/exception.pyi            |  1 +
 test/new_tests/test_exception_subcode.py | 52 ++++++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 test/new_tests/test_exception_subcode.py

diff --git a/aerospike-stubs/exception.pyi b/aerospike-stubs/exception.pyi
index c3f11713da..e5a3b1fc52 100644
--- a/aerospike-stubs/exception.pyi
+++ b/aerospike-stubs/exception.pyi
@@ -3,6 +3,7 @@ from typing import Union
 class AerospikeError(Exception):
     # When attributes are first assigned to exception class, they have an initial value of None
     code: Union[int, None]
+    subcode: int
     msg: Union[str, None]
     file: Union[str, None]
     line: Union[int, None]
diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
new file mode 100644
index 0000000000..8e6b59e576
--- /dev/null
+++ b/test/new_tests/test_exception_subcode.py
@@ -0,0 +1,52 @@
+import pytest
+from .conftest import KEYS
+from aerospike import exception as e
+from aerospike_helpers.operations import list_operations as list_ops
+from . import as_errors
+
+
+KEY = KEYS[0]
+OPS = [
+    list_ops.list_get_by_index(99)
+]
+ERROR_DETAIL_VERBOSITY_SETTING = "error_detail_verbosity"
+
+
+class TestExceptionSubcode:
+    # TODO: need to reuse fixture in conftest.py using indirect params to set num of records
+    def setup(self):
+        self.as_connection.put(KEY, bins={"a": []})
+        yield
+        self.as_connection.remove(KEY)
+
+    @pytest.mark.parametrize(
+        "policy",
+        [
+            {},
+            {ERROR_DETAIL_VERBOSITY_SETTING: 0},
+            {ERROR_DETAIL_VERBOSITY_SETTING: 1},
+            {ERROR_DETAIL_VERBOSITY_SETTING: 2},
+        ]
+    )
+    def test_minimum_error_verbosity(self, policy: dict):
+        with pytest.raises(e.InvalidRequest) as excinfo:
+            self.as_connection.operate(KEYS[0], OPS, policy=policy)
+
+        # Make sure there's no regression with the parent error code
+        assert excinfo.value.code == as_errors.AEROSPIKE_ERR_REQUEST_INVALID
+        if policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0:
+            assert excinfo.value.subcode == 0
+        else:
+            assert excinfo.value.subcode > 0
+
+        SUBCODE_IN_MESSAGE = "subcode="
+        if policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0:
+            assert SUBCODE_IN_MESSAGE not in excinfo.value.msg
+        elif policy[ERROR_DETAIL_VERBOSITY_SETTING] == 1:
+            # Make sure there's no regression with the server error message
+            # with lower verbosity
+            assert SUBCODE_IN_MESSAGE in excinfo.value.msg
+        else:
+            # There should be a message before the subcode
+            SUBCODE_IN_QUOTES = "({})".format(SUBCODE_IN_MESSAGE)
+            assert SUBCODE_IN_QUOTES in excinfo.value.msg

From 6a2ad1131f53ec01290f577a23fc06ce9f441d81 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 08:35:42 -0700
Subject: [PATCH 07/30] Add negative test for invalid verbosity. Don't see any
 client side check for verbosity levels > 2, so I guess the server will return
 an error.

---
 test/new_tests/test_exception_subcode.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
index 8e6b59e576..f4aa104c45 100644
--- a/test/new_tests/test_exception_subcode.py
+++ b/test/new_tests/test_exception_subcode.py
@@ -50,3 +50,10 @@ def test_minimum_error_verbosity(self, policy: dict):
             # There should be a message before the subcode
             SUBCODE_IN_QUOTES = "({})".format(SUBCODE_IN_MESSAGE)
             assert SUBCODE_IN_QUOTES in excinfo.value.msg
+
+    def test_invalid_verbosity(self):
+        policy = {
+            ERROR_DETAIL_VERBOSITY_SETTING: 3
+        }
+        with pytest.raises(e.ServerError):
+            self.as_connection.operate(KEYS[0], OPS, policy=policy)

From c5c7d937ba9b3dddcdf51c81bd7341514cb844db Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 09:04:25 -0700
Subject: [PATCH 08/30] Add implementation for error_detail_verbosity

---
 src/main/policy.c        |  1 +
 src/main/policy_config.c | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/src/main/policy.c b/src/main/policy.c
index f80cf2e9c0..231cca2890 100644
--- a/src/main/policy.c
+++ b/src/main/policy.c
@@ -322,6 +322,7 @@ static inline as_status pyobject_to_policy_base(AerospikeClient *self,
     POLICY_SET_FIELD(sleep_between_retries, uint32_t);
     POLICY_SET_FIELD(compress, bool);
     POLICY_SET_FIELD(connect_timeout, uint32_t);
+    POLICY_SET_FIELD(error_detail_verbosity, uint8_t);
 
     // Setting txn field to a non-NULL value in a query or scan policy is a no-op,
     // so this is safe to call for a scan/query policy's base policy
diff --git a/src/main/policy_config.c b/src/main/policy_config.c
index 6a76b45818..c9cfba056a 100644
--- a/src/main/policy_config.c
+++ b/src/main/policy_config.c
@@ -18,6 +18,7 @@
 #include "policy_config.h"
 #include "types.h"
 #include "policy.h"
+#include "conversions.h"
 
 as_status set_optional_key(as_policy_key *target_ptr, PyObject *py_policy,
                            const char *name);
@@ -900,6 +901,27 @@ as_status set_batch_remove_policy(as_error *err,
     return AEROSPIKE_OK;
 }
 
+as_status set_optional_uint8_property(uint8_t *target_ptr, PyObject *py_policy,
+                                      const char *name)
+{
+    // Assume py_policy is a Python dictionary
+    PyObject *py_policy_val = PyDict_GetItemString(py_policy, name);
+    if (!py_policy_val) {
+        // Key doesn't exist in policy
+        return AEROSPIKE_OK;
+    }
+
+    uint8_t int_value = convert_pyobject_to_uint8_t(py_policy_val);
+
+    if (PyErr_Occurred()) {
+        PyErr_Clear();
+        return AEROSPIKE_ERR_PARAM;
+    }
+
+    *target_ptr = int_value;
+    return AEROSPIKE_OK;
+}
+
 as_status set_base_policy(as_policy_base *base_policy, PyObject *py_policy)
 {
 
@@ -956,6 +978,11 @@ as_status set_base_policy(as_policy_base *base_policy, PyObject *py_policy)
         return status;
     }
 
+    status = set_optional_uint8_property(&base_policy->error_detail_verbosity,
+                                         py_policy, "error_detail_verbosity");
+    if (status != AEROSPIKE_OK) {
+        return status;
+    }
     return AEROSPIKE_OK;
 }
 

From 3ec37bef9ad0f3934dd4ffb283a9c555f0a783c5 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 09:11:49 -0700
Subject: [PATCH 09/30] Finish implementation for AerospikeError's subcode
 attribute.

