diff --git a/agent/agent_init.py b/agent/agent_init.py
index 210743f92ac8..6055b8c0ccbc 100644
--- a/agent/agent_init.py
+++ b/agent/agent_init.py
@@ -1757,8 +1757,9 @@ def init_agent(
             )
             _config_context_length = None
 
-    # Resolve custom_providers list once for reuse below (startup
-    # context-length override and plugin context-engine init).
+    # Resolve custom_providers once before route-scoping a global context pin:
+    # a named custom provider may keep its base URL only in this list rather
+    # than repeating it under ``model``.
     try:
         from hermes_cli.config import get_compatible_custom_providers
         _custom_providers = get_compatible_custom_providers(_agent_cfg)
@@ -1767,6 +1768,79 @@ def init_agent(
         if not isinstance(_custom_providers, list):
             _custom_providers = []
 
+    # ``model.context_length`` describes the configured default model. A
+    # process launched directly with ``--model`` / ``-m`` has already replaced
+    # ``agent.model`` before this initializer loads config, so carrying the
+    # default model's explicit window into that different runtime is stale. The
+    # live switch/fallback paths already clear this override; keep direct-start
+    # overrides consistent with them and let provider metadata resolve the
+    # active model's window instead.
+    if _config_context_length is not None and isinstance(_model_cfg, dict):
+        _configured_default_model = str(_model_cfg.get("default") or "").strip()
+        _configured_default_runtime_model = _configured_default_model
+        _active_runtime_model = agent.model
+        if _configured_default_model:
+            try:
+                from hermes_cli.model_normalize import normalize_model_for_provider
+
+                _configured_default_runtime_model = normalize_model_for_provider(
+                    _configured_default_model, agent.provider
+                )
+                _active_runtime_model = normalize_model_for_provider(
+                    agent.model, agent.provider
+                )
+            except Exception:
+                pass
+        _configured_provider = str(_model_cfg.get("provider") or "").strip()
+        _configured_base_url = str(_model_cfg.get("base_url") or "").rstrip("/")
+        if not _configured_base_url and _configured_provider.lower().startswith("custom:"):
+            _configured_custom_name = _configured_provider.split(":", 1)[1].lower()
+            for _provider_entry in _custom_providers:
+                if not isinstance(_provider_entry, dict):
+                    continue
+                if str(_provider_entry.get("name") or "").strip().lower() != _configured_custom_name:
+                    continue
+                _configured_base_url = str(
+                    _provider_entry.get("base_url") or ""
+                ).rstrip("/")
+                break
+        _active_base_url = str(agent.base_url or "").rstrip("/")
+        _route_mismatch = bool(
+            _configured_base_url
+            and _active_base_url
+            and _configured_base_url != _active_base_url
+        )
+        if not _configured_base_url:
+            _active_provider = str(agent.provider or "").strip()
+            try:
+                from hermes_cli.models import normalize_provider
+
+                _configured_provider = normalize_provider(_configured_provider)
+                _active_provider = normalize_provider(_active_provider)
+            except Exception:
+                _configured_provider = _configured_provider.lower()
+                _active_provider = _active_provider.lower()
+            _route_mismatch = bool(
+                _configured_provider
+                and _active_provider
+                and _configured_provider != _active_provider
+            )
+        _model_mismatch = bool(
+            _configured_default_runtime_model
+            and _configured_default_runtime_model != _active_runtime_model
+        )
+        if _model_mismatch or _route_mismatch:
+            _ra().logger.debug(
+                "Ignoring model.context_length=%s for startup runtime %s at %s "
+                "(configured default is %s at %s)",
+                _config_context_length,
+                agent.model,
+                _active_base_url or agent.provider,
+                _configured_default_model,
+                _configured_base_url or _model_cfg.get("provider"),
+            )
+            _config_context_length = None
+
     # Store for reuse by _check_compression_model_feasibility (auxiliary
     # compression model context-length detection needs the same list).
     agent._custom_providers = _custom_providers
diff --git a/agent/conversation_compression.py b/agent/conversation_compression.py
index dd7b75796b5c..01f882be2ee7 100644
--- a/agent/conversation_compression.py
+++ b/agent/conversation_compression.py
@@ -436,6 +436,19 @@ def check_compression_model_feasibility(agent: Any) -> None:
             old_threshold = threshold
             new_threshold = aux_context
             agent.context_compressor.threshold_tokens = new_threshold
