diff --git a/backend/tests/AGENTS.md b/backend/tests/AGENTS.md
index 02653e71ae..e98283a7a4 100644
--- a/backend/tests/AGENTS.md
+++ b/backend/tests/AGENTS.md
@@ -363,6 +363,14 @@ setup, after the autouse fixtures initialize runtime, to avoid the package cycle
 
 `test_managed_provider_presets.py` covers encrypted compatibility, auto IDs, key switching, snapshot isolation and native/compatible protocols. Its HTTP double is below actual LangChain/vendor SDK serialization; do not replace these adapters with successful stubs. `test_managed_presets_live.py` requires explicit opt-in and vendor credentials, and remains skipped in CI.
 
+## Helm Redis credentials
+
+`test_helm_redis_existing_secret.py` renders the chart and executes its startup
+and both probe commands with argument-recording Redis stubs through
+`support.shell.require_posix_sh`. Keep missing/empty password keys, stale
+`redis.auth.password` values, Secret precedence, external mode and shell
+metacharacters covered.
+Render tests skip when Helm is unavailable; they need no Kubernetes cluster.
 ## Multi-instance harness
 
 Multi-instance harness tests use `support.shell.require_script_bash()` for shell
diff --git a/backend/tests/test_helm_redis_existing_secret.py b/backend/tests/test_helm_redis_existing_secret.py
new file mode 100644
index 0000000000..c1d00528b8
--- /dev/null
+++ b/backend/tests/test_helm_redis_existing_secret.py
@@ -0,0 +1,118 @@
+"""Bundled Redis and the Gateway must use the same Secret credentials."""
+
+from __future__ import annotations
+
+import os
+import shutil
+import subprocess
+from pathlib import Path
+from urllib.parse import unquote, urlsplit
+
+import pytest
+import yaml
+from support.shell import require_posix_sh
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+CHART = REPO_ROOT / "deploy" / "helm" / "deer-flow"
+PASSWORD = "p a$$'\"@:/?#%[]*"
+
+
+def _render_chart(*settings: str) -> list[dict]:
+    helm = shutil.which("helm")
+    if helm is None:
+        pytest.skip("helm is unavailable")
+    command = [helm, "template", "deer-flow", str(CHART)]
+    for setting in settings:
+        command.extend(["--set", setting])
+    rendered = subprocess.run(command, check=True, capture_output=True, text=True, encoding="utf-8").stdout
+    return [document for document in yaml.safe_load_all(rendered) if isinstance(document, dict)]
+
+
+def _container(documents: list[dict], name: str) -> dict:
+    workload = next(document for document in documents if document.get("kind") in {"Deployment", "StatefulSet"} and document["metadata"]["name"].endswith(f"-{name}"))
+    return next(container for container in workload["spec"]["template"]["spec"]["containers"] if container["name"] == name)
+
+
+def _secret_ref(container: dict, env_name: str) -> dict:
+    return next(item for item in container["env"] if item["name"] == env_name)["valueFrom"]["secretKeyRef"]
+
+
+def _run_command(command: list[str], tmp_path: Path, password: str | None) -> list[str]:
+    """Execute the rendered shell with argv-recording Redis executables."""
+    assert command[:2] == ["sh", "-c"]
+    for name in ("redis-server", "redis-cli"):
+        executable = tmp_path / name
+        executable.write_text(f"#!/bin/sh\nprintf '%s\\0' {name} \"$@\"\n", encoding="utf-8", newline="\n")
+        executable.chmod(0o755)
+    env = {key: value for key, value in os.environ.items() if key != "REDIS_PASSWORD"}
+    if password is not None:
+        env["REDIS_PASSWORD"] = password
+    # cd accepts native checkout paths in Git Bash, and pwd supplies its PATH form.