---
 src/main/conversions.c | 19 +++++++++++++------
 src/main/exception.c   |  4 ++--
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/main/conversions.c b/src/main/conversions.c
index 61d55e0570..1f8e3e0339 100644
--- a/src/main/conversions.c
+++ b/src/main/conversions.c
@@ -54,11 +54,15 @@
 #define PY_KEYT_KEY 2
 #define PY_KEYT_DIGEST 3
 
-#define PY_EXCEPTION_CODE 0
-#define PY_EXCEPTION_MSG 1
-#define PY_EXCEPTION_FILE 2
-#define PY_EXCEPTION_LINE 3
-#define AS_PY_EXCEPTION_IN_DOUBT 4
+enum {
+    PY_EXCEPTION_CODE = 0,
+    PY_EXCEPTION_MSG,
+    PY_EXCEPTION_FILE,
+    PY_EXCEPTION_LINE,
+    AS_PY_EXCEPTION_IN_DOUBT,
+    PY_EXCEPTION_SUBCODE,
+    EXCEPTION_TUPLE_MEMBER_COUNT
+};
 
 #define CTX_KEY "ctx"
 #define CDT_CTX_ORDER_KEY "order_key"
@@ -2287,12 +2291,15 @@ void error_to_pyobject(const as_error *err, PyObject **obj)
     PyObject *py_in_doubt = err->in_doubt ? Py_True : Py_False;
     Py_INCREF(py_in_doubt);
 
-    PyObject *py_err = PyTuple_New(5);
+    PyObject *py_subcode = PyLong_FromLong(err->subcode);
+
+    PyObject *py_err = PyTuple_New(EXCEPTION_TUPLE_MEMBER_COUNT);
     PyTuple_SetItem(py_err, PY_EXCEPTION_CODE, py_code);
     PyTuple_SetItem(py_err, PY_EXCEPTION_MSG, py_message);
     PyTuple_SetItem(py_err, PY_EXCEPTION_FILE, py_file);
     PyTuple_SetItem(py_err, PY_EXCEPTION_LINE, py_line);
     PyTuple_SetItem(py_err, AS_PY_EXCEPTION_IN_DOUBT, py_in_doubt);
+    PyTuple_SetItem(py_err, PY_EXCEPTION_SUBCODE, py_subcode);
     *obj = py_err;
 }
 
diff --git a/src/main/exception.c b/src/main/exception.c
index 9ec4b89066..e1db02a537 100644
--- a/src/main/exception.c
+++ b/src/main/exception.c
@@ -68,8 +68,8 @@ struct exception_def {
 #define NO_ERROR_CODE 0
 
 // Same order as the tuple of args passed into the exception
-const char *const aerospike_err_attrs[] = {"code", "msg",      "file",
-                                           "line", "in_doubt", NULL};
+const char *const aerospike_err_attrs[] = {
+    "code", "msg", "file", "line", "in_doubt", "subcode", NULL};
 const char *const record_err_attrs[] = {"key", "bin", NULL};
 const char *const index_err_attrs[] = {"name", NULL};
 const char *const udf_err_attrs[] = {"module", "func", NULL};

From 961ddbed1da18d60e7581645c7d47a6bb2a7df0d Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 11:56:06 -0700
Subject: [PATCH 10/30] Address test syntax error.

---
 test/new_tests/test_exception_subcode.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
index f4aa104c45..a89e81db2b 100644
--- a/test/new_tests/test_exception_subcode.py
+++ b/test/new_tests/test_exception_subcode.py
@@ -1,5 +1,6 @@
 import pytest
-from .conftest import KEYS
+from .conftest import KEYS, BIN_NAME
+import aerospike
 from aerospike import exception as e
 from aerospike_helpers.operations import list_operations as list_ops
 from . import as_errors
@@ -7,7 +8,7 @@
 
 KEY = KEYS[0]
 OPS = [
-    list_ops.list_get_by_index(99)
+    list_ops.list_get_by_index(BIN_NAME, index=99, return_type=aerospike.LIST_RETURN_VALUE)
 ]
 ERROR_DETAIL_VERBOSITY_SETTING = "error_detail_verbosity"
 
@@ -15,7 +16,7 @@
 class TestExceptionSubcode:
     # TODO: need to reuse fixture in conftest.py using indirect params to set num of records
     def setup(self):
-        self.as_connection.put(KEY, bins={"a": []})
+        self.as_connection.put(KEY, bins={BIN_NAME: []})
         yield
         self.as_connection.remove(KEY)
 

From 8ee462f24dbc9755e2ab78e75a20d9024eeb9681 Mon Sep 17 00:00:00 2001
From: juliannguyen4 <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 19:13:33 +0000
Subject: [PATCH 11/30] Address all test failures.

---
 src/main/aerospike.c                     |  3 ++-
 test/new_tests/as_errors.py              |  2 ++
 test/new_tests/test_exception_subcode.py | 14 ++++++++------
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/main/aerospike.c b/src/main/aerospike.c
index 612a5cae83..7652e3d4ed 100644
--- a/src/main/aerospike.c
+++ b/src/main/aerospike.c
@@ -704,7 +704,8 @@ DEFINE_SET_OF_VALID_KEYS(client_config_tls, "enable", "cafile", "capath",
 
 #define BASE_POLICY_KEYS                                                       \
     "total_timeout", "socket_timeout", "max_retries", "sleep_between_retries", \
-        "compress", "txn", "expressions", "connect_timeout", "timeout_delay"
+        "compress", "txn", "expressions", "connect_timeout", "timeout_delay",  \
+        "error_detail_verbosity"
 
 DEFINE_SET_OF_VALID_KEYS(apply_policy, BASE_POLICY_KEYS, "key", "replica",
                          "commit_level", "durable_delete", "ttl",
diff --git a/test/new_tests/as_errors.py b/test/new_tests/as_errors.py
index c12574049e..5eadffd67e 100644
--- a/test/new_tests/as_errors.py
+++ b/test/new_tests/as_errors.py
@@ -214,6 +214,8 @@
 