+            # ``tail_token_budget`` is derived from the trigger threshold, not
+            # directly from the model window. Keep it in lockstep with this
+            # just-in-time correction exactly as ContextCompressor.update_model()
+            # does. Leaving the old budget behind can make the tail's 1.5x soft
+            # ceiling wider than the lowered trigger, so compression preserves
+            # nearly the entire request and repeatedly re-fires.
+            summary_target_ratio = getattr(
+                agent.context_compressor, "summary_target_ratio", None
+            )
+            if isinstance(summary_target_ratio, (int, float)):
+                agent.context_compressor.tail_token_budget = int(
+                    new_threshold * summary_target_ratio
+                )
             # Keep threshold_percent in sync so future main-model
             # context_length changes (update_model) re-derive from a
             # sensible number rather than the original too-high value.
diff --git a/agent/conversation_loop.py b/agent/conversation_loop.py
index 501e49b54d55..517c9d86ed7e 100644
--- a/agent/conversation_loop.py
+++ b/agent/conversation_loop.py
@@ -33,6 +33,7 @@ from agent.display import KawaiiSpinner
 from agent.error_classifier import FailoverReason, classify_api_error
 from agent.iteration_budget import IterationBudget
 from agent.turn_context import (
+    _compression_warrants_another_preflight_pass,
     build_turn_context,
     compose_user_api_content,
     reanchor_current_turn_user_idx,
@@ -684,6 +685,8 @@ def run_conversation(
     truncated_tool_call_retries = 0
     truncated_response_parts: List[str] = []
     compression_attempts = 0
+    _last_preflight_pressure: Optional[int] = None
+    _preflight_compression_blocked = _ctx.preflight_compression_blocked
     _turn_exit_reason = "unknown"  # Diagnostic: why the loop ended
     # Last composed answer intentionally held back by a verification gate. If
     # that continuation consumes the remaining budget, this is the best
@@ -1125,6 +1128,37 @@ def run_conversation(
         # LLM cooldown + anti-thrash guards (#11529). compression_attempts is a
         # hard per-turn backstop shared with the overflow error handlers.
         _compressor = agent.context_compressor
+        _preflight_threshold = int(
+            getattr(_compressor, "threshold_tokens", 0) or 0
+        )
+        # A previous mid-turn preflight pass deliberately continued the loop so
+        # API-only context and all sanitization could be rebuilt. Compare that
+        # fully assembled request with the fully assembled request that caused
+        # the pass. Raw ``messages`` are not equivalent here: they omit
+        # api_content/plugin injections, prefills, MoA context, and ephemeral
+        # system text.
+        _previous_preflight_pressure = _last_preflight_pressure
+        _last_preflight_pressure = None
+        if (
+            _previous_preflight_pressure is not None
+            and request_pressure_tokens >= _preflight_threshold
+            and not _compression_warrants_another_preflight_pass(
+                _previous_preflight_pressure,
+                request_pressure_tokens,
+                _preflight_threshold,
+            )
+        ):
+            # Stop proactive retries for this turn without consuming the
+            # shared overflow-recovery budget. If the provider proves the
+            # request truly does not fit, its error handler may still compact
+            # with that stronger signal.
+            _preflight_compression_blocked = True
+            logger.warning(
+                "Pre-API compression made insufficient progress: ~%s -> "
+                "~%s request tokens; skipping additional preflight passes",
+                f"{_previous_preflight_pressure:,}",
+                f"{request_pressure_tokens:,}",
+            )
         _defer_preflight = getattr(
             _compressor, "should_defer_preflight_to_real_usage", lambda _t: False
         )
@@ -1135,6 +1169,7 @@ def run_conversation(
             agent.compression_enabled
             and len(messages) > 1
             and compression_attempts < 3
+            and not _preflight_compression_blocked
             and not _defer_preflight(request_pressure_tokens)
             and not _compression_cooldown
             and _compressor.should_compress(request_pressure_tokens)
@@ -1153,6 +1188,7 @@ def run_conversation(
                 f"📦 Pre-API compression: ~{request_pressure_tokens:,} tokens "
                 f"near the context/output limit. Compacting before the next model call."
             )
+            _last_preflight_pressure = request_pressure_tokens
             messages, active_system_prompt = agent._compress_context(
                 messages,
                 system_message,
diff --git a/agent/turn_context.py b/agent/turn_context.py
index 8807407278c9..89952495b381 100644
--- a/agent/turn_context.py
+++ b/agent/turn_context.py
@@ -210,6 +210,23 @@ def _compression_made_progress(
     return orig_tokens > 0 and new_tokens < orig_tokens * 0.95
 
