diff --git a/acp_adapter/session.py b/acp_adapter/session.py
index c124229bec8..bbe34b06789 100644
--- a/acp_adapter/session.py
+++ b/acp_adapter/session.py
@@ -617,6 +617,10 @@ class SessionManager:
 
         _register_task_cwd(session_id, cwd)
         agent = AIAgent(**kwargs)
+        # Codex app-server sessions are spawned lazily on the first turn. Stamp
+        # the ACP workspace onto the agent so the Codex runtime starts from the
+        # editor/session cwd instead of the Hermes daemon's process cwd.
+        agent.session_cwd = cwd
         # ACP stdio transport requires stdout to remain protocol-only JSON-RPC.
         # Route any incidental human-readable agent output to stderr instead.
         agent._print_fn = _acp_stderr_print
diff --git a/agent/codex_runtime.py b/agent/codex_runtime.py
index 9928c07878c..e638a194159 100644
--- a/agent/codex_runtime.py
+++ b/agent/codex_runtime.py
@@ -250,7 +250,9 @@ def run_codex_app_server_turn(
     # Spawned on first turn, reused across turns, closed at AIAgent
     # shutdown (see _cleanup hook).
     if not hasattr(agent, "_codex_session") or agent._codex_session is None:
-        cwd = getattr(agent, "session_cwd", None) or os.getcwd()
+        from agent.runtime_cwd import resolve_agent_cwd
+
+        cwd = getattr(agent, "session_cwd", None) or str(resolve_agent_cwd())
         # Approval callback: defer to Hermes' standard prompt flow if a
         # CLI thread has installed one. Gateway / cron contexts get the
         # codex-side fail-closed default.
diff --git a/tests/acp/test_session.py b/tests/acp/test_session.py
index 3bfe64a2213..5ff5e08b807 100644
--- a/tests/acp/test_session.py
+++ b/tests/acp/test_session.py
@@ -77,6 +77,50 @@ class TestCreateSession:
     def test_get_nonexistent_session_returns_none(self, manager):
         assert manager.get_session("does-not-exist") is None
 
+    def test_make_agent_stamps_session_cwd_for_codex_runtime(self, monkeypatch):
+        class FakeAgent:
+            model = "fake-model"
+
+            def __init__(self, **kwargs):
+                self.kwargs = kwargs
+
+        monkeypatch.setattr("run_agent.AIAgent", FakeAgent)
+        monkeypatch.setattr(
+            "acp_adapter.session.load_config",
+            lambda: {
+                "model": {
+                    "default": "fake-model",
+                    "provider": "fake-provider",
+                },
+                "mcp_servers": {},
+            },
+            raising=False,
+        )
+        monkeypatch.setattr(
+            "hermes_cli.config.load_config",
+            lambda: {
+                "model": {
+                    "default": "fake-model",
+                    "provider": "fake-provider",
+                },
+                "mcp_servers": {},
+            },
+        )
+        monkeypatch.setattr(
+            "hermes_cli.runtime_provider.resolve_runtime_provider",
+            lambda requested=None: {
+                "provider": requested,
+                "api_mode": "codex_app_server",
+                "base_url": "https://example.invalid",
+                "api_key": "test-key",
+            },
+        )
+        monkeypatch.setattr("acp_adapter.session._register_task_cwd", lambda task_id, cwd: None)
+
+        state = SessionManager(db=None).create_session(cwd="/tmp/project")
+
+        assert state.agent.session_cwd == "/tmp/project"
+
 
 
 
diff --git a/tests/run_agent/test_codex_app_server_integration.py b/tests/run_agent/test_codex_app_server_integration.py
index b1de32a3302..7c5ac4f83c7 100644
--- a/tests/run_agent/test_codex_app_server_integration.py
+++ b/tests/run_agent/test_codex_app_server_integration.py
@@ -293,6 +293,39 @@ class TestRunConversationCodexPath:
             agent.run_conversation("hi")
         assert not client_mock.chat.completions.create.called
 
+    def test_gateway_terminal_cwd_seeds_codex_thread_cwd(self, monkeypatch, tmp_path):
+        """Gateway sessions set TERMINAL_CWD without stamping agent.session_cwd.
+        Codex app-server must still start in that configured workspace instead
+        of falling back to the Hermes daemon process cwd."""
+        from agent.transports.codex_app_server_session import (
+            CodexAppServerSession, TurnResult,
+        )
+
+        captured: dict[str, str] = {}
+
+        def fake_init(self, **kwargs):
+            captured["cwd"] = kwargs["cwd"]
+            self._thread_id = "thread-stub-1"
+
+        def fake_run_turn(self, user_input: str, **kwargs):
+            return TurnResult(
+                final_text="ok",
+                projected_messages=[{"role": "assistant", "content": "ok"}],
+                turn_id="turn-stub-1",
+                thread_id="thread-stub-1",
+            )
+
+        monkeypatch.setenv("TERMINAL_CWD", str(tmp_path))
+        monkeypatch.setattr(CodexAppServerSession, "__init__", fake_init)
+        monkeypatch.setattr(CodexAppServerSession, "run_turn", fake_run_turn)
+
+        agent = _make_codex_agent()
+        assert not hasattr(agent, "session_cwd")
+        with patch.object(agent, "_spawn_background_review", return_value=None):
+            agent.run_conversation("hi")
+
+        assert captured["cwd"] == str(tmp_path)
+
 
 class TestReviewForkApiModeDowngrade:
     """When the parent agent runs on codex_app_server, the background