 AEROSPIKE_ERR_FAIL_ELEMENT_EXISTS = 24
 
+AEROSPIKE_ERR_OP_NOT_APPLICABLE = 26
+
 AEROSPIKE_FILTERED_OUT = 27
 
 #
diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
index a89e81db2b..afa70ec448 100644
--- a/test/new_tests/test_exception_subcode.py
+++ b/test/new_tests/test_exception_subcode.py
@@ -15,7 +15,8 @@
 
 class TestExceptionSubcode:
     # TODO: need to reuse fixture in conftest.py using indirect params to set num of records
-    def setup(self):
+    @pytest.fixture(autouse=True)
+    def setup(self, as_connection):
         self.as_connection.put(KEY, bins={BIN_NAME: []})
         yield
         self.as_connection.remove(KEY)
@@ -30,18 +31,19 @@ def setup(self):
         ]
     )
     def test_minimum_error_verbosity(self, policy: dict):
-        with pytest.raises(e.InvalidRequest) as excinfo:
+        with pytest.raises(e.OpNotApplicable) as excinfo:
             self.as_connection.operate(KEYS[0], OPS, policy=policy)
 
         # Make sure there's no regression with the parent error code
-        assert excinfo.value.code == as_errors.AEROSPIKE_ERR_REQUEST_INVALID
-        if policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0:
+        assert excinfo.value.code == as_errors.AEROSPIKE_ERR_OP_NOT_APPLICABLE
+        err_verbosity_is_zero = ERROR_DETAIL_VERBOSITY_SETTING not in policy or policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0
+        if err_verbosity_is_zero:
             assert excinfo.value.subcode == 0
         else:
             assert excinfo.value.subcode > 0
 
         SUBCODE_IN_MESSAGE = "subcode="
-        if policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0:
+        if err_verbosity_is_zero:
             assert SUBCODE_IN_MESSAGE not in excinfo.value.msg
         elif policy[ERROR_DETAIL_VERBOSITY_SETTING] == 1:
             # Make sure there's no regression with the server error message
@@ -49,7 +51,7 @@ def test_minimum_error_verbosity(self, policy: dict):
             assert SUBCODE_IN_MESSAGE in excinfo.value.msg
         else:
             # There should be a message before the subcode
-            SUBCODE_IN_QUOTES = "({})".format(SUBCODE_IN_MESSAGE)
+            SUBCODE_IN_QUOTES = "({}".format(SUBCODE_IN_MESSAGE)
             assert SUBCODE_IN_QUOTES in excinfo.value.msg
 
     def test_invalid_verbosity(self):

From 4fb264fd8234a535ba765c781207b87f5fd1a451 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 12:17:52 -0700
Subject: [PATCH 12/30] Move subcode attribute to be last since it's the last
 element in the tuple of exception args.

---
 doc/exception.rst | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/doc/exception.rst b/doc/exception.rst
index 7725705cba..e0055c295b 100644
--- a/doc/exception.rst
+++ b/doc/exception.rst
@@ -40,13 +40,6 @@ Base Class
 
         The associated status code.
 
-    .. py:attribute:: subcode
-
-        Server error detail subcode. When ``error_detail_verbosity`` is greater than or equal to ``1`` on the command's
-        base policy and the server returns structured error details, this field contains the numeric subcode.
-
-        Set to ``0`` when no subcode was returned.
-
     .. py:attribute:: msg
 
         The human-readable error message.
@@ -63,6 +56,13 @@ Base Class
 
         ``True`` if it is possible that the command succeeded. See :ref:`indoubt`.
 
+    .. py:attribute:: subcode
+
+        Server error detail subcode. When ``error_detail_verbosity`` is greater than or equal to ``1`` on the command's
+        base policy and the server returns structured error details, this field contains the numeric subcode.
+
+        Set to ``0`` when no subcode was returned.
+
     In addition to accessing these attributes by their names, \
     they can also be checked by calling ``exc.args[i]``, where ``exc`` is the exception object and \
     ``i`` is the index of the attribute in the order they appear above. \

From 81eeeaab9e3464705e1deba6e769e16a689699f3 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 12:26:42 -0700
Subject: [PATCH 13/30] Have tests expect the returned error subcode to be zero
 for unsupported server versions. This is to make sure undefined behavior
 doesn't happen in the client (e.g uninitialized reads)

---
 test/new_tests/test_exception_subcode.py | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
index afa70ec448..738ccba623 100644
--- a/test/new_tests/test_exception_subcode.py
+++ b/test/new_tests/test_exception_subcode.py
@@ -3,6 +3,7 @@
 import aerospike
 from aerospike import exception as e
 from aerospike_helpers.operations import list_operations as list_ops
+from .test_base_class import TestBaseClass
 from . import as_errors
 
 
@@ -36,7 +37,16 @@ def test_minimum_error_verbosity(self, policy: dict):
 
         # Make sure there's no regression with the parent error code
         assert excinfo.value.code == as_errors.AEROSPIKE_ERR_OP_NOT_APPLICABLE
-        err_verbosity_is_zero = ERROR_DETAIL_VERBOSITY_SETTING not in policy or policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0
+
+        err_verbosity_is_zero = (
+            ERROR_DETAIL_VERBOSITY_SETTING not in policy
+            or
+            policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0
+            or
+            # If running against a unsupported version, we expect subcode to always return 0
+            # (and no undefined behavior)
+            (TestBaseClass.major_ver, TestBaseClass.minor_ver, TestBaseClass.patch_ver) < (8, 1, 3)
+        )
         if err_verbosity_is_zero:
             assert excinfo.value.subcode == 0
         else:

From bddc408da38ca2bddc8b1401e2c4eb7991ac91c4 Mon Sep 17 00:00:00 2001
From: juliannguyen4 <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 21:41:58 +0000
Subject: [PATCH 14/30] Now that Nate's feature branch for string ops is
 rebased onto master, the server now has the correct 8.1.3 version.

---
 test/new_tests/conftest.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/new_tests/conftest.py b/test/new_tests/conftest.py
index 24106e01b5..bbfaa2e3c0 100644
--- a/test/new_tests/conftest.py
+++ b/test/new_tests/conftest.py
@@ -326,7 +326,7 @@ def expect_earlier_than_server_version_to_fail(as_connection, request):
 expect_server_version_earlier_than_8_1_3_to_fail = pytest.mark.parametrize(
     "expect_earlier_than_server_version_to_fail",
     [
-        (8, 1, 2)
+        (8, 1, 3)
     ],
     indirect=True
 )

From 6cdcb85403a207aa0a03a454c62949e5c9d533f2 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Tue, 16 Jun 2026 14:50:16 -0700
Subject: [PATCH 15/30] Address failing spellcheck

---
 doc/spelling_wordlist.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/spelling_wordlist.txt b/doc/spelling_wordlist.txt
index 48c700fbad..f5c69a015d 100644
--- a/doc/spelling_wordlist.txt
+++ b/doc/spelling_wordlist.txt
@@ -103,3 +103,4 @@ lowercases
 lowercased
 msgpack
 precomposed
+subcode

From ae388db250106d69a363dec0d39ae50cfb709542 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 17 Jun 2026 08:01:14 -0700
Subject: [PATCH 16/30] Refactor some deprecation message work. Deprecate
 operations.prepend() and append() only when strings are passed as arguments
 in favor of the string ops version.

