diff --git a/tests/memory/long_term_memory_backends/test_redis_ltm_client.py b/tests/memory/long_term_memory_backends/test_redis_ltm_client.py
new file mode 100644
index 000000000..5509ffa5b
--- /dev/null
+++ b/tests/memory/long_term_memory_backends/test_redis_ltm_client.py
@@ -0,0 +1,80 @@
+# Copyright (c) 2025 Beijing Volcano Engine Technology Co., Ltd. and/or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pytest
+from llama_index.core.embeddings import MockEmbedding
+
+from veadk.configs.database_configs import RedisConfig
+from veadk.memory.long_term_memory_backends import redis_backend
+from veadk.memory.long_term_memory_backends.redis_backend import RedisLTMBackend
+
+
+@pytest.fixture
+def redis_kwargs(monkeypatch):
+    monkeypatch.setenv("MODEL_EMBEDDING_API_KEY", "test-key")
+    monkeypatch.setattr(
+        redis_backend,
+        "create_embedding_model",
+        lambda **_: MockEmbedding(embed_dim=8),
+    )
+    captured = []
+
+    class _FakeRedis:
+        def __init__(self, **kwargs):
+            captured.append(kwargs)
+
+    class _FakeRedisVectorStore:
+        def __init__(self, schema, redis_client):
+            self.schema = schema
+            self.index_name = schema.index.name
+
+    monkeypatch.setattr(redis_backend, "Redis", _FakeRedis)
+    monkeypatch.setattr(redis_backend, "RedisVectorStore", _FakeRedisVectorStore)
+    monkeypatch.setattr(
+        redis_backend.VectorStoreIndex,
+        "from_vector_store",
+        staticmethod(lambda vector_store, embed_model: None),
+    )
+    return captured
+
+
+def test_redis_client_uses_configured_username(redis_kwargs):
+    config = RedisConfig(
+        host="redis.example", port=6380, username="ltm-user", password="pw", db=2
+    )
+    backend = RedisLTMBackend(index="app", redis_config=config)
+
+    backend._create_vector_index("veadk-ltm/app/u1")
+
+    assert redis_kwargs == [
+        {
+            "host": "redis.example",
+            "port": 6380,
+            "db": 2,
+            "username": "ltm-user",
+            "password": "pw",
+        }
+    ]
+
+
+def test_redis_username_is_read_from_env(redis_kwargs, monkeypatch):
+    monkeypatch.setenv("DATABASE_REDIS_HOST", "redis.example")
+    monkeypatch.setenv("DATABASE_REDIS_USERNAME", "ltm-user")
+    monkeypatch.setenv("DATABASE_REDIS_PASSWORD", "pw")
+    backend = RedisLTMBackend(index="app")
+
+    backend._create_vector_index("veadk-ltm/app/u1")
+
+    assert redis_kwargs[0]["username"] == "ltm-user"
+    assert redis_kwargs[0]["password"] == "pw"
diff --git a/veadk/cli/cli_harness.py b/veadk/cli/cli_harness.py
index e29b1be8e..208c05505 100644
--- a/veadk/cli/cli_harness.py
+++ b/veadk/cli/cli_harness.py
@@ -142,9 +142,10 @@
   # port: 9200
   # username: admin
   # password: ""
-  # -- redis --       env DATABASE_REDIS_*     flags: --long-term-memory-host / -port / -password / -db
+  # -- redis --       env DATABASE_REDIS_*     flags: --long-term-memory-host / -port / -username / -password / -db
   # host: 1.2.3.4
   # port: 6379
+  # username: default
   # password: ""
   # db: 0
   # -- mem0 --        env DATABASE_MEM0_*      flags: --long-term-memory-api-key / -api-key-id / -project-id / -base-url
diff --git a/veadk/memory/long_term_memory_backends/redis_backend.py b/veadk/memory/long_term_memory_backends/redis_backend.py
index c199f3c6c..bf0f17335 100644
--- a/veadk/memory/long_term_memory_backends/redis_backend.py
+++ b/veadk/memory/long_term_memory_backends/redis_backend.py
@@ -73,6 +73,7 @@ def _create_vector_index(self, index: str) -> VectorStoreIndex:
             host=self.redis_config.host,
             port=self.redis_config.port,
             db=self.redis_config.db,
+            username=self.redis_config.username,
             password=self.redis_config.password,
         )