fix(custom): support extraHeaders for OpenAI-compatible endpoints

nanobot/cli/commands.py

@@ -364,6 +364,7 @@ def _make_provider(config: Config):
             api_key=p.api_key if p else "no-key",
             api_base=config.get_api_base(model) or "http://localhost:8000/v1",
             default_model=model,
+            extra_headers=p.extra_headers if p else None,
         )
     # Azure OpenAI: direct Azure OpenAI endpoint with deployment name
     elif provider_name == "azure_openai":

nanobot/providers/custom_provider.py

@@ -13,14 +13,25 @@ from nanobot.providers.base import LLMProvider, LLMResponse, ToolCallRequest
 
 class CustomProvider(LLMProvider):
 
-    def __init__(self, api_key: str = "no-key", api_base: str = "http://localhost:8000/v1", default_model: str = "default"):
+    def __init__(
+        self,
+        api_key: str = "no-key",
+        api_base: str = "http://localhost:8000/v1",
+        default_model: str = "default",
+        extra_headers: dict[str, str] | None = None,
+    ):
         super().__init__(api_key, api_base)
         self.default_model = default_model
-        # Keep affinity stable for this provider instance to improve backend cache locality.
+        # Keep affinity stable for this provider instance to improve backend cache locality,
+        # while still letting users attach provider-specific headers for custom gateways.
+        default_headers = {
+            "x-session-affinity": uuid.uuid4().hex,
+            **(extra_headers or {}),
+        }
         self._client = AsyncOpenAI(
             api_key=api_key,
             base_url=api_base,
-            default_headers={"x-session-affinity": uuid.uuid4().hex},
+            default_headers=default_headers,
         )
 
     async def chat(self, messages: list[dict[str, Any]], tools: list[dict[str, Any]] | None = None,

tests/test_commands.py

@@ -6,7 +6,7 @@ from unittest.mock import AsyncMock, MagicMock, patch
 import pytest
 from typer.testing import CliRunner
 
-from nanobot.cli.commands import app
+from nanobot.cli.commands import _make_provider, app
 from nanobot.config.schema import Config
 from nanobot.providers.litellm_provider import LiteLLMProvider
 from nanobot.providers.openai_codex_provider import _strip_model_prefix
@@ -199,6 +199,33 @@ def test_openai_codex_strip_prefix_supports_hyphen_and_underscore():
     assert _strip_model_prefix("openai_codex/gpt-5.1-codex") == "gpt-5.1-codex"
 
 
+def test_make_provider_passes_extra_headers_to_custom_provider():
+    config = Config.model_validate(
+        {
+            "agents": {"defaults": {"provider": "custom", "model": "gpt-4o-mini"}},
+            "providers": {
+                "custom": {
+                    "apiKey": "test-key",
+                    "apiBase": "https://example.com/v1",
+                    "extraHeaders": {
+                        "APP-Code": "demo-app",
+                        "x-session-affinity": "sticky-session",
+                    },
+                }
+            },
+        }
+    )
+
+    with patch("nanobot.providers.custom_provider.AsyncOpenAI") as mock_async_openai:
+        _make_provider(config)
+
+    kwargs = mock_async_openai.call_args.kwargs
+    assert kwargs["api_key"] == "test-key"
+    assert kwargs["base_url"] == "https://example.com/v1"
+    assert kwargs["default_headers"]["APP-Code"] == "demo-app"
+    assert kwargs["default_headers"]["x-session-affinity"] == "sticky-session"
+
+
 @pytest.fixture
 def mock_agent_runtime(tmp_path):
     """Mock agent command dependencies for focused CLI tests."""