fix(anthropic): ignore stale non-Anthropic base_url across all resolution paths

A config left with `provider: anthropic` but a leftover
`base_url: https://openrouter.ai/api/v1` (e.g. after a provider switch)
would route Anthropic OAuth/setup-token traffic to OpenRouter and 404.

Add `_anthropic_base_url_override_ok()` and gate the three native-Anthropic
resolution branches (pool, explicit, native) on it. The guard honors a
configured `model.base_url` only when it plausibly speaks the Anthropic
Messages protocol — official `*.anthropic.com` / `*.claude.com` hosts, Azure
Foundry endpoints, and `/anthropic`-suffixed or Kimi `/coding` proxies — and
falls back to `https://api.anthropic.com` otherwise. Aggregator URLs like
openrouter.ai / api.openai.com are treated as stale.

Reconstructed from @clovericbot's PR #3661 onto current main: the original
patched one branch with an anthropic-only allow-list, which would have broken
Azure-via-anthropic; widened to all three sites and made Azure/proxy-safe.

hermes_cli/runtime_provider.py

@@ -172,6 +172,43 @@ def _host_derived_api_key(base_url: str) -> str:
     return (_getenv(env_name, "") or "").strip()
 
 
+def _anthropic_base_url_override_ok(base_url: str) -> bool:
+    """Decide whether a configured ``model.base_url`` may back native Anthropic.
+
+    Native ``provider: anthropic`` resolution honors ``model.base_url`` so users
+    can point at Anthropic-compatible endpoints (official Anthropic/Claude hosts,
+    Azure Foundry, MiniMax/Zhipu/LiteLLM-style ``/anthropic`` proxies, Kimi's
+    ``/coding`` route). But a config can carry a *stale* non-Anthropic URL — e.g.
+    ``provider: anthropic`` left with ``base_url: https://openrouter.ai/api/v1``
+    after a provider switch — which would route Anthropic OAuth/setup-token
+    traffic to an OpenAI-compatible aggregator and 404. Ignore those.
+
+    Returns True only when the URL plausibly speaks the Anthropic Messages
+    protocol; otherwise the caller falls back to ``https://api.anthropic.com``.
+    """
+    candidate = (base_url or "").strip()
+    if not candidate:
+        return False
+
+    hostname = (base_url_hostname(candidate) or "").lower()
+    if not hostname:
+        return False
+
+    # Official Anthropic / Claude hosts.
+    if hostname == "api.anthropic.com" or hostname.endswith(".anthropic.com") or hostname.endswith(".claude.com"):
+        return True
+    # Azure Foundry Anthropic endpoints (handled specially downstream).
+    if hostname.endswith(".azure.com"):
+        return True
+    # Anthropic-compatible proxies conventionally expose the native Messages
+    # protocol under a ``/anthropic`` suffix, and Kimi under ``/coding`` — same
+    # signal _detect_api_mode_for_url() uses to pick anthropic_messages.
+    if _detect_api_mode_for_url(candidate) == "anthropic_messages":
+        return True
+    # Bare api.kimi.com without the /coding path is not an Anthropic endpoint.
+    return False
+
+
 def _auto_detect_local_model(base_url: str) -> str:
     """Query a local server for its model name when only one model is loaded."""
     if not base_url:
@@ -344,6 +381,8 @@ def _resolve_runtime_from_pool_entry(
         cfg_base_url = ""
         if cfg_provider == "anthropic":
             cfg_base_url = str(model_cfg.get("base_url") or "").strip().rstrip("/")
+            if not _anthropic_base_url_override_ok(cfg_base_url):
+                cfg_base_url = ""
         base_url = cfg_base_url or base_url or "https://api.anthropic.com"
     elif provider == "openrouter":
         base_url = base_url or OPENROUTER_BASE_URL
@@ -1247,6 +1286,8 @@ def _resolve_explicit_runtime(
         cfg_base_url = ""
         if cfg_provider == "anthropic":
             cfg_base_url = str(model_cfg.get("base_url") or "").strip().rstrip("/")
+            if not _anthropic_base_url_override_ok(cfg_base_url):
+                cfg_base_url = ""
         base_url = explicit_base_url or cfg_base_url or "https://api.anthropic.com"
         api_key = explicit_api_key
         if not api_key:
@@ -1697,6 +1738,8 @@ def resolve_runtime_provider(
         cfg_base_url = ""
         if cfg_provider == "anthropic":
             cfg_base_url = (model_cfg.get("base_url") or "").strip().rstrip("/")
+            if not _anthropic_base_url_override_ok(cfg_base_url):
+                cfg_base_url = ""
         base_url = cfg_base_url or "https://api.anthropic.com"
 
         # For Microsoft Foundry endpoints, use ANTHROPIC_API_KEY directly —

tests/hermes_cli/test_runtime_provider_resolution.py

@@ -76,6 +76,68 @@ def test_resolve_runtime_provider_anthropic_pool_respects_config_base_url(monkey
     assert resolved["base_url"] == "https://proxy.example.com/anthropic"
 
 
+def test_resolve_runtime_provider_anthropic_ignores_stale_aggregator_base_url(monkeypatch):
+    """A leftover OpenRouter base_url under provider: anthropic must not hijack
+    Anthropic OAuth traffic — fall back to the official Anthropic host."""
+
+    class _Entry:
+        access_token = "pool-token"
+        source = "manual"
+        base_url = "https://api.anthropic.com"
+
+    class _Pool:
+        def has_credentials(self):
+            return True
+
+        def select(self):
+            return _Entry()
+
+    monkeypatch.setattr(rp, "resolve_provider", lambda *a, **k: "anthropic")
+    monkeypatch.setattr(rp, "load_pool", lambda provider: _Pool())
+
+    for stale in (
+        "https://openrouter.ai/api/v1",
+        "https://api.openai.com/v1",
+    ):
+        monkeypatch.setattr(
+            rp,
+            "_get_model_config",
+            lambda stale=stale: {"provider": "anthropic", "base_url": stale},
+        )
+        resolved = rp.resolve_runtime_provider(requested="anthropic")
+        assert resolved["provider"] == "anthropic"
+        assert resolved["api_mode"] == "anthropic_messages"
+        assert resolved["base_url"] == "https://api.anthropic.com", stale
+
+
+def test_resolve_runtime_provider_anthropic_keeps_azure_base_url(monkeypatch):
+    """Azure Foundry Anthropic endpoints are not anthropic.com hosts but are a
+    legitimate override — they must survive the stale-URL guard."""
+
+    class _Entry:
+        access_token = "pool-token"
+        source = "manual"
+        base_url = "https://api.anthropic.com"
+
+    class _Pool:
+        def has_credentials(self):
+            return True
+
+        def select(self):
+            return _Entry()
+
+    monkeypatch.setattr(rp, "resolve_provider", lambda *a, **k: "anthropic")
+    monkeypatch.setattr(rp, "load_pool", lambda provider: _Pool())
+    monkeypatch.setattr(
+        rp,
+        "_get_model_config",
+        lambda: {"provider": "anthropic", "base_url": "https://myhost.azure.com/anthropic"},
+    )
+
+    resolved = rp.resolve_runtime_provider(requested="anthropic")
+    assert resolved["base_url"] == "https://myhost.azure.com/anthropic"
+
+
 def test_resolve_runtime_provider_anthropic_explicit_override_skips_pool(monkeypatch):
     def _unexpected_pool(provider):
         raise AssertionError(f"load_pool should not be called for {provider}")