 
+def _compression_warrants_another_preflight_pass(
+    orig_tokens: int, new_tokens: int, threshold_tokens: int
+) -> bool:
+    """Whether an over-threshold request merits another immediate summary.
+
+    Row-count progress is enough to prove that a compression boundary was real,
+    but not enough to justify another expensive pass before trying the provider.
+    Continue only when the request remains over threshold *and* the previous pass
+    materially reduced its estimated token pressure (>5%).
+    """
+    return (
+        new_tokens >= threshold_tokens
+        and orig_tokens > 0
+        and new_tokens < orig_tokens * 0.95
+    )
+
+
 def _should_run_preflight_estimate(
     messages: List[Dict[str, Any]],
     protect_first_n: int,
@@ -263,6 +280,8 @@ class TurnContext:
     plugin_user_context: str = ""
     # External-memory prefetch result, reused across loop iterations.
     ext_prefetch_cache: str = ""
+    # Turn-start preflight already proved an immediate retry ineffective.
+    preflight_compression_blocked: bool = False
 
 
 def build_turn_context(
@@ -565,6 +584,7 @@ def build_turn_context(
     # See ``_should_run_preflight_estimate`` for the OR semantics that fix
     # issue #27405 (a few very large messages slipping past the count gate).
     _preflight_compressed = False
+    _preflight_compression_blocked = False
     if agent.compression_enabled and _should_run_preflight_estimate(
         messages,
         agent.context_compressor.protect_first_n,
@@ -664,6 +684,7 @@ def build_turn_context(
                 if not _compression_made_progress(
                     _orig_len, len(messages), _orig_tokens, _preflight_tokens
                 ):
+                    _preflight_compression_blocked = True
                     break  # Cannot compress further: neither rows nor tokens moved
                 conversation_history = conversation_history_after_compression(
                     agent, messages
@@ -675,6 +696,19 @@ def build_turn_context(
                 agent._mute_post_response = False
                 if not _compressor.should_compress(_preflight_tokens):
                     break
+                if not _compression_warrants_another_preflight_pass(
+                    _orig_tokens,
+                    _preflight_tokens,
+                    _compressor.threshold_tokens,
+                ):
+                    _preflight_compression_blocked = True
+                    logger.warning(
+                        "Preflight compression made insufficient progress: "
+                        "~%s -> ~%s request tokens; skipping additional passes",
+                        f"{_orig_tokens:,}",
+                        f"{_preflight_tokens:,}",
+                    )
+                    break
 
     if _preflight_compressed:
         # Compression rebuilt the list (tail messages are fresh compaction
@@ -899,4 +933,5 @@ def build_turn_context(
         should_review_memory=should_review_memory,
         plugin_user_context=plugin_user_context,
         ext_prefetch_cache=ext_prefetch_cache,
+        preflight_compression_blocked=_preflight_compression_blocked,
     )
diff --git a/tests/agent/test_compression_progress.py b/tests/agent/test_compression_progress.py
index aff1bd949499..61ec7402e263 100644
--- a/tests/agent/test_compression_progress.py
+++ b/tests/agent/test_compression_progress.py
@@ -14,7 +14,10 @@ progress.
 
