diff --git a/benchmark/runtime/sforge.py b/benchmark/runtime/sforge.py
index 1218ba3a3c..a9b983f4f9 100644
--- a/benchmark/runtime/sforge.py
+++ b/benchmark/runtime/sforge.py
@@ -216,6 +216,10 @@ def __init__(self, config, *, profile: str, cwd: str,
         # workers already run a scheduler: restarting it after terminal/quiescent
         # exit duplicates that owner and can exhaust the native resume limit.
         self.resume_cmd = CodexAgent.resume_cmd if profile == "official" else None
+        # SForge signs this declaration into the runtime protocol.  The setup
+        # callback below is shared by every profile, but only the official
+        # profile installs the Codex stop hook inside that callback.
+        self.stop_hook = CodexAgent.stop_hook if profile == "official" else None
 
     def install_stop_hook(self, backend, handle, log_dir, logger):
         self.environment = SForgeEnvironment(
diff --git a/benchmark/tests/test_sforge_runtime.py b/benchmark/tests/test_sforge_runtime.py
index 60dae42b34..e8f1ca0fe5 100644
--- a/benchmark/tests/test_sforge_runtime.py
+++ b/benchmark/tests/test_sforge_runtime.py
@@ -77,7 +77,8 @@ def test_scheduler_modes_do_not_add_an_outer_loop_to_native_goal():
     ("official", True), ("single", False), ("native-goal", False),
     ("heartbeat-resume", False), ("heartbeat-explore", False),
 ])
-def test_only_official_delegates_continuation_to_sforge(profile, resumes, monkeypatch):
+def test_only_official_delegates_continuation_and_stop_hook_to_sforge(
+        profile, resumes, monkeypatch):
     pytest.importorskip("sforge")
     pytest.importorskip("harbor")
     from sforge.harness.config import SForgeConfig
@@ -86,6 +87,7 @@ def test_only_official_delegates_continuation_to_sforge(profile, resumes, monkey
     worker = SForgeWorker(SForgeConfig(agent_model="fixture-model", agent_effort="xhigh"),
                           profile=profile, cwd="/task")
     assert (worker.resume_cmd is not None) is resumes
+    assert (worker.stop_hook is not None) is (profile == "official")
     assert worker.timeout_seconds == 64800
     assert worker.task_entry == ("loopx-planned" if profile.startswith("heartbeat-") else "seeded-todo")
     if profile in {"official", "single"}:
@@ -94,6 +96,32 @@ def test_only_official_delegates_continuation_to_sforge(profile, resumes, monkey
         assert 'web_search="disabled"' in command
 
 
+@pytest.mark.parametrize("profile", [
+    "official", "single", "native-goal", "heartbeat-resume", "heartbeat-explore",
+])
+def test_runtime_protocol_attests_only_official_stop_hook(profile, monkeypatch):
+    from types import SimpleNamespace
+    pytest.importorskip("sforge")
+    pytest.importorskip("harbor")
+    from sforge.harness.config import SForgeConfig
+    run_agent = pytest.importorskip("sforge.harness.run_agent")
+    runtime_protocol = getattr(run_agent, "_runtime_protocol", None)
+    if runtime_protocol is None:
+        pytest.skip("SForge provider does not expose the signed runtime protocol builder")
+    from benchmark.runtime.sforge import SForgeWorker
+    monkeypatch.setenv("CODEX_AUTH_JSON_PATH", "/private-credential")
+    worker = SForgeWorker(SForgeConfig(agent_model="fixture-model", agent_effort="xhigh"),
+                          profile=profile, cwd="/task")
+    protocol = runtime_protocol(
+        agent=worker, backend=SimpleNamespace(backend_name="docker"),
+        model="fixture-model", effective_timeout=64800, eval_interval=300,
+        disable_stop_hook=False, disable_auto_eval=False,
+        disable_auto_resume=False, internet=False, max_submissions=None,
+        submission_cooldown=3600,
+    )
+    assert protocol["stop_hook_enabled"] is (profile == "official")
+
+
 def test_invalid_worker_inputs_fail_before_install(monkeypatch):
     pytest.importorskip("sforge")
     pytest.importorskip("harbor")
@@ -353,7 +381,7 @@ async def installed(self, environment):
     assert profile.get("native_goal_continue") is (True if enabled else None)
     with pytest.raises(ValueError, match="native-goal"):
         SForgeWorker(config, profile="heartbeat-resume", cwd="/task", native_goal_continue=True)
-    with pytest.raises(ValueError, match="context_delivery"):
+    with pytest.raises(ValueError, match="native_goal_continue"):
         SForgeWorker(config, profile="native-goal", cwd="/task", native_goal_continue="1")