feat(llm): unify OpenAI-compatible providers behind a registry + generic endpoint

The OpenAI-compatible family (openai, xAI, DeepSeek, Qwen, GLM, MiniMax,
OpenRouter, Ollama) all speak the same Chat Completions API and differ only by
base_url, key, and two narrow wire-format quirks already isolated in subclasses.
Replace the scattered base-URL dict, key handling, and client-class branches with
one ProviderSpec registry that get_llm and the factory drive off; provider quirks
stay in their subclasses. Add a generic "openai_compatible" provider for any
OpenAI-compatible server (vLLM, LM Studio, llama.cpp, relays) via backend_url +
optional key — adding a provider is now one registry row. Native Anthropic/Google
keep their own clients (genuinely different APIs). Also fixes the env backend URL
being ignored when the provider was chosen interactively (#978).

tests/test_ollama_base_url.py

@@ -24,7 +24,7 @@ def _resync_reloaded_modules():
     importlib.reload(cli.main)
 
 
-# ---- openai_client side: _resolve_provider_base_url -----------------------
+# ---- openai_client side: registry-driven base_url resolution --------------
 
 
 def _reload_client():
@@ -32,16 +32,20 @@ def _reload_client():
     return importlib.reload(mod)
 
 
+def _base_url(mod, provider, **kwargs):
+    return str(mod.OpenAIClient(model="m", provider=provider, **kwargs).get_llm().openai_api_base)
+
+
 def test_resolver_returns_default_when_env_unset(monkeypatch):
     monkeypatch.delenv("OLLAMA_BASE_URL", raising=False)
     mod = _reload_client()
-    assert mod._resolve_provider_base_url("ollama") == "http://localhost:11434/v1"
+    assert _base_url(mod, "ollama") == "http://localhost:11434/v1"
 
 
 def test_resolver_returns_env_when_set(monkeypatch):
     monkeypatch.setenv("OLLAMA_BASE_URL", "http://remote-ollama:11434/v1")
     mod = _reload_client()
-    assert mod._resolve_provider_base_url("ollama") == "http://remote-ollama:11434/v1"
+    assert _base_url(mod, "ollama") == "http://remote-ollama:11434/v1"
 
 
 def test_resolver_evaluation_is_call_time(monkeypatch):
@@ -49,15 +53,15 @@ def test_resolver_evaluation_is_call_time(monkeypatch):
     monkeypatch.delenv("OLLAMA_BASE_URL", raising=False)
     mod = _reload_client()
     monkeypatch.setenv("OLLAMA_BASE_URL", "http://late-set:11434/v1")
-    assert mod._resolve_provider_base_url("ollama") == "http://late-set:11434/v1"
+    assert _base_url(mod, "ollama") == "http://late-set:11434/v1"
 
 
 def test_resolver_does_not_affect_other_providers(monkeypatch):
     """OLLAMA_BASE_URL should NOT leak into xai/deepseek/etc."""
     monkeypatch.setenv("OLLAMA_BASE_URL", "http://elsewhere/v1")
     mod = _reload_client()
-    assert mod._resolve_provider_base_url("xai") == "https://api.x.ai/v1"
-    assert mod._resolve_provider_base_url("deepseek") == "https://api.deepseek.com"
+    assert _base_url(mod, "xai") == "https://api.x.ai/v1"
+    assert _base_url(mod, "deepseek") == "https://api.deepseek.com"
 
 
 def test_client_get_llm_picks_up_env(monkeypatch):