+    script = 'PATH="$(cd "$1" && pwd):$PATH"; export PATH; ' + command[2]
+    result = subprocess.run([require_posix_sh(), "-c", script, "_", tmp_path.as_posix()], env=env, check=True, capture_output=True, text=True, encoding="utf-8")
+    return result.stdout.rstrip("\0").split("\0")
+
+
+@pytest.mark.parametrize("password", ["", PASSWORD])
+def test_chart_managed_redis_credentials_match_the_gateway(password: str, tmp_path: Path) -> None:
+    documents = _render_chart(f"redis.auth.password={password}")
+    redis = _container(documents, "redis")
+    gateway_ref = _secret_ref(_container(documents, "gateway"), "DEER_FLOW_STREAM_BRIDGE_REDIS_URL")
+    secret = next(document for document in documents if document.get("kind") == "Secret" and document["metadata"]["name"] == gateway_ref["name"])
+    url = urlsplit(secret["stringData"][gateway_ref["key"]])
+    assert unquote(url.password or "") == password
+    assert url.hostname == gateway_ref["name"]
+    if password:
+        assert secret["stringData"]["redis-password"] == password
+        assert _secret_ref(redis, "REDIS_PASSWORD") == {"name": gateway_ref["name"], "key": "redis-password"}
+    else:
+        assert "redis-password" not in secret["stringData"]
+        assert "env" not in redis
+    expected_auth = ["--requirepass", password] if password else []
+    assert _run_command(redis["command"] + redis["args"], tmp_path, password or None) == ["redis-server", "--appendonly", "yes", *expected_auth]
+    for probe in ("readinessProbe", "livenessProbe"):
+        expected_auth = ["--no-auth-warning", "-a", password] if password else []
+        assert _run_command(redis[probe]["exec"]["command"], tmp_path, password or None) == ["redis-cli", *expected_auth, "ping"]
+
+
+@pytest.mark.parametrize("password", [None, "", PASSWORD])
+@pytest.mark.parametrize("ignored_password", ["", "ignored-values-password"])
+def test_bundled_redis_uses_optional_existing_secret_password(password: str | None, ignored_password: str, tmp_path: Path) -> None:
+    documents = _render_chart("redis.existingSecret=managed-redis", f"redis.auth.password={ignored_password}")
+    redis = _container(documents, "redis")
+    assert _secret_ref(redis, "REDIS_PASSWORD") == {"name": "managed-redis", "key": "redis-password", "optional": True}
+    assert _secret_ref(_container(documents, "gateway"), "DEER_FLOW_STREAM_BRIDGE_REDIS_URL") == {"name": "managed-redis", "key": "redis-url"}
+    assert not any(document.get("kind") == "Secret" and document["metadata"]["name"].endswith("-redis") for document in documents)
+    if ignored_password:
+        # The stale value must not leak into the manifest: it is the only input
+        # here that a template edit could accidentally start rendering.
+        assert ignored_password not in yaml.safe_dump(documents)
+    expected_auth = ["--requirepass", password] if password else []
+    assert _run_command(redis["command"] + redis["args"], tmp_path, password) == ["redis-server", "--appendonly", "yes", *expected_auth]
+    for probe in ("readinessProbe", "livenessProbe"):
+        argv = _run_command(redis[probe]["exec"]["command"], tmp_path, password)
+        assert argv == ["redis-cli", *(["--no-auth-warning", "-a", password] if password else []), "ping"]
+
+
+@pytest.mark.parametrize("enabled", ["true", "false"])
+def test_external_secret_precedence_is_unchanged(enabled: str) -> None:
+    # The existing helper gives external.existingSecret precedence in both modes.
+    documents = _render_chart(f"redis.enabled={enabled}", "redis.existingSecret=bundled-secret", "redis.external.existingSecret=external-secret")
+    assert _secret_ref(_container(documents, "gateway"), "DEER_FLOW_STREAM_BRIDGE_REDIS_URL") == {"name": "external-secret", "key": "redis-url"}
+    if enabled == "true":
+        assert _secret_ref(_container(documents, "redis"), "REDIS_PASSWORD") == {"name": "external-secret", "key": "redis-password", "optional": True}
+    else:
+        assert not any(document.get("kind") == "StatefulSet" and document["metadata"]["name"].endswith("-redis") for document in documents)
+    assert not any(document.get("kind") == "Secret" and document["metadata"]["name"].endswith("-redis") for document in documents)
+
+
+@pytest.mark.parametrize("setting", ["redis.existingSecret=managed-external", "redis.external.redisUrl=redis://:password@managed.example:6380/1"])
+def test_external_redis_does_not_deploy_a_bundled_instance(setting: str) -> None:
+    documents = _render_chart("redis.enabled=false", setting)
+    assert not any(document.get("kind") == "StatefulSet" and document["metadata"]["name"].endswith("-redis") for document in documents)
+    ref = _secret_ref(_container(documents, "gateway"), "DEER_FLOW_STREAM_BRIDGE_REDIS_URL")
+    if setting.startswith("redis.existingSecret="):
+        assert ref == {"name": "managed-external", "key": "redis-url"}
+    else:
+        secret = next(document for document in documents if document.get("kind") == "Secret" and document["metadata"]["name"] == ref["name"])
+        assert secret["stringData"] == {"redis-url": setting.split("=", 1)[1]}
diff --git a/deploy/helm/deer-flow/README.md b/deploy/helm/deer-flow/README.md
index db6d38879d..deec377e43 100644
--- a/deploy/helm/deer-flow/README.md
+++ b/deploy/helm/deer-flow/README.md
@@ -426,11 +426,15 @@ kubectl -n deer-flow exec deploy/deer-flow-provisioner -- curl -s localhost:8002
   auto-generated into a Secret (key `redis-url`) and injected as
   `DEER_FLOW_STREAM_BRIDGE_REDIS_URL`; `config.yaml` sets `stream_bridge.type:
   redis` by default. No-auth by default (ClusterIP isolation, matching compose);
-  set `redis.auth.password` to enable AUTH. For a managed Redis, disable the
-  bundled instance and point at it via `redis.external`. The gateway readiness
-  probe pings this Redis on every check and reports the pod unready while it
-  is unreachable, since without the bridge no run can publish, stream or be
-  cancelled from a peer pod.
