diff --git a/hermes_cli/auth.py b/hermes_cli/auth.py
index 98b354715f80..fa1113d512fc 100644
--- a/hermes_cli/auth.py
+++ b/hermes_cli/auth.py
@@ -4452,7 +4452,15 @@ def _save_xai_oauth_tokens(
     redirect_uri: str = "",
     last_refresh: Optional[str] = None,
     auth_mode: str = "oauth_device_code",
+    set_active: bool = True,
 ) -> None:
+    """Persist xAI OAuth tokens into the auth store.
+
+    When *set_active* is True (default), also promote ``xai-oauth`` to
+    ``active_provider`` — appropriate for intentional model/auth login.
+    Pass ``set_active=False`` for side-tool credential bootstrap (TTS, STT,
+    dashboard token save, token refresh) so inference routing is unchanged.
+    """
     if last_refresh is None:
         last_refresh = datetime.now(timezone.utc).isoformat().replace("+00:00", "Z")
     with _auth_store_lock():
@@ -4470,7 +4478,9 @@ def _save_xai_oauth_tokens(
             state["discovery"] = discovery
         if redirect_uri:
             state["redirect_uri"] = redirect_uri
-        _save_provider_state(auth_store, "xai-oauth", state)
+        _store_provider_state(
+            auth_store, "xai-oauth", state, set_active=set_active
+        )
         _save_auth_store(auth_store)
         if write_through_to_root:
             _write_through_xai_oauth_to_global_root(state)
@@ -4808,6 +4818,9 @@ def _refresh_xai_oauth_tokens(
         redirect_uri=redirect_uri,
         last_refresh=refreshed["last_refresh"],
         auth_mode=auth_mode,
+        # Refresh must not flip active_provider — TTS/side tools can refresh
+        # xAI tokens while chat still routes through another provider.
+        set_active=False,
     )
     return updated_tokens
 
diff --git a/hermes_cli/setup.py b/hermes_cli/setup.py
index 0f4d413d795b..d782d89016f5 100644
--- a/hermes_cli/setup.py
+++ b/hermes_cli/setup.py
@@ -896,15 +896,17 @@ def _xai_oauth_logged_in_for_setup() -> bool:
 def _run_xai_oauth_login_from_setup() -> bool:
     """Run the xAI Grok OAuth device-code login from inside the setup wizard.
 
+    Saves OAuth tokens only. Does **not** switch the active inference
+    provider or rewrite ``model.provider`` — callers (TTS setup, tools
+    config) only need credentials for side tools.
+
     Returns True on success, False on any failure (the caller falls back
     to whatever the user picked next, e.g. Edge TTS).
     """
     try:
         from hermes_cli.auth import (
-            DEFAULT_XAI_OAUTH_BASE_URL,
             _is_remote_session,
             _save_xai_oauth_tokens,
-            _update_config_for_provider,
             _xai_oauth_device_code_login,
         )
     except Exception as exc:
@@ -922,9 +924,7 @@ def _run_xai_oauth_login_from_setup() -> bool:
             redirect_uri=creds.get("redirect_uri", ""),
             last_refresh=creds.get("last_refresh"),
             auth_mode="oauth_device_code",
-        )
-        _update_config_for_provider(
-            "xai-oauth", creds.get("base_url", DEFAULT_XAI_OAUTH_BASE_URL)
+            set_active=False,
         )
         return True
     except Exception as exc:
diff --git a/hermes_cli/web_server.py b/hermes_cli/web_server.py
index 8925827637ec..b98cf8ce9fb4 100644
--- a/hermes_cli/web_server.py
+++ b/hermes_cli/web_server.py
@@ -11153,6 +11153,9 @@ def _xai_device_poller(session_id: str) -> None:
                 discovery=discovery,
                 last_refresh=datetime.now(timezone.utc).isoformat().replace("+00:00", "Z"),
                 auth_mode="oauth_device_code",
+                # Dashboard OAuth only bootstraps credentials for side tools;
+                # do not hijack the active chat inference provider.
+                set_active=False,
             )
             # The singleton write above is the single source of truth: the
             # credential-pool load seeds it as the canonical ``device_code``
diff --git a/tests/hermes_cli/test_auth_xai_oauth_provider.py b/tests/hermes_cli/test_auth_xai_oauth_provider.py
index eae404c28c05..7210fd5e03e7 100644
--- a/tests/hermes_cli/test_auth_xai_oauth_provider.py
+++ b/tests/hermes_cli/test_auth_xai_oauth_provider.py
@@ -281,6 +281,40 @@ def test_save_and_read_xai_oauth_tokens_roundtrip(tmp_path, monkeypatch):
     assert data["discovery"]["token_endpoint"] == "https://auth.x.ai/oauth2/token"
 