tests/test_openai_compatible_provider.py

@@ -0,0 +1,75 @@
+"""Generic OpenAI-compatible provider (vLLM / LM Studio / llama.cpp / relays).
+
+Verifies the user-supplied base_url is required and honored, the key is optional
+(keyless local default), Chat Completions (not the Responses API) is used, any
+model name is accepted, and the env backend URL precedence (#978).
+"""
+import os
+
+import pytest
+
+from tradingagents.llm_clients.api_key_env import get_api_key_env
+from tradingagents.llm_clients.factory import create_llm_client
+from tradingagents.llm_clients.validators import validate_model
+
+# Note: assert by class NAME, not isinstance — other tests reload the
+# openai_client module, which would otherwise create a second class identity.
+
+
+@pytest.mark.unit
+def test_factory_routes_to_openai_client():
+    client = create_llm_client(
+        provider="openai_compatible", model="my-model", base_url="http://localhost:8000/v1"
+    )
+    assert type(client).__name__ == "OpenAIClient"
+
+
+@pytest.mark.unit
+def test_base_url_required(monkeypatch):
+    monkeypatch.delenv("OPENAI_COMPATIBLE_API_KEY", raising=False)
+    with pytest.raises(ValueError, match="requires a base_url"):
+        create_llm_client(provider="openai_compatible", model="m").get_llm()
+
+
+@pytest.mark.unit
+def test_keyless_local_uses_placeholder_and_chat_completions(monkeypatch):
+    monkeypatch.delenv("OPENAI_COMPATIBLE_API_KEY", raising=False)
+    llm = create_llm_client(
+        provider="openai_compatible", model="qwen2.5", base_url="http://localhost:8000/v1"
+    ).get_llm()
+    assert type(llm).__name__ == "NormalizedChatOpenAI"
+    assert str(llm.openai_api_base) == "http://localhost:8000/v1"
+    # keyless local servers: a placeholder key is sent
+    key = llm.openai_api_key.get_secret_value() if hasattr(llm.openai_api_key, "get_secret_value") else llm.openai_api_key
+    assert key == "EMPTY"
+    # must use Chat Completions, not OpenAI's Responses API
+    assert getattr(llm, "use_responses_api", False) in (False, None)
+
+
+@pytest.mark.unit
+def test_optional_key_from_env(monkeypatch):
+    monkeypatch.setenv("OPENAI_COMPATIBLE_API_KEY", "sk-relay-123")
+    llm = create_llm_client(
+        provider="openai_compatible", model="m", base_url="https://relay.example/v1"
+    ).get_llm()
+    key = llm.openai_api_key.get_secret_value() if hasattr(llm.openai_api_key, "get_secret_value") else llm.openai_api_key
+    assert key == "sk-relay-123"
+
+
+@pytest.mark.unit
+def test_any_model_accepted_no_forced_key():
+    assert validate_model("openai_compatible", "literally-anything") is True
+    # The key env exists (read for keyed relays) but the provider is marked
+    # key-optional, so the CLI never forces a prompt and keyless servers work.
+    assert get_api_key_env("openai_compatible") == "OPENAI_COMPATIBLE_API_KEY"
+    from tradingagents.llm_clients.openai_client import OPENAI_COMPATIBLE_PROVIDERS
+    assert OPENAI_COMPATIBLE_PROVIDERS["openai_compatible"].key_optional is True
+
+
+@pytest.mark.unit
+def test_env_backend_url_precedence():
+    # #978: explicit env URL wins over the menu/default regardless of provider source.
+    from cli.utils import resolve_backend_url
+    assert resolve_backend_url("openai", "https://api.openai.com/v1", env_url="http://proxy/v1") == "http://proxy/v1"
+    assert resolve_backend_url("openai", "https://api.openai.com/v1", env_url=None) == "https://api.openai.com/v1"
+    assert resolve_backend_url("deepseek", None, None) == "https://api.deepseek.com"

tests/test_provider_registry.py

@@ -0,0 +1,55 @@
+"""The OpenAI-compatible provider registry is the single source of truth for the
+family; this guards each provider's resolved config (base URL, subclass, auth,
+Responses API) so a future edit can't silently break one.
+"""
+import pytest
+
+from tradingagents.llm_clients.openai_client import (
+    OPENAI_COMPATIBLE_PROVIDERS,
+    DeepSeekChatOpenAI,
+    MinimaxChatOpenAI,
+    NormalizedChatOpenAI,
+    is_openai_compatible,
+)
+
+
+@pytest.mark.unit
+def test_registry_membership():
+    assert is_openai_compatible("openai")
+    assert is_openai_compatible("openai_compatible")  # the generic endpoint
+    # native (different API) clients are intentionally NOT in the registry
+    assert not is_openai_compatible("anthropic")
+    assert not is_openai_compatible("google")
+    assert not is_openai_compatible("azure")
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("provider,base_url,chat_class,responses", [
+    ("openai", None, NormalizedChatOpenAI, True),
+    ("xai", "https://api.x.ai/v1", NormalizedChatOpenAI, False),
+    ("deepseek", "https://api.deepseek.com", DeepSeekChatOpenAI, False),
+    ("qwen", "https://dashscope-intl.aliyuncs.com/compatible-mode/v1", NormalizedChatOpenAI, False),
+    ("qwen-cn", "https://dashscope.aliyuncs.com/compatible-mode/v1", NormalizedChatOpenAI, False),
+    ("glm", "https://api.z.ai/api/paas/v4/", NormalizedChatOpenAI, False),
+    ("glm-cn", "https://open.bigmodel.cn/api/paas/v4/", NormalizedChatOpenAI, False),
+    ("minimax", "https://api.minimax.io/v1", MinimaxChatOpenAI, False),
+    ("minimax-cn", "https://api.minimaxi.com/v1", MinimaxChatOpenAI, False),
+    ("openrouter", "https://openrouter.ai/api/v1", NormalizedChatOpenAI, False),
+    ("ollama", "http://localhost:11434/v1", NormalizedChatOpenAI, False),
+])
+def test_registry_spec(provider, base_url, chat_class, responses):
+    spec = OPENAI_COMPATIBLE_PROVIDERS[provider]
+    assert spec.base_url == base_url
+    assert spec.chat_class is chat_class
+    assert spec.use_responses_api is responses
+
+
+@pytest.mark.unit
+def test_key_optionality():
+    # Local/generic endpoints are key-optional; hosted APIs require a key.
+    assert OPENAI_COMPATIBLE_PROVIDERS["ollama"].key_optional is True
+    assert OPENAI_COMPATIBLE_PROVIDERS["openai_compatible"].key_optional is True
+    assert OPENAI_COMPATIBLE_PROVIDERS["openai_compatible"].require_base_url is True
+    assert OPENAI_COMPATIBLE_PROVIDERS["xai"].key_optional is False
+    # OLLAMA_BASE_URL is the only base-URL env override.
+    assert OPENAI_COMPATIBLE_PROVIDERS["ollama"].base_url_env == "OLLAMA_BASE_URL"