fix(model_metadata): respect context_length from custom_providers config with scoping

agent/model_metadata.py

@@ -939,6 +939,42 @@ def get_model_context_length(
     if config_context_length is not None and isinstance(config_context_length, int) and config_context_length > 0:
         return config_context_length
 
+    # 0a. Config-driven overrides from custom_providers[].models[].context_length.
+    # When provider/base_url is known, scope the lookup to the matching custom
+    # provider entry to avoid collisions between identically-named models on
+    # different endpoints. When unknown, allow matching any custom provider.
+    try:
+        from hermes_cli.config import load_config
+        _cfg = load_config()
+        _custom_providers = _cfg.get("custom_providers", []) if isinstance(_cfg, dict) else []
+        if isinstance(_custom_providers, list):
+            _normalized_base_url = base_url.rstrip("/") if isinstance(base_url, str) and base_url else None
+            _active_provider = str(provider).strip().lower() if isinstance(provider, str) and provider.strip() else None
+            _valid_entries = [cp for cp in _custom_providers if isinstance(cp, dict)]
+            for cp in _valid_entries:
+                _cp_base = str(cp.get("base_url", "")).strip().rstrip("/")
+                _cp_name = str(cp.get("name", "")).strip().lower()
+
+                if _normalized_base_url is not None and _cp_base:
+                    if _cp_base != _normalized_base_url:
+                        continue
+                elif _active_provider is not None and _cp_name:
+                    if _cp_name != _active_provider:
+                        continue
+                elif len(_valid_entries) > 1:
+                    # Ambiguous: skip unscoped entries when multiple providers exist
+                    continue
+
+                _models = cp.get("models", {})
+                if isinstance(_models, dict):
+                    _model_entry = _models.get(model, {})
+                    if isinstance(_model_entry, dict):
+                        _ctx = _model_entry.get("context_length")
+                        if isinstance(_ctx, int) and _ctx > 0:
+                            return _ctx
+    except Exception:
+        pass
+
     # Normalise provider-prefixed model names (e.g. "local:model-name" →
     # "model-name") so cache lookups and server queries use the bare ID that
     # local servers actually know about.  Ollama "model:tag" colons are preserved.

tests/agent/test_model_metadata.py

@@ -709,3 +709,100 @@ def test_special_chars_in_model_name(self, tmp_path):
         with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
             save_context_length(model, url, 200000)
             assert get_cached_context_length(model, url) == 200000
+
+
+class TestCustomProvidersContextLength:
+    """Tests for config-driven context_length overrides in custom_providers."""
+
+    @patch("hermes_cli.config.load_config")
+    def test_match_by_provider_name(self, mock_load_config):
+        mock_load_config.return_value = {
+            "custom_providers": [
+                {
+                    "name": "zai-customize",
+                    "base_url": "https://open.bigmodel.cn/api/coding/paas/v4",
+                    "models": {
+                        "glm-5.1": {"context_length": 200000},
+                    },
+                }
+            ]
+        }
+        result = get_model_context_length("glm-5.1", provider="zai-customize")
+        assert result == 200000
+
+    @patch("hermes_cli.config.load_config")
+    def test_match_by_base_url(self, mock_load_config):
+        mock_load_config.return_value = {
+            "custom_providers": [
+                {
+                    "name": "zai-customize",
+                    "base_url": "https://open.bigmodel.cn/api/coding/paas/v4",
+                    "models": {
+                        "glm-5.1": {"context_length": 200000},
+                    },
+                }
+            ]
+        }
+        result = get_model_context_length(
+            "glm-5.1", base_url="https://open.bigmodel.cn/api/coding/paas/v4"
+        )
+        assert result == 200000
+
+    @patch("hermes_cli.config.load_config")
+    def test_unmatched_provider_is_ignored(self, mock_load_config):
+        """A model name in a different custom provider must not leak across."""
+        mock_load_config.return_value = {
+            "custom_providers": [
+                {
+                    "name": "zai-customize",
+                    "base_url": "https://open.bigmodel.cn/api/coding/paas/v4",
+                    "models": {
+                        "glm-5.1": {"context_length": 200000},
+                    },
+                },
+                {
+                    "name": "other-provider",
+                    "base_url": "https://other.example.com/v1",
+                    "models": {
+                        "glm-5.1": {"context_length": 128000},
+                    },
+                },
+            ]
+        }
+        result = get_model_context_length("glm-5.1", provider="zai-customize")
+        assert result == 200000
+
+    @patch("hermes_cli.config.load_config")
+    def test_single_provider_fallback_when_no_scope(self, mock_load_config):
+        """With only one custom provider, allow matching even without provider/base_url."""
+        mock_load_config.return_value = {
+            "custom_providers": [
+                {
+                    "name": "zai-customize",
+                    "models": {
+                        "glm-5.1": {"context_length": 200000},
+                    },
+                }
+            ]
+        }
+        result = get_model_context_length("glm-5.1")
+        assert result == 200000
+
+    @patch("hermes_cli.config.load_config")
+    def test_ambiguous_multiple_providers_skipped_without_scope(self, mock_load_config):
+        """When multiple providers exist and no scope is given, skip to avoid collisions."""
+        mock_load_config.return_value = {
+            "custom_providers": [
+                {
+                    "name": "zai-customize",
+                    "models": {"glm-5.1": {"context_length": 200000}},
+                },
+                {
+                    "name": "other-provider",
+                    "models": {"glm-5.1": {"context_length": 128000}},
+                },
+            ]
+        }
+        # Must NOT pick either custom provider value because scope is ambiguous
+        result = get_model_context_length("glm-5.1")
+        assert result not in (200000, 128000)