---
 src/include/client.h      |  3 +++
 src/main/client/operate.c | 26 ++++++++++++++++++++++++++
 src/main/conversions.c    | 13 ++++++-------
 3 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/src/include/client.h b/src/include/client.h
index d4aecf92a6..d5498d418c 100644
--- a/src/include/client.h
+++ b/src/include/client.h
@@ -591,3 +591,6 @@ PyObject *AerospikeClient_Abort(AerospikeClient *self, PyObject *args,
     "Operations and bin names are mutually exclusive."                         \
     "In the next major client release, when this %s object is executed, a "    \
     "ParamError will be raised."
+
+#define DEPRECATION_MESSAGE_TEMPLATE                                           \
+    "%s is deprecated and will be removed in the next client major release"
diff --git a/src/main/client/operate.c b/src/main/client/operate.c
index c95e338de8..633f791198 100644
--- a/src/main/client/operate.c
+++ b/src/main/client/operate.c
@@ -310,6 +310,10 @@ bool opRequiresKey(int op)
             op == OP_MAP_GET_BY_KEY_RANGE);
 }
 
+#define DEPRECATED_PREPEND_NAME                                                \
+    "aerospike_helpers.operations.operations.prepend"
+#define DEPRECATED_APPEND_NAME "aerospike_helpers.operations.operations.append"
+
 as_status add_op(AerospikeClient *self, as_error *err,
                  PyObject *py_operation_dict, as_vector *unicodeStrVector,
                  as_static_pool *static_pool, as_operations *ops, long *op,
@@ -615,6 +619,17 @@ as_status add_op(AerospikeClient *self, as_error *err,
     }
     case AS_OPERATOR_APPEND:
         if (PyUnicode_Check(py_value)) {
+            int retval = PyErr_WarnFormat(PyExc_DeprecationWarning, STACK_LEVEL,
+                                          DEPRECATION_MESSAGE_TEMPLATE,
+                                          DEPRECATED_APPEND_NAME);
+            if (retval == -1) {
+                // This handles the codepath where warnings are converted into errors from pytest/python cli
+                // TODO: this does NOT handle the codepath where the warning mechanism itself fails
+                return as_error_update(err, AEROSPIKE_ERR,
+                                       DEPRECATION_MESSAGE_TEMPLATE,
+                                       DEPRECATED_APPEND_NAME);
+            }
+
             py_ustr1 = PyUnicode_AsUTF8String(py_value);
             val = strdup(PyBytes_AsString(py_ustr1));
             as_operations_add_append_str(ops, bin, val);
@@ -648,6 +663,17 @@ as_status add_op(AerospikeClient *self, as_error *err,
         break;
     case AS_OPERATOR_PREPEND:
         if (PyUnicode_Check(py_value)) {
+            int retval = PyErr_WarnFormat(PyExc_DeprecationWarning, STACK_LEVEL,
+                                          DEPRECATION_MESSAGE_TEMPLATE,
+                                          DEPRECATED_PREPEND_NAME);
+            if (retval == -1) {
+                // This handles the codepath where warnings are converted into errors from pytest/python cli
+                // TODO: this does NOT handle the codepath where the warning mechanism itself fails
+                return as_error_update(err, AEROSPIKE_ERR,
+                                       DEPRECATION_MESSAGE_TEMPLATE,
+                                       DEPRECATED_PREPEND_NAME);
+            }
+
             py_ustr1 = PyUnicode_AsUTF8String(py_value);
             val = strdup(PyBytes_AsString(py_ustr1));
             as_operations_add_prepend_str(ops, bin, val);
diff --git a/src/main/conversions.c b/src/main/conversions.c
index 1f8e3e0339..addd219524 100644
--- a/src/main/conversions.c
+++ b/src/main/conversions.c
@@ -2379,9 +2379,7 @@ void initialize_bin_for_strictypes(AerospikeClient *self, as_error *err,
     strcpy(binop_bin->name, bin);
 }
 
-#define META_TTL_DEPRECATION_MESSAGE                                           \
-    "meta[\"ttl\"] is deprecated and will be removed in "                      \
-    "the next client major release."
+#define META_TTL_FOR_DEPRECATION_WARNING "meta[\"ttl\"]"
 
 /**
  *******************************************************************************************************
@@ -2421,14 +2419,15 @@ as_status check_and_set_meta(PyObject *py_meta, uint32_t *ttl_ref,
         uint32_t ttl = 0;
         uint16_t gen = 0;
         if (py_ttl) {
-            int retval =
-                PyErr_WarnEx(PyExc_DeprecationWarning,
-                             META_TTL_DEPRECATION_MESSAGE, STACK_LEVEL);
+            int retval = PyErr_WarnFormat(PyExc_DeprecationWarning, STACK_LEVEL,
+                                          DEPRECATION_MESSAGE_TEMPLATE,
+                                          META_TTL_FOR_DEPRECATION_WARNING);
             if (retval == -1) {
                 // This handles the codepath where warnings are converted into errors from pytest/python cli
                 // TODO: this does NOT handle the codepath where the warning mechanism itself fails
                 return as_error_update(err, AEROSPIKE_ERR,
-                                       META_TTL_DEPRECATION_MESSAGE);
+                                       DEPRECATION_MESSAGE_TEMPLATE,
+                                       META_TTL_FOR_DEPRECATION_WARNING);
             }
 
             if (PyLong_Check(py_ttl)) {

From 093731e1b33b106a99719811bb91e180a0d23293 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 17 Jun 2026 09:11:26 -0700
Subject: [PATCH 17/30] Revert "Refactor some deprecation message work.
 Deprecate operations.prepend() and append() only when strings are passed as
 arguments in favor of the string ops version."