 
+def test_save_xai_oauth_tokens_set_active_false_preserves_active_provider(
+    tmp_path, monkeypatch
+):
+    """Side-tool credential saves must not flip auth.json active_provider."""
+    hermes_home = tmp_path / "hermes"
+    hermes_home.mkdir(parents=True, exist_ok=True)
+    auth_path = hermes_home / "auth.json"
+    auth_path.write_text(
+        json.dumps(
+            {
+                "version": 1,
+                "active_provider": "openrouter",
+                "providers": {},
+            }
+        )
+    )
+    monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+    _save_xai_oauth_tokens(
+        {
+            "access_token": "side-tool-at",
+            "refresh_token": "side-tool-rt",
+            "id_token": "",
+            "token_type": "Bearer",
+        },
+        discovery={"token_endpoint": "https://auth.x.ai/oauth2/token"},
+        set_active=False,
+    )
+
+    raw = json.loads(auth_path.read_text())
+    assert raw["active_provider"] == "openrouter"
+    assert raw["providers"]["xai-oauth"]["tokens"]["access_token"] == "side-tool-at"
+
+
 def test_read_xai_oauth_tokens_missing(tmp_path, monkeypatch):
     hermes_home = tmp_path / "hermes"
     hermes_home.mkdir(parents=True, exist_ok=True)
diff --git a/tests/hermes_cli/test_setup_tts_xai_oauth.py b/tests/hermes_cli/test_setup_tts_xai_oauth.py
new file mode 100644
index 000000000000..d8416b831944
--- /dev/null
+++ b/tests/hermes_cli/test_setup_tts_xai_oauth.py
@@ -0,0 +1,78 @@
+"""Regression: TTS/setup xAI OAuth must not hijack the active chat provider."""
+
+import json
+
+import yaml
+
+
+def test_run_xai_oauth_login_from_setup_does_not_hijack_active_provider(
+    tmp_path, monkeypatch
+):
+    """TTS/setup OAuth must save tokens without switching chat inference routing.
+
+    Regression: `_run_xai_oauth_login_from_setup` used to call
+    `_update_config_for_provider("xai-oauth")` (and token save flipped
+    `active_provider`), so `hermes setup tts` OAuth login hijacked the main
+    chat provider.
+    """
+    hermes_home = tmp_path / "hermes"
+    hermes_home.mkdir(parents=True, exist_ok=True)
+    monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+    auth_path = hermes_home / "auth.json"
+    auth_path.write_text(
+        json.dumps(
+            {
+                "version": 1,
+                "active_provider": "openrouter",
+                "providers": {},
+            }
+        ),
+        encoding="utf-8",
+    )
+    config_path = hermes_home / "config.yaml"
+    config_path.write_text(
+        yaml.safe_dump(
+            {
+                "model": {
+                    "provider": "openrouter",
+                    "default": "anthropic/claude-sonnet-4",
+                    "base_url": "https://openrouter.ai/api/v1",
+                },
+                "tts": {"provider": "edge"},
+            }
+        ),
+        encoding="utf-8",
+    )
+
+    monkeypatch.setattr(
+        "hermes_cli.auth._xai_oauth_device_code_login",
+        lambda **kwargs: {
+            "tokens": {
+                "access_token": "tts-xai-access",
+                "refresh_token": "tts-xai-refresh",
+                "id_token": "",
+                "token_type": "Bearer",
+            },
+            "discovery": {"token_endpoint": "https://auth.x.ai/oauth2/token"},
+            "redirect_uri": "",
+            "base_url": "https://api.x.ai/v1",
+            "last_refresh": "2026-07-25T12:00:00Z",
+        },
+    )
+    monkeypatch.setattr("hermes_cli.auth._is_remote_session", lambda: True)
+
+    from hermes_cli.setup import _run_xai_oauth_login_from_setup
+
+    assert _run_xai_oauth_login_from_setup() is True
+
+    auth = json.loads(auth_path.read_text(encoding="utf-8"))
+    assert auth["active_provider"] == "openrouter"
+    xai_state = auth["providers"]["xai-oauth"]
+    assert xai_state["tokens"]["access_token"] == "tts-xai-access"
+    assert xai_state["tokens"]["refresh_token"] == "tts-xai-refresh"
+
+    config = yaml.safe_load(config_path.read_text(encoding="utf-8"))
+    assert config["model"]["provider"] == "openrouter"
+    assert config["model"]["base_url"] == "https://openrouter.ai/api/v1"
+    assert config["model"]["default"] == "anthropic/claude-sonnet-4"