fix: URL-based auth for third-party Anthropic endpoints + CI test fixes (#4148)

* fix(tests): mock sys.stdin.isatty for cmd_model TTY guard

* fix(tests): update camofox snapshot format + trajectory compressor mock path

- test_browser_camofox: mock response now uses snapshot format (accessibility tree)
- test_trajectory_compressor: mock _get_async_client instead of setting async_client directly

* fix: URL-based auth detection for third-party Anthropic endpoints + test fixes

Reverts the key-prefix approach from #4093 which broke JWT and managed
key OAuth detection. Instead, detects third-party endpoints by URL:
if base_url is set and isn't anthropic.com, it's a proxy (Azure AI
Foundry, AWS Bedrock, etc.) that uses x-api-key regardless of key format.

Auth decision chain is now:
1. _requires_bearer_auth(url) → MiniMax → Bearer
2. _is_third_party_anthropic_endpoint(url) → Azure/Bedrock → x-api-key
3. _is_oauth_token(key) → OAuth on direct Anthropic → Bearer
4. else → x-api-key

Also includes test fixes from PR #4051 by @erosika:
- Mock sys.stdin.isatty for cmd_model TTY guard
- Update camofox snapshot format mock
- Fix trajectory compressor async client mock path

---------

Co-authored-by: Erosika <eri@plasticlabs.ai>

agent/anthropic_adapter.py

@@ -152,20 +152,31 @@ def _is_oauth_token(key: str) -> bool:
 
     Regular API keys start with 'sk-ant-api'. Everything else (setup-tokens
     starting with 'sk-ant-oat', managed keys, JWTs, etc.) needs Bearer auth.
-    Azure AI Foundry keys (non sk-ant- prefixed) should use x-api-key, not Bearer.
     """
     if not key:
         return False
     # Regular Console API keys use x-api-key header
     if key.startswith("sk-ant-api"):
         return False
-    # Azure AI Foundry keys don't start with sk-ant- at all — treat as regular API key
+    # Everything else (setup-tokens, managed keys, JWTs) uses Bearer auth
-    if not key.startswith("sk-ant-"):
-        return False
-    # Everything else (setup-tokens sk-ant-oat, managed keys, JWTs) uses Bearer auth
     return True
 
 
+def _is_third_party_anthropic_endpoint(base_url: str | None) -> bool:
+    """Return True for non-Anthropic endpoints using the Anthropic Messages API.
+
+    Third-party proxies (Azure AI Foundry, AWS Bedrock, self-hosted) authenticate
+    with their own API keys via x-api-key, not Anthropic OAuth tokens. OAuth
+    detection should be skipped for these endpoints.
+    """
+    if not base_url:
+        return False  # No base_url = direct Anthropic API
+    normalized = base_url.rstrip("/").lower()
+    if "anthropic.com" in normalized:
+        return False  # Direct Anthropic API — OAuth applies
+    return True  # Any other endpoint is a third-party proxy
+
+
 def _requires_bearer_auth(base_url: str | None) -> bool:
     """Return True for Anthropic-compatible providers that require Bearer auth.
 
@@ -209,6 +220,14 @@ def build_anthropic_client(api_key: str, base_url: str = None):
         kwargs["auth_token"] = api_key
         if _COMMON_BETAS:
             kwargs["default_headers"] = {"anthropic-beta": ",".join(_COMMON_BETAS)}
+    elif _is_third_party_anthropic_endpoint(base_url):
+        # Third-party proxies (Azure AI Foundry, AWS Bedrock, etc.) use their
+        # own API keys with x-api-key auth. Skip OAuth detection — their keys
+        # don't follow Anthropic's sk-ant-* prefix convention and would be
+        # misclassified as OAuth tokens.
+        kwargs["api_key"] = api_key
+        if _COMMON_BETAS:
+            kwargs["default_headers"] = {"anthropic-beta": ",".join(_COMMON_BETAS)}
     elif _is_oauth_token(api_key):
         # OAuth access token / setup-token → Bearer auth + Claude Code identity.
         # Anthropic routes OAuth requests based on user-agent and headers;