This reverts commit ae388db250106d69a363dec0d39ae50cfb709542.
---
 src/include/client.h      |  3 ---
 src/main/client/operate.c | 26 --------------------------
 src/main/conversions.c    | 13 +++++++------
 3 files changed, 7 insertions(+), 35 deletions(-)

diff --git a/src/include/client.h b/src/include/client.h
index d5498d418c..d4aecf92a6 100644
--- a/src/include/client.h
+++ b/src/include/client.h
@@ -591,6 +591,3 @@ PyObject *AerospikeClient_Abort(AerospikeClient *self, PyObject *args,
     "Operations and bin names are mutually exclusive."                         \
     "In the next major client release, when this %s object is executed, a "    \
     "ParamError will be raised."
-
-#define DEPRECATION_MESSAGE_TEMPLATE                                           \
-    "%s is deprecated and will be removed in the next client major release"
diff --git a/src/main/client/operate.c b/src/main/client/operate.c
index 633f791198..c95e338de8 100644
--- a/src/main/client/operate.c
+++ b/src/main/client/operate.c
@@ -310,10 +310,6 @@ bool opRequiresKey(int op)
             op == OP_MAP_GET_BY_KEY_RANGE);
 }
 
-#define DEPRECATED_PREPEND_NAME                                                \
-    "aerospike_helpers.operations.operations.prepend"
-#define DEPRECATED_APPEND_NAME "aerospike_helpers.operations.operations.append"
-
 as_status add_op(AerospikeClient *self, as_error *err,
                  PyObject *py_operation_dict, as_vector *unicodeStrVector,
                  as_static_pool *static_pool, as_operations *ops, long *op,
@@ -619,17 +615,6 @@ as_status add_op(AerospikeClient *self, as_error *err,
     }
     case AS_OPERATOR_APPEND:
         if (PyUnicode_Check(py_value)) {
-            int retval = PyErr_WarnFormat(PyExc_DeprecationWarning, STACK_LEVEL,
-                                          DEPRECATION_MESSAGE_TEMPLATE,
-                                          DEPRECATED_APPEND_NAME);
-            if (retval == -1) {
-                // This handles the codepath where warnings are converted into errors from pytest/python cli
-                // TODO: this does NOT handle the codepath where the warning mechanism itself fails
-                return as_error_update(err, AEROSPIKE_ERR,
-                                       DEPRECATION_MESSAGE_TEMPLATE,
-                                       DEPRECATED_APPEND_NAME);
-            }
-
             py_ustr1 = PyUnicode_AsUTF8String(py_value);
             val = strdup(PyBytes_AsString(py_ustr1));
             as_operations_add_append_str(ops, bin, val);
@@ -663,17 +648,6 @@ as_status add_op(AerospikeClient *self, as_error *err,
         break;
     case AS_OPERATOR_PREPEND:
         if (PyUnicode_Check(py_value)) {
-            int retval = PyErr_WarnFormat(PyExc_DeprecationWarning, STACK_LEVEL,
-                                          DEPRECATION_MESSAGE_TEMPLATE,
-                                          DEPRECATED_PREPEND_NAME);
-            if (retval == -1) {
-                // This handles the codepath where warnings are converted into errors from pytest/python cli
-                // TODO: this does NOT handle the codepath where the warning mechanism itself fails
-                return as_error_update(err, AEROSPIKE_ERR,
-                                       DEPRECATION_MESSAGE_TEMPLATE,
-                                       DEPRECATED_PREPEND_NAME);
-            }
-
             py_ustr1 = PyUnicode_AsUTF8String(py_value);
             val = strdup(PyBytes_AsString(py_ustr1));
             as_operations_add_prepend_str(ops, bin, val);
diff --git a/src/main/conversions.c b/src/main/conversions.c
index addd219524..1f8e3e0339 100644
--- a/src/main/conversions.c
+++ b/src/main/conversions.c
@@ -2379,7 +2379,9 @@ void initialize_bin_for_strictypes(AerospikeClient *self, as_error *err,
     strcpy(binop_bin->name, bin);
 }
 
-#define META_TTL_FOR_DEPRECATION_WARNING "meta[\"ttl\"]"
+#define META_TTL_DEPRECATION_MESSAGE                                           \
+    "meta[\"ttl\"] is deprecated and will be removed in "                      \
+    "the next client major release."
 
 /**
  *******************************************************************************************************
@@ -2419,15 +2421,14 @@ as_status check_and_set_meta(PyObject *py_meta, uint32_t *ttl_ref,
         uint32_t ttl = 0;
         uint16_t gen = 0;
         if (py_ttl) {
-            int retval = PyErr_WarnFormat(PyExc_DeprecationWarning, STACK_LEVEL,
-                                          DEPRECATION_MESSAGE_TEMPLATE,
-                                          META_TTL_FOR_DEPRECATION_WARNING);
+            int retval =
+                PyErr_WarnEx(PyExc_DeprecationWarning,
+                             META_TTL_DEPRECATION_MESSAGE, STACK_LEVEL);
             if (retval == -1) {
                 // This handles the codepath where warnings are converted into errors from pytest/python cli
                 // TODO: this does NOT handle the codepath where the warning mechanism itself fails
                 return as_error_update(err, AEROSPIKE_ERR,
-                                       DEPRECATION_MESSAGE_TEMPLATE,
-                                       META_TTL_FOR_DEPRECATION_WARNING);
+                                       META_TTL_DEPRECATION_MESSAGE);
             }
 
             if (PyLong_Check(py_ttl)) {

From 2011bc31c081604f5b78b961be0289bbcfc1b510 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 17 Jun 2026 09:17:39 -0700
Subject: [PATCH 18/30] Revert adding subcode to AerospikeError.args tuple to
 avoid an API breaking change per product team's request.

---
 src/main/conversions.c |  2 --
 src/main/exception.c   | 20 +++++++++++++++++---
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/src/main/conversions.c b/src/main/conversions.c
index 1f8e3e0339..e4948ab228 100644
--- a/src/main/conversions.c
+++ b/src/main/conversions.c
@@ -60,7 +60,6 @@ enum {
     PY_EXCEPTION_FILE,
     PY_EXCEPTION_LINE,
     AS_PY_EXCEPTION_IN_DOUBT,
-    PY_EXCEPTION_SUBCODE,
     EXCEPTION_TUPLE_MEMBER_COUNT
 };
 
@@ -2299,7 +2298,6 @@ void error_to_pyobject(const as_error *err, PyObject **obj)
     PyTuple_SetItem(py_err, PY_EXCEPTION_FILE, py_file);
     PyTuple_SetItem(py_err, PY_EXCEPTION_LINE, py_line);
     PyTuple_SetItem(py_err, AS_PY_EXCEPTION_IN_DOUBT, py_in_doubt);
-    PyTuple_SetItem(py_err, PY_EXCEPTION_SUBCODE, py_subcode);
     *obj = py_err;
 }
 
diff --git a/src/main/exception.c b/src/main/exception.c
index e1db02a537..dbdfd6df24 100644
--- a/src/main/exception.c
+++ b/src/main/exception.c
@@ -470,9 +470,12 @@ void raise_exception_base(as_error *err, PyObject *py_as_key, PyObject *py_bin,
         goto CHAIN_PREV_EXC_AND_RETURN;
     }
 
