diff --git a/backend/packages/harness/deerflow/AGENTS.md b/backend/packages/harness/deerflow/AGENTS.md
index d1abe445e9..737721d834 100644
--- a/backend/packages/harness/deerflow/AGENTS.md
+++ b/backend/packages/harness/deerflow/AGENTS.md
@@ -102,6 +102,10 @@ policy or network-mode mismatch; only the provider may replace it after the
 orphan grace, local teardown reservation, and cross-instance teardown lease.
 Destroy the sandbox, sidecar, and both networks together.
 
+### Tenki `sticky`
+
+Env values stay strings; parse booleans before SDK calls (`bool("false")` is true).
+
 ### E2B Mount Uploads
 
 E2B uploads host mounts during sandbox creation using binary file objects.
diff --git a/backend/packages/harness/deerflow/community/tenki/README.md b/backend/packages/harness/deerflow/community/tenki/README.md
index e1fa35f872..52769099bc 100644
--- a/backend/packages/harness/deerflow/community/tenki/README.md
+++ b/backend/packages/harness/deerflow/community/tenki/README.md
@@ -25,6 +25,12 @@ sandbox:
     PYTHONUNBUFFERED: "1"
 ```
 
+`sticky` also accepts an environment reference such as `sticky: $TENKI_STICKY`.
+Boolean strings are case-insensitive: `false`, `0`, `off`, and `no` disable host
+pinning; `true`, `1`, `on`, and `yes` enable it. Invalid boolean values are
+rejected when the provider loads its configuration. Omitted or `null` values
+keep pinning disabled.
+
 Install the optional SDK before selecting this provider:
 
 ```bash
diff --git a/backend/packages/harness/deerflow/community/tenki/provider.py b/backend/packages/harness/deerflow/community/tenki/provider.py
index 43b3fe25f7..8b6b8f7d6e 100644
--- a/backend/packages/harness/deerflow/community/tenki/provider.py
+++ b/backend/packages/harness/deerflow/community/tenki/provider.py
@@ -26,6 +26,8 @@ import uuid
 from functools import partial
 from typing import TYPE_CHECKING, Any
 
+from pydantic import TypeAdapter
+
 from deerflow.config import get_app_config
 from deerflow.sandbox.acquire_serialization import AcquireSerializer
 from deerflow.sandbox.identity import derive_sandbox_scope_token
@@ -141,6 +143,7 @@ class TenkiSandboxProvider(WarmPoolLifecycleMixin[TenkiSandbox], SandboxProvider
         replicas = _opt("replicas")
         idle_timeout = _opt("idle_timeout")
         max_duration = _opt("max_duration")
+        sticky = _opt("sticky", False)
         environment = dict(_opt("environment") or {})
         # Fail fast on a misconfigured key (e.g. "bad-key"): the per-call env goes
         # through the same POSIX-name check in execute_command, but this static
@@ -159,7 +162,7 @@ class TenkiSandboxProvider(WarmPoolLifecycleMixin[TenkiSandbox], SandboxProvider
             # Off by default (the SDK default). Warm-pool sandboxes stay running
             # between turns, so host pinning only matters to deployments that
             # also pause/resume; expose it rather than decide for them.
-            "sticky": bool(_opt("sticky", False)),
+            "sticky": TypeAdapter(bool).validate_python(sticky) if sticky is not None else False,
             "api_key": api_key,  # None → SDK falls back to TENKI_API_KEY / TENKI_AUTH_TOKEN
             "base_url": _opt("base_url"),
             "image": _opt("image"),  # None → Tenki account default base image
diff --git a/backend/tests/test_tenki_provider.py b/backend/tests/test_tenki_provider.py
index 0ee85e0ddc..5f3b552207 100644
--- a/backend/tests/test_tenki_provider.py
+++ b/backend/tests/test_tenki_provider.py
@@ -25,6 +25,7 @@ import pytest
 
 from deerflow.community.tenki.provider import _BOOTSTRAP_TIMEOUT, TenkiSandboxProvider, _import_client
 from deerflow.community.tenki.sandbox import TenkiSandbox
+from deerflow.config.app_config import AppConfig
 
 # ── Fake Tenki SDK ────────────────────────────────────────────────────
 
@@ -755,6 +756,42 @@ def test_create_waits_client_side_and_configures_lifetime(monkeypatch):
     provider.shutdown()
 
 
+@pytest.mark.parametrize(
+    ("value", "expected"),
+    [("false", False), ("0", False), ("off", False), ("no", False), ("FALSE", False), ("true", True), ("1", True), ("on", True), ("yes", True)],
+)
+def test_create_sticky_from_environment(monkeypatch, tmp_path, value, expected):
+    monkeypatch.setenv("TEST_TENKI_STICKY", value)
+    config_path = tmp_path / "config.yaml"
+    config_path.write_text("models: []\nsandbox:\n  use: deerflow.community.tenki:TenkiSandboxProvider\n  sticky: $TEST_TENKI_STICKY\n  idle_timeout: 0\n", encoding="utf-8")
+    config = AppConfig.from_file(config_path)
+    client = _FakeClient()
+    monkeypatch.setattr("deerflow.community.tenki.provider.get_app_config", lambda: config)
+    monkeypatch.setattr("deerflow.community.tenki.provider._import_client", lambda: lambda **kw: client)
+    provider = TenkiSandboxProvider()
+    try:
+        provider.acquire("thread-1", user_id="u1")
+        assert client.create_kwargs[0]["sticky"] is expected
+    finally:
+        provider.shutdown()
+
+
+@pytest.mark.parametrize("value", [False, True, None])
+def test_create_sticky_native_value(monkeypatch, value):
+    client = _FakeClient()
+    provider = _install(monkeypatch, client=client, config_attrs={"sticky": value, "idle_timeout": 0})
+    try:
+        provider.acquire("thread-1", user_id="u1")
+        assert client.create_kwargs[0]["sticky"] is bool(value)
+    finally:
+        provider.shutdown()
+
+
+def test_sticky_rejects_invalid_boolean(monkeypatch):
+    with pytest.raises(ValueError, match="valid boolean"):
+        _install(monkeypatch, config_attrs={"sticky": "not-a-boolean"})
+
+
 def test_create_default_lifetime_is_explicit(monkeypatch):
     client = _FakeClient()
     provider = _install(monkeypatch, client=client)