diff --git a/custom_components/openai_compatible/__init__.py b/custom_components/openai_compatible/__init__.py
index cb67c46..459338a 100644
--- a/custom_components/openai_compatible/__init__.py
+++ b/custom_components/openai_compatible/__init__.py
@@ -54,6 +54,7 @@ from .const import (
     DEFAULT_TTS_NAME,
     DOMAIN,
     LOGGER,
+    PLACEHOLDER_API_KEY,
     RECOMMENDED_AI_TASK_OPTIONS,
     RECOMMENDED_CHAT_MODEL,
     RECOMMENDED_MAX_TOKENS,
@@ -282,7 +283,7 @@ async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
 async def async_setup_entry(hass: HomeAssistant, entry: OpenAIConfigEntry) -> bool:
     """Set up OpenAI Conversation from a config entry."""
     client = openai.AsyncOpenAI(
-        api_key=entry.data[CONF_API_KEY],
+        api_key=entry.data.get(CONF_API_KEY) or PLACEHOLDER_API_KEY,
         base_url=entry.data[CONF_BASE_URL],
         http_client=get_async_client(hass),
     )
diff --git a/custom_components/openai_compatible/config_flow.py b/custom_components/openai_compatible/config_flow.py
index 2c4da64..0940a27 100644
--- a/custom_components/openai_compatible/config_flow.py
+++ b/custom_components/openai_compatible/config_flow.py
@@ -74,6 +74,7 @@ from .const import (
     DEFAULT_STT_PROMPT,
     DEFAULT_TTS_NAME,
     DOMAIN,
+    PLACEHOLDER_API_KEY,
     RECOMMENDED_AI_TASK_OPTIONS,
     RECOMMENDED_CHAT_MODEL,
     RECOMMENDED_CODE_INTERPRETER,
@@ -110,7 +111,7 @@ _LOGGER = logging.getLogger(__name__)
 STEP_USER_DATA_SCHEMA = vol.Schema(
     {
         vol.Required(CONF_BASE_URL, default=DEFAULT_BASE_URL): str,
-        vol.Required(CONF_API_KEY): str,
+        vol.Optional(CONF_API_KEY, default=""): str,
     }
 )
 
@@ -122,7 +123,7 @@ async def validate_input(hass: HomeAssistant, data: dict[str, Any]) -> None:
     """
     data[CONF_BASE_URL] = normalize_base_url(data[CONF_BASE_URL])
     client = openai.AsyncOpenAI(
-        api_key=data[CONF_API_KEY],
+        api_key=data.get(CONF_API_KEY) or PLACEHOLDER_API_KEY,
         base_url=data[CONF_BASE_URL],
         http_client=get_async_client(hass),
     )
@@ -654,7 +655,7 @@ class OpenAISubentryFlowHandler(ConfigSubentryFlow):
         zone_home = self.hass.states.get(ENTITY_ID_HOME)
         if zone_home is not None:
             client = openai.AsyncOpenAI(
-                api_key=self._get_entry().data[CONF_API_KEY],
+                api_key=self._get_entry().data.get(CONF_API_KEY) or PLACEHOLDER_API_KEY,
                 base_url=self._get_entry().data[CONF_BASE_URL],
                 http_client=get_async_client(self.hass),
             )
diff --git a/custom_components/openai_compatible/const.py b/custom_components/openai_compatible/const.py
index 000d88c..43bb5c4 100644
--- a/custom_components/openai_compatible/const.py
+++ b/custom_components/openai_compatible/const.py
@@ -11,6 +11,7 @@ LOGGER: logging.Logger = logging.getLogger(__package__)
 
 CONF_BASE_URL = "base_url"
 DEFAULT_BASE_URL = "https://api.openai.com/v1"
+PLACEHOLDER_API_KEY = "not-required"
 
 DEFAULT_CONVERSATION_NAME = "OpenAI Conversation"
 DEFAULT_AI_TASK_NAME = "OpenAI AI Task"
diff --git a/tests/test_base_url.py b/tests/test_base_url.py
index 420b9e1..2e14217 100644
--- a/tests/test_base_url.py
+++ b/tests/test_base_url.py
@@ -25,3 +25,22 @@ async def test_client_built_with_base_url(hass: HomeAssistant) -> None:
         await hass.async_block_till_done()
 
     assert mock_client.call_args.kwargs["base_url"] == "http://192.0.2.10:4000/v1"
+
+
+async def test_api_key_optional(hass: HomeAssistant) -> None:
+    """An endpoint needing no auth should still set up."""
+    entry = MockConfigEntry(
+        domain=DOMAIN,
+        data={CONF_BASE_URL: "http://192.0.2.10:4000/v1"},
+    )
+    entry.add_to_hass(hass)
+
+    with patch(
+        "custom_components.openai_compatible.openai.AsyncOpenAI"
+    ) as mock_client:
+        mock_client.return_value.platform_headers = lambda: {}
+        mock_client.return_value.with_options.return_value.models.list = AsyncMock()
+        await hass.config_entries.async_setup(entry.entry_id)
+        await hass.async_block_till_done()
+
+    assert mock_client.call_args.kwargs["api_key"] == "not-required"