-    for (unsigned long i = 0;
-         i < sizeof(aerospike_err_attrs) / sizeof(aerospike_err_attrs[0]) - 1;
-         i++) {
+    Py_ssize_t tuple_size = PyTuple_Size(py_err_tuple);
+    if (tuple_size == -1) {
+        goto CHAIN_PREV_EXC_AND_RETURN;
+    }
+
+    for (Py_ssize_t i = 0; i < tuple_size; i++) {
         // Here, we are assuming the number of attrs is the same as the number of tuple members
         PyObject *py_arg = PyTuple_GetItem(py_err_tuple, i);
         if (py_arg == NULL) {
@@ -485,6 +488,17 @@ void raise_exception_base(as_error *err, PyObject *py_as_key, PyObject *py_bin,
         }
     }
 
+    PyObject *py_subcode = PyLong_FromUInt32(err->subcode);
+    if (!py_subcode) {
+        goto CHAIN_PREV_EXC_AND_RETURN;
+    }
+
+    int retval = PyObject_SetAttrString(
+        py_exc_class, aerospike_err_attrs[tuple_size], py_subcode);
+    if (retval == -1) {
+        goto CHAIN_PREV_EXC_AND_RETURN;
+    }
+
     // Raise exception
     PyErr_SetObject(py_exc_class, py_err_tuple);
     Py_DECREF(py_err_tuple);

From 9ca94b49d3854e0a41f8ae047ef7fe8e04823cba Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 17 Jun 2026 09:22:03 -0700
Subject: [PATCH 19/30] Rm dead code.

---
 src/main/conversions.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/main/conversions.c b/src/main/conversions.c
index e4948ab228..5eea7e2e7b 100644
--- a/src/main/conversions.c
+++ b/src/main/conversions.c
@@ -2290,8 +2290,6 @@ void error_to_pyobject(const as_error *err, PyObject **obj)
     PyObject *py_in_doubt = err->in_doubt ? Py_True : Py_False;
     Py_INCREF(py_in_doubt);
 
-    PyObject *py_subcode = PyLong_FromLong(err->subcode);
-
     PyObject *py_err = PyTuple_New(EXCEPTION_TUPLE_MEMBER_COUNT);
     PyTuple_SetItem(py_err, PY_EXCEPTION_CODE, py_code);
     PyTuple_SetItem(py_err, PY_EXCEPTION_MSG, py_message);

From d8ec58bf5ddab62c4c27b7eb86ac6930d9f7251a Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 17 Jun 2026 12:37:08 -0700
Subject: [PATCH 20/30] Update C client to include the latest revisions to the
 string op API.

---
 aerospike-client-c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/aerospike-client-c b/aerospike-client-c
index ae201bf16c..e84494241b 160000
--- a/aerospike-client-c
+++ b/aerospike-client-c
@@ -1 +1 @@
-Subproject commit ae201bf16c02977d16a9bc90931184fe6a40cf00
+Subproject commit e84494241be7c4e9a0c6bd8951f277caf71d96bc

From f56a4e202e83cdc1b120ec553f45431fdf788dc6 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 17 Jun 2026 13:22:14 -0700
Subject: [PATCH 21/30] Revert "Update C client to include the latest revisions
 to the string op API."

This reverts commit d8ec58bf5ddab62c4c27b7eb86ac6930d9f7251a.
---
 aerospike-client-c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/aerospike-client-c b/aerospike-client-c
index e84494241b..ae201bf16c 160000
--- a/aerospike-client-c
+++ b/aerospike-client-c
@@ -1 +1 @@
-Subproject commit e84494241be7c4e9a0c6bd8951f277caf71d96bc
+Subproject commit ae201bf16c02977d16a9bc90931184fe6a40cf00

From 6e03d250702766f3a1e641f0cf652f70f2959e0f Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Wed, 17 Jun 2026 19:12:48 -0700
Subject: [PATCH 22/30] Fix crash

---
 src/main/client/list_and_string_operate.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/main/client/list_and_string_operate.c b/src/main/client/list_and_string_operate.c
index 06fb59069b..13e8f0fd33 100644
--- a/src/main/client/list_and_string_operate.c
+++ b/src/main/client/list_and_string_operate.c
@@ -344,7 +344,6 @@ as_status add_list_or_string_op(AerospikeClient *self, as_error *err,
     case OP_STRING_REGEX_COMPARE:
     case OP_STRING_INSERT:
     case OP_STRING_OVERWRITE:
-    case OP_STRING_CONCAT:
     case OP_STRING_REPLACE:
     case OP_STRING_REPLACE_ALL:
     case OP_STRING_PAD_START:

From 31441f92494caf58e1b1b7e47fe1636bdc171ab1 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Thu, 18 Jun 2026 08:44:44 -0700
Subject: [PATCH 23/30] Address test failure.

---
 test/new_tests/test_expressions_string.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/new_tests/test_expressions_string.py b/test/new_tests/test_expressions_string.py
index bc91a2648f..0e3f3f38c7 100644
--- a/test/new_tests/test_expressions_string.py
+++ b/test/new_tests/test_expressions_string.py
@@ -26,8 +26,8 @@ def setup(self, request, as_connection, expect_earlier_than_server_version_to_fa
         "expr, expected_result",
         [
             (str_expr.StrLen(bin=STR_BIN_NAME), len(BINS[STR_BIN_NAME])),
-            (str_expr.SubStr(start=START_IDX, end=None, bin=STR_BIN_NAME), BINS[STR_BIN_NAME][START_IDX:]),
-            (str_expr.SubStr(start=START_IDX, end=START_IDX + 2, bin=STR_BIN_NAME), BINS[STR_BIN_NAME][START_IDX:(START_IDX + 2)]),
+            (str_expr.SubStr(start=START_IDX, bin=STR_BIN_NAME), BINS[STR_BIN_NAME][START_IDX:]),
+            (str_expr.SubStrRange(start=START_IDX, end=START_IDX + 2, bin=STR_BIN_NAME), BINS[STR_BIN_NAME][START_IDX:(START_IDX + 2)]),
             (str_expr.CharAt(index=START_IDX, bin=STR_BIN_NAME), BINS[STR_BIN_NAME][START_IDX]),
             (str_expr.CharAt(index=-1, bin=STR_BIN_NAME), BINS[STR_BIN_NAME][-1]),
             (str_expr.Find(needle=NEEDLE, occurrence=1, bin=STR_BIN_NAME), BINS[STR_BIN_NAME].find(NEEDLE)),

From 3ea35faf7575f7210dadeba4bed75acc0a1543f6 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 22 Jun 2026 13:41:13 -0700
Subject: [PATCH 24/30] Address stubtest failure.