+  set `redis.auth.password` to enable AUTH. A user-managed
+  `redis.existingSecret` takes precedence over that value: the bundled server
+  reads `redis-password` from the same Secret that supplies the gateway's
+  `redis-url`, and stays unauthenticated when that key is absent or empty — so
+  keep the URL and the raw password in agreement. For a managed Redis, disable
+  the bundled instance and point at it via `redis.external`. The gateway
+  readiness probe pings this Redis on every check and reports the pod unready
+  while it is unreachable, since without the bridge no run can publish, stream
+  or be cancelled from a peer pod.
 - **Persistence.** A PVC (`<release>-home`) backs `/app/backend/.deer-flow`
   (sqlite DB, memory, custom agents, per-thread user-data). The gateway mounts
   it with `subPath: deer-flow` so the layout matches the provisioner's PVC
diff --git a/deploy/helm/deer-flow/templates/_helpers.tpl b/deploy/helm/deer-flow/templates/_helpers.tpl
index cd3093845f..d3bbb6959c 100644
--- a/deploy/helm/deer-flow/templates/_helpers.tpl
+++ b/deploy/helm/deer-flow/templates/_helpers.tpl
@@ -157,9 +157,44 @@ imagePullSecrets:
        3. chart-managed secret `<release>-redis`
      Only #3 is created by this chart; #1/#2 must exist already. */}}
 {{- define "deer-flow.redisUrlSecret" -}}
-{{- if .Values.redis.external.existingSecret -}}{{- .Values.redis.external.existingSecret -}}
-{{- else if .Values.redis.existingSecret -}}{{- .Values.redis.existingSecret -}}
-{{- else -}}{{- include "deer-flow.redisFullname" . -}}{{- end -}}
+{{- include "deer-flow.redisUserSecret" . | default (include "deer-flow.redisFullname" .) -}}
+{{- end -}}
+
+{{/* Name of the operator-managed redis Secret, or empty when the chart owns the
+     credentials. Only the chart-managed Secret is created by this chart, and
+     only there is the AUTH password known at render time — a user-managed
+     Secret may or may not carry `redis-password`. */}}
+{{- define "deer-flow.redisUserSecret" -}}
+{{- or .Values.redis.external.existingSecret .Values.redis.existingSecret -}}
+{{- end -}}
+
+{{/* Args for the bundled redis container. With a user-managed Secret the
+     password is only knowable at runtime, so the container reads
+     `redis-password` from that Secret and enables AUTH only when the value is
+     nonempty. This keeps a `redis-url`-only Secret in no-auth mode instead of
+     failing to start, and keeps a stale `redis.auth.password` from winning over
+     the user-managed Secret (values.yaml documents it as ignored there). */}}
+{{- define "deer-flow.redisServerArgs" -}}
+{{- if include "deer-flow.redisUserSecret" . -}}
+if [ -n "$REDIS_PASSWORD" ]; then exec redis-server --appendonly yes --requirepass "$REDIS_PASSWORD"; fi; exec redis-server --appendonly yes
+{{- else if .Values.redis.auth.password -}}
+exec redis-server --appendonly yes --requirepass "$REDIS_PASSWORD"
+{{- else -}}
+exec redis-server --appendonly yes
+{{- end -}}
+{{- end -}}
+
+{{/* Readiness/liveness command for the bundled redis container. Mirrors
+     redisServerArgs so the probes authenticate exactly when the server has a
+     password — otherwise a password-protected server reports itself unhealthy. */}}
+{{- define "deer-flow.redisPingCommand" -}}
+{{- if include "deer-flow.redisUserSecret" . -}}
+if [ -n "$REDIS_PASSWORD" ]; then redis-cli --no-auth-warning -a "$REDIS_PASSWORD" ping; else redis-cli ping; fi
+{{- else if .Values.redis.auth.password -}}
+redis-cli --no-auth-warning -a "$REDIS_PASSWORD" ping
+{{- else -}}
+redis-cli ping
+{{- end -}}
 {{- end -}}
 
 {{/* Whether any redis stream-bridge backend is configured (bundled StatefulSet,
diff --git a/deploy/helm/deer-flow/templates/redis-secret.yaml b/deploy/helm/deer-flow/templates/redis-secret.yaml
index 50035545c6..b11b726fd2 100644
--- a/deploy/helm/deer-flow/templates/redis-secret.yaml
+++ b/deploy/helm/deer-flow/templates/redis-secret.yaml
@@ -8,11 +8,15 @@
   NOT created when the user manages the Secret themselves:
     • redis.external.existingSecret OR redis.existingSecret           → referenced only
 
-  Auth: empty `redis.auth.password` (default) = no auth, matching the compose
-  deployment (ClusterIP isolation only). Set a password to enable ACL/AUTH;
-  the DSN then becomes redis://:<password>@host:6379/0.
