test(compression): cover real init feasibility override

run_agent.py

@@ -1271,7 +1271,10 @@ class AIAgent:
             _agent_cfg = _load_agent_config()
         except Exception:
             _agent_cfg = {}
-        self._config = _agent_cfg  # stored for later use (e.g. compression feasibility check)
+        # Cache only the derived auxiliary compression context override that is
+        # needed later by the startup feasibility check.  Avoid exposing a
+        # broad pseudo-public config object on the agent instance.
+        self._aux_compression_context_length_config = None
 
         # Persistent memory (MEMORY.md + USER.md) -- loaded from disk
         self._memory_store = None
@@ -1402,6 +1405,24 @@ class AIAgent:
         compression_target_ratio = float(_compression_cfg.get("target_ratio", 0.20))
         compression_protect_last = int(_compression_cfg.get("protect_last_n", 20))
 
+        # Read optional explicit context_length override for the auxiliary
+        # compression model. Custom endpoints often cannot report this via
+        # /models, so the startup feasibility check needs the config hint.
+        try:
+            _aux_cfg = _agent_cfg.get("auxiliary", {}).get("compression", {})
+        except Exception:
+            _aux_cfg = {}
+        if isinstance(_aux_cfg, dict):
+            _aux_context_config = _aux_cfg.get("context_length")
+        else:
+            _aux_context_config = None
+        if _aux_context_config is not None:
+            try:
+                _aux_context_config = int(_aux_context_config)
+            except (TypeError, ValueError):
+                _aux_context_config = None
+        self._aux_compression_context_length_config = _aux_context_config
+
         # Read explicit context_length override from model config
         _model_cfg = _agent_cfg.get("model", {})
         if isinstance(_model_cfg, dict):
@@ -1999,24 +2020,11 @@ class AIAgent:
             aux_base_url = str(getattr(client, "base_url", ""))
             aux_api_key = str(getattr(client, "api_key", ""))
 
-            # Read user-configured context_length for the compression model.
-            # Custom endpoints often don't support /models API queries so
-            # get_model_context_length() falls through to the 128K default,
-            # ignoring the explicit config value.  Pass it as the highest-
-            # priority hint so the configured value is always respected.
-            _aux_cfg = (self._config or {}).get("auxiliary", {}).get("compression", {})
-            _aux_context_config = _aux_cfg.get("context_length") if isinstance(_aux_cfg, dict) else None
-            if _aux_context_config is not None:
-                try:
-                    _aux_context_config = int(_aux_context_config)
-                except (TypeError, ValueError):
-                    _aux_context_config = None
-
             aux_context = get_model_context_length(
                 aux_model,
                 base_url=aux_base_url,
                 api_key=aux_api_key,
-                config_context_length=_aux_context_config,
+                config_context_length=getattr(self, "_aux_compression_context_length_config", None),
             )
 
             threshold = self.context_compressor.threshold_tokens

tests/run_agent/test_compression_feasibility.py

@@ -38,7 +38,7 @@ def _make_agent(
     agent.status_callback = None
     agent.tool_progress_callback = None
     agent._compression_warning = None
-    agent._config = None
+    agent._aux_compression_context_length_config = None
 
     compressor = MagicMock(spec=ContextCompressor)
     compressor.context_length = main_context
@@ -138,13 +138,7 @@ def test_feasibility_check_passes_config_context_length(mock_get_client, mock_ct
     get_model_context_length so custom endpoints that lack /models still
     report the correct context window (fixes #8499)."""
     agent = _make_agent(main_context=200_000, threshold_percent=0.85)
-    agent._config = {
-        "auxiliary": {
-            "compression": {
-                "context_length": 1_000_000,
-            },
-        },
-    }
+    agent._aux_compression_context_length_config = 1_000_000
     mock_client = MagicMock()
     mock_client.base_url = "http://custom-endpoint:8080/v1"
     mock_client.api_key = "sk-custom"
@@ -166,13 +160,7 @@ def test_feasibility_check_passes_config_context_length(mock_get_client, mock_ct
 def test_feasibility_check_ignores_invalid_context_length(mock_get_client, mock_ctx_len):
     """Non-integer context_length in config is silently ignored."""
     agent = _make_agent(main_context=200_000, threshold_percent=0.50)
-    agent._config = {
-        "auxiliary": {
-            "compression": {
-                "context_length": "not-a-number",
-            },
-        },
-    }
+    agent._aux_compression_context_length_config = None
     mock_client = MagicMock()
     mock_client.base_url = "http://custom:8080/v1"
     mock_client.api_key = "sk-test"
@@ -189,6 +177,58 @@ def test_feasibility_check_ignores_invalid_context_length(mock_get_client, mock_
     )
 
 
+def test_init_feasibility_check_uses_aux_context_override_from_config():
+    """Real AIAgent init should cache and forward auxiliary.compression.context_length."""
+
+    class _StubCompressor:
+        def __init__(self, *args, **kwargs):
+            self.context_length = 200_000
+            self.threshold_tokens = 100_000
+            self.threshold_percent = 0.50
+
+        def get_tool_schemas(self):
+            return []
+
+        def on_session_start(self, *args, **kwargs):
+            return None
+
+    cfg = {
+        "auxiliary": {
+            "compression": {
+                "context_length": 1_000_000,
+            },
+        },
+    }
+    mock_client = MagicMock()
+    mock_client.base_url = "http://custom-endpoint:8080/v1"
+    mock_client.api_key = "sk-custom"
+
+    with (
+        patch("hermes_cli.config.load_config", return_value=cfg),
+        patch("run_agent.get_tool_definitions", return_value=[]),
+        patch("run_agent.check_toolset_requirements", return_value={}),
+        patch("run_agent.OpenAI"),
+        patch("run_agent.ContextCompressor", new=_StubCompressor),
+        patch("agent.auxiliary_client.get_text_auxiliary_client", return_value=(mock_client, "custom/big-model")),
+        patch("agent.model_metadata.get_model_context_length", return_value=1_000_000) as mock_ctx_len,
+    ):
+        agent = AIAgent(
+            api_key="test-key-1234567890",
+            base_url="https://openrouter.ai/api/v1",
+            quiet_mode=True,
+            skip_context_files=True,
+            skip_memory=True,
+        )
+
+    assert agent._aux_compression_context_length_config == 1_000_000
+    mock_ctx_len.assert_called_once_with(
+        "custom/big-model",
+        base_url="http://custom-endpoint:8080/v1",
+        api_key="sk-custom",
+        config_context_length=1_000_000,
+    )
+
+
 @patch("agent.auxiliary_client.get_text_auxiliary_client")
 def test_warns_when_no_auxiliary_provider(mock_get_client):
     """Warning emitted when no auxiliary provider is configured."""