---
 aerospike-stubs/exception.pyi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/aerospike-stubs/exception.pyi b/aerospike-stubs/exception.pyi
index e5a3b1fc52..48021b69c8 100644
--- a/aerospike-stubs/exception.pyi
+++ b/aerospike-stubs/exception.pyi
@@ -3,7 +3,7 @@ from typing import Union
 class AerospikeError(Exception):
     # When attributes are first assigned to exception class, they have an initial value of None
     code: Union[int, None]
-    subcode: int
+    subcode: Union[int, None]
     msg: Union[str, None]
     file: Union[str, None]
     line: Union[int, None]

From 72d42b65ff785c0ac02d283709a227af4f85f8b0 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 22 Jun 2026 14:27:10 -0700
Subject: [PATCH 25/30] Improve helper function naming. Clear up why subcode
 attribute name is at index tuple_size

---
 src/include/conversions.h | 2 +-
 src/main/conversions.c    | 2 +-
 src/main/exception.c      | 3 ++-
 src/main/query/where.c    | 2 +-
 4 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/include/conversions.h b/src/include/conversions.h
index b891bcffe6..e33f1cdc88 100644
--- a/src/include/conversions.h
+++ b/src/include/conversions.h
@@ -127,7 +127,7 @@ as_status metadata_to_pyobject(as_error *err, const as_record *rec,
 as_status bins_to_pyobject(AerospikeClient *self, as_error *err,
                            const as_record *rec, PyObject **obj);
 
-void error_to_pyobject(const as_error *err, PyObject **obj);
+void create_py_tuple_from_as_error(const as_error *err, PyObject **obj);
 
 as_status as_privilege_to_pyobject(as_error *err, as_privilege privileges[],
                                    PyObject *py_as_privilege,
diff --git a/src/main/conversions.c b/src/main/conversions.c
index 3d026b76f3..6e6e06ca99 100644
--- a/src/main/conversions.c
+++ b/src/main/conversions.c
@@ -2263,7 +2263,7 @@ as_status metadata_to_pyobject(as_error *err, const as_record *rec,
     return err->code;
 }
 
-void error_to_pyobject(const as_error *err, PyObject **obj)
+void create_py_tuple_from_as_error(const as_error *err, PyObject **obj)
 {
     PyObject *py_file = NULL;
     if (err->file) {
diff --git a/src/main/exception.c b/src/main/exception.c
index dbdfd6df24..16b30dbdab 100644
--- a/src/main/exception.c
+++ b/src/main/exception.c
@@ -465,7 +465,7 @@ void raise_exception_base(as_error *err, PyObject *py_as_key, PyObject *py_bin,
 
     // Convert C error to Python exception
     PyObject *py_err_tuple = NULL;
-    error_to_pyobject(err, &py_err_tuple);
+    create_py_tuple_from_as_error(err, &py_err_tuple);
     if (!py_err_tuple) {
         goto CHAIN_PREV_EXC_AND_RETURN;
     }
@@ -493,6 +493,7 @@ void raise_exception_base(as_error *err, PyObject *py_as_key, PyObject *py_bin,
         goto CHAIN_PREV_EXC_AND_RETURN;
     }
 
+    // Subcode is not included as last element in tuple
     int retval = PyObject_SetAttrString(
         py_exc_class, aerospike_err_attrs[tuple_size], py_subcode);
     if (retval == -1) {
diff --git a/src/main/query/where.c b/src/main/query/where.c
index f9eb0e37d5..dcd50de34f 100644
--- a/src/main/query/where.c
+++ b/src/main/query/where.c
@@ -281,7 +281,7 @@ static int AerospikeQuery_Where_Add(AerospikeQuery *self, PyObject *py_ctx,
         // If it ain't supported, raise and error
         as_error_update(&err, AEROSPIKE_ERR_PARAM, "unknown predicate type");
         PyObject *py_err = NULL;
-        error_to_pyobject(&err, &py_err);
+        create_py_tuple_from_as_error(&err, &py_err);
         PyErr_SetObject(PyExc_Exception, py_err);
         goto CLEANUP_VALUES_ON_ERROR;
     }

From 25806afcdda973a8451a3b4578e08bb0acd14069 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 22 Jun 2026 14:34:30 -0700
Subject: [PATCH 26/30] Address misleading test case name.

---
 test/new_tests/test_exception_subcode.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
index 738ccba623..3122665e32 100644
--- a/test/new_tests/test_exception_subcode.py
+++ b/test/new_tests/test_exception_subcode.py
@@ -31,7 +31,7 @@ def setup(self, as_connection):
             {ERROR_DETAIL_VERBOSITY_SETTING: 2},
         ]
     )
-    def test_minimum_error_verbosity(self, policy: dict):
+    def test_error_verbosity_levels(self, policy: dict):
         with pytest.raises(e.OpNotApplicable) as excinfo:
             self.as_connection.operate(KEYS[0], OPS, policy=policy)
 

From fa3359aadeefaabca3d5919d635d51b6d494dffa Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 22 Jun 2026 14:39:58 -0700
Subject: [PATCH 27/30] Rm confusing comment. Improve var naming in tests.

---
 test/new_tests/test_exception_subcode.py | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
index 3122665e32..e3545709b7 100644
--- a/test/new_tests/test_exception_subcode.py
+++ b/test/new_tests/test_exception_subcode.py
@@ -38,7 +38,7 @@ def test_error_verbosity_levels(self, policy: dict):
         # Make sure there's no regression with the parent error code
         assert excinfo.value.code == as_errors.AEROSPIKE_ERR_OP_NOT_APPLICABLE
 
-        err_verbosity_is_zero = (
+        subcode_should_be_zero = (
             ERROR_DETAIL_VERBOSITY_SETTING not in policy
             or
             policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0
@@ -47,21 +47,19 @@ def test_error_verbosity_levels(self, policy: dict):
             # (and no undefined behavior)
             (TestBaseClass.major_ver, TestBaseClass.minor_ver, TestBaseClass.patch_ver) < (8, 1, 3)
         )
-        if err_verbosity_is_zero:
+        if subcode_should_be_zero:
             assert excinfo.value.subcode == 0
         else:
             assert excinfo.value.subcode > 0
 