+  Bundled AUTH with chart-managed credentials: empty `redis.auth.password`
+  (default) = no auth, matching compose (ClusterIP isolation only). A nonempty
+  password enables AUTH and a redis://:<password>@host:6379/0 DSN.
+  With a user-managed Secret, `redis.auth.password` is ignored: its optional
+  `redis-password` key enables AUTH at runtime only when nonempty. An absent or
+  empty key keeps no-auth mode; the Secret's `redis-url` must match that choice.
+  External Redis authentication is configured through its `redis-url`.
 */ -}}
-{{- $userSecret := or .Values.redis.external.existingSecret .Values.redis.existingSecret -}}
+{{- $userSecret := include "deer-flow.redisUserSecret" . -}}
 {{- $wrapExternal := and (not .Values.redis.enabled) .Values.redis.external.redisUrl -}}
 {{- if and (not $userSecret) (or .Values.redis.enabled $wrapExternal) -}}
 {{- $password := .Values.redis.auth.password -}}
diff --git a/deploy/helm/deer-flow/templates/redis-statefulset.yaml b/deploy/helm/deer-flow/templates/redis-statefulset.yaml
index a094830919..a846a021af 100644
--- a/deploy/helm/deer-flow/templates/redis-statefulset.yaml
+++ b/deploy/helm/deer-flow/templates/redis-statefulset.yaml
@@ -1,5 +1,8 @@
 {{- if .Values.redis.enabled -}}
 {{- $password := .Values.redis.auth.password -}}
+{{- /* A user-managed Secret wins over `redis.auth.password` (see values.yaml),
+       and whether it carries `redis-password` is only knowable at runtime. */ -}}
+{{- $userSecret := include "deer-flow.redisUserSecret" . -}}
 apiVersion: apps/v1
 kind: StatefulSet
 metadata:
@@ -43,7 +46,19 @@ spec:
           ports:
             - name: tcp-redis
               containerPort: 6379
-          {{- if $password }}
+          {{- if $userSecret }}
+          # AUTH password is read from the operator-managed Secret at runtime so
+          # it never appears in the pod spec. The key is optional there: a
+          # Secret carrying only `redis-url` keeps the bundled server
+          # unauthenticated, which is what the chart's Secret contract allows.
+          env:
+            - name: REDIS_PASSWORD
+              valueFrom:
+                secretKeyRef:
+                  name: {{ include "deer-flow.redisUrlSecret" . }}
+                  key: redis-password
+                  optional: true
+          {{- else if $password }}
           # AUTH password is read at runtime so it never appears in the pod spec
           # args. `redis-server --requirepass` + `redis-cli -a` both read it
           # from this env.
@@ -56,13 +71,13 @@ spec:
           {{- end }}
           command: ["sh", "-c"]
           args:
-            - exec redis-server --appendonly yes{{ if $password }} --requirepass "$REDIS_PASSWORD"{{ end }}
+            - {{ include "deer-flow.redisServerArgs" . | quote }}
           readinessProbe:
             exec:
               command:
                 - sh
                 - -c
-                - {{ if $password }}redis-cli --no-auth-warning -a "$REDIS_PASSWORD" ping{{ else }}redis-cli ping{{ end }}
+                - {{ include "deer-flow.redisPingCommand" . | quote }}
             initialDelaySeconds: 5
             periodSeconds: 10
           livenessProbe:
@@ -70,7 +85,7 @@ spec:
               command:
                 - sh
                 - -c
-                - {{ if $password }}redis-cli --no-auth-warning -a "$REDIS_PASSWORD" ping{{ else }}redis-cli ping{{ end }}
+                - {{ include "deer-flow.redisPingCommand" . | quote }}
             initialDelaySeconds: 30
             periodSeconds: 20
           {{- with .Values.redis.primary.resources }}