tests/agent/test_auxiliary_client.py

@@ -310,7 +310,7 @@ class TestExpiredCodexFallback:
     def test_hermes_oauth_file_sets_oauth_flag(self, monkeypatch):
         """OAuth-style tokens should get is_oauth=True (token is not sk-ant-api-*)."""
         # Mock resolve_anthropic_token to return an OAuth-style token
-        with patch("agent.anthropic_adapter.resolve_anthropic_token", return_value="sk-ant-oat01-hermes-oauth-test"), \
+        with patch("agent.anthropic_adapter.resolve_anthropic_token", return_value="hermes-oauth-jwt-token"), \
              patch("agent.anthropic_adapter.build_anthropic_client") as mock_build:
             mock_build.return_value = MagicMock()
             from agent.auxiliary_client import _try_anthropic, AnthropicAuxiliaryClient
@@ -364,7 +364,7 @@ class TestExpiredCodexFallback:
 
     def test_claude_code_oauth_env_sets_flag(self, monkeypatch):
         """CLAUDE_CODE_OAUTH_TOKEN env var should get is_oauth=True."""
-        monkeypatch.setenv("CLAUDE_CODE_OAUTH_TOKEN", "sk-ant-oat01-cc-oauth-test")
+        monkeypatch.setenv("CLAUDE_CODE_OAUTH_TOKEN", "cc-oauth-token-test")
         monkeypatch.delenv("ANTHROPIC_TOKEN", raising=False)
         with patch("agent.anthropic_adapter.build_anthropic_client") as mock_build:
             mock_build.return_value = MagicMock()

tests/test_cli_provider_resolution.py

@@ -424,6 +424,7 @@ def test_cmd_model_falls_back_to_auto_on_invalid_provider(monkeypatch, capsys):
 
     monkeypatch.setattr("hermes_cli.auth.resolve_provider", _resolve_provider)
     monkeypatch.setattr(hermes_main, "_prompt_provider_choice", lambda choices: len(choices) - 1)
+    monkeypatch.setattr("sys.stdin", type("FakeTTY", (), {"isatty": lambda self: True})())
 
     hermes_main.cmd_model(SimpleNamespace())
     output = capsys.readouterr().out

tests/test_trajectory_compressor.py

@@ -405,12 +405,13 @@ class TestGenerateSummary:
     @pytest.mark.asyncio
     async def test_generate_summary_async_handles_none_content(self):
         tc = _make_compressor()
-        tc.async_client = MagicMock()
+        mock_client = MagicMock()
-        tc.async_client.chat.completions.create = AsyncMock(
+        mock_client.chat.completions.create = AsyncMock(
             return_value=SimpleNamespace(
                 choices=[SimpleNamespace(message=SimpleNamespace(content=None))]
             )
         )
+        tc._get_async_client = MagicMock(return_value=mock_client)
         metrics = TrajectoryMetrics()
 
         summary = await tc._generate_summary_async("Turn content", metrics)

tests/tools/test_browser_camofox.py

@@ -235,8 +235,13 @@ class TestCamofoxGetImages:
         mock_post.return_value = _mock_response(json_data={"tabId": "tab10", "url": "https://x.com"})
         camofox_navigate("https://x.com", task_id="t10")
 
+        # camofox_get_images parses images from the accessibility tree snapshot
+        snapshot_text = (
+            '- img "Logo"\n'
+            '  /url: https://x.com/img.png\n'
+        )
         mock_get.return_value = _mock_response(json_data={
-            "images": [{"src": "https://x.com/img.png", "alt": "Logo"}],
+            "snapshot": snapshot_text,
         })
         result = json.loads(camofox_get_images(task_id="t10"))
         assert result["success"] is True