-        SUBCODE_IN_MESSAGE = "subcode="
-        if err_verbosity_is_zero:
-            assert SUBCODE_IN_MESSAGE not in excinfo.value.msg
+        EXPECTED_SUBCODE_IN_MESSAGE = "subcode="
+        if subcode_should_be_zero:
+            assert EXPECTED_SUBCODE_IN_MESSAGE not in excinfo.value.msg
         elif policy[ERROR_DETAIL_VERBOSITY_SETTING] == 1:
-            # Make sure there's no regression with the server error message
-            # with lower verbosity
-            assert SUBCODE_IN_MESSAGE in excinfo.value.msg
+            assert EXPECTED_SUBCODE_IN_MESSAGE in excinfo.value.msg
         else:
             # There should be a message before the subcode
-            SUBCODE_IN_QUOTES = "({}".format(SUBCODE_IN_MESSAGE)
+            SUBCODE_IN_QUOTES = "({}".format(EXPECTED_SUBCODE_IN_MESSAGE)
             assert SUBCODE_IN_QUOTES in excinfo.value.msg
 
     def test_invalid_verbosity(self):

From a1c3203d0fb7ebb773c98c07e1946ada6ffac2b7 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 22 Jun 2026 14:41:04 -0700
Subject: [PATCH 28/30] Make test logic less confusing.

---
 test/new_tests/test_exception_subcode.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
index e3545709b7..82e72e7682 100644
--- a/test/new_tests/test_exception_subcode.py
+++ b/test/new_tests/test_exception_subcode.py
@@ -53,7 +53,7 @@ def test_error_verbosity_levels(self, policy: dict):
             assert excinfo.value.subcode > 0
 
         EXPECTED_SUBCODE_IN_MESSAGE = "subcode="
-        if subcode_should_be_zero:
+        if excinfo.value.subcode == 0:
             assert EXPECTED_SUBCODE_IN_MESSAGE not in excinfo.value.msg
         elif policy[ERROR_DETAIL_VERBOSITY_SETTING] == 1:
             assert EXPECTED_SUBCODE_IN_MESSAGE in excinfo.value.msg

From e5930b7d66862b1a4513708ed94912d155002124 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 22 Jun 2026 15:16:31 -0700
Subject: [PATCH 29/30] Add test cases for client config option to increase
 code coverage.

---
 test/new_tests/test_exception_subcode.py | 28 +++++++++++++++++++-----
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/test/new_tests/test_exception_subcode.py b/test/new_tests/test_exception_subcode.py
index 82e72e7682..132d597f48 100644
--- a/test/new_tests/test_exception_subcode.py
+++ b/test/new_tests/test_exception_subcode.py
@@ -23,7 +23,7 @@ def setup(self, as_connection):
         self.as_connection.remove(KEY)
 
     @pytest.mark.parametrize(
-        "policy",
+        "policy_w_verbosity_setting",
         [
             {},
             {ERROR_DETAIL_VERBOSITY_SETTING: 0},
@@ -31,17 +31,33 @@ def setup(self, as_connection):
             {ERROR_DETAIL_VERBOSITY_SETTING: 2},
         ]
     )
-    def test_error_verbosity_levels(self, policy: dict):
+    @pytest.mark.parametrize(
+        "set_in_client_config",
+        [False, True]
+    )
+    def test_error_verbosity_levels(self, policy_w_verbosity_setting: dict, set_in_client_config: bool):
+        if set_in_client_config:
+            config = {
+                "policies": {
+                    "operate": policy_w_verbosity_setting
+                }
+            }
+            self.as_connection = TestBaseClass.get_new_connection(config)
+
         with pytest.raises(e.OpNotApplicable) as excinfo:
-            self.as_connection.operate(KEYS[0], OPS, policy=policy)
+            cmd_policy = {}
+            if not set_in_client_config:
+                cmd_policy |= policy_w_verbosity_setting
+
+            self.as_connection.operate(KEYS[0], OPS, policy=cmd_policy)
 
         # Make sure there's no regression with the parent error code
         assert excinfo.value.code == as_errors.AEROSPIKE_ERR_OP_NOT_APPLICABLE
 
         subcode_should_be_zero = (
-            ERROR_DETAIL_VERBOSITY_SETTING not in policy
+            ERROR_DETAIL_VERBOSITY_SETTING not in policy_w_verbosity_setting
             or
-            policy[ERROR_DETAIL_VERBOSITY_SETTING] == 0
+            policy_w_verbosity_setting[ERROR_DETAIL_VERBOSITY_SETTING] == 0
             or
             # If running against a unsupported version, we expect subcode to always return 0
             # (and no undefined behavior)
@@ -55,7 +71,7 @@ def test_error_verbosity_levels(self, policy: dict):
         EXPECTED_SUBCODE_IN_MESSAGE = "subcode="
         if excinfo.value.subcode == 0:
             assert EXPECTED_SUBCODE_IN_MESSAGE not in excinfo.value.msg
-        elif policy[ERROR_DETAIL_VERBOSITY_SETTING] == 1:
+        elif policy_w_verbosity_setting[ERROR_DETAIL_VERBOSITY_SETTING] == 1:
             assert EXPECTED_SUBCODE_IN_MESSAGE in excinfo.value.msg
         else:
             # There should be a message before the subcode

From c8703199517f3cf98fb5aaf55c368625f06f1023 Mon Sep 17 00:00:00 2001
From: Julian Nguyen <109386615+juliannguyen4@users.noreply.github.com>
Date: Mon, 22 Jun 2026 15:22:25 -0700
Subject: [PATCH 30/30] Make TestBaseClass.get_new_connection() set the server
 version digits as integers to be consistent with the as_connection fixture.

---
 test/new_tests/test_base_class.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/test/new_tests/test_base_class.py b/test/new_tests/test_base_class.py
index 6256e32dd5..0519ba5705 100644
--- a/test/new_tests/test_base_class.py
+++ b/test/new_tests/test_base_class.py
@@ -178,9 +178,9 @@ def get_new_connection(add_config=None):
                 if res is not None:
                     break
             res = res.split(".")
-            TestBaseClass.major_ver = res[0]
-            TestBaseClass.minor_ver = res[1]
-            TestBaseClass.minor_ver = res[2]
+            TestBaseClass.major_ver = int(res[0])
+            TestBaseClass.minor_ver = int(res[1])
+            TestBaseClass.minor_ver = int(res[2])
             # print("major_ver:", TestBaseClass.major_ver, "minor_ver:", TestBaseClass.minor_ver)
 
         return client