 from __future__ import annotations
 
-from agent.turn_context import _compression_made_progress
+from agent.turn_context import (
+    _compression_made_progress,
+    _compression_warrants_another_preflight_pass,
+)
 
 
 class TestCompressionMadeProgress:
@@ -84,3 +87,26 @@ class TestCompressionMadeProgress:
         assert _compression_made_progress(
             orig_len=10, new_len=10, orig_tokens=0, new_tokens=0
         ) is False
+
+
+class TestCompressionWarrantsAnotherPreflightPass:
+    def test_material_reduction_above_threshold_allows_another_pass(self):
+        assert _compression_warrants_another_preflight_pass(
+            orig_tokens=400_000,
+            new_tokens=350_000,
+            threshold_tokens=272_000,
+        ) is True
+
+    def test_marginal_reduction_above_threshold_stops(self):
+        assert _compression_warrants_another_preflight_pass(
+            orig_tokens=350_000,
+            new_tokens=345_000,
+            threshold_tokens=272_000,
+        ) is False
+
+    def test_clearing_threshold_needs_no_additional_pass(self):
+        assert _compression_warrants_another_preflight_pass(
+            orig_tokens=280_000,
+            new_tokens=250_000,
+            threshold_tokens=272_000,
+        ) is False
diff --git a/tests/run_agent/test_413_compression.py b/tests/run_agent/test_413_compression.py
index 302c33bc4649..fc035ac7de6d 100644
--- a/tests/run_agent/test_413_compression.py
+++ b/tests/run_agent/test_413_compression.py
@@ -987,9 +987,17 @@ class TestPreflightCompression:
         with (
             patch("agent.turn_context.estimate_request_tokens_rough", return_value=144_669),
             patch("agent.conversation_loop.estimate_request_tokens_rough", return_value=144_669),
+            patch(
+                "agent.conversation_loop.estimate_messages_tokens_rough",
+                return_value=144_669,
+            ),
             # Compression no-ops (returns input unchanged) — mirrors an aux
             # summary-model timeout where the messages can't be reduced.
-            patch.object(agent, "_compress_context", side_effect=lambda msgs, *a, **k: (msgs, agent._cached_system_prompt)),
+            patch.object(
+                agent,
+                "_compress_context",
+                side_effect=lambda msgs, *a, **k: (msgs, agent._cached_system_prompt),
+            ) as mock_compress,
             patch.object(agent, "_persist_session"),
             patch.object(agent, "_save_trajectory"),
             patch.object(agent, "_cleanup_task_resources"),
@@ -997,6 +1005,10 @@ class TestPreflightCompression:
             result = agent.run_conversation("hello", conversation_history=big_history)
 
         assert result["completed"] is True
+        # A no-op pass cannot become more effective by immediately summarizing
+        # the same request twice more. Proceed to the provider/recovery path
+        # after one attempt instead of spending the full three-pass budget.
+        assert mock_compress.call_count == 1
         # The display token count was revised up to the fresh preflight estimate,
         # not left at the stale 74_400.
         assert agent.context_compressor.last_prompt_tokens == 144_669
@@ -1030,6 +1042,43 @@ class TestPreflightCompression:
         # Smaller estimate must not overwrite the larger tracked value.
         assert agent.context_compressor.last_prompt_tokens == 160_000
 
+    def test_preflight_stops_after_marginal_compression(self, agent):
+        """Do not spend three summary calls removing one row per pass."""
+        agent.compression_enabled = True
+        agent.context_compressor.context_length = 200_000
+        agent.context_compressor.threshold_tokens = 130_000
+
+        big_history = []
+        for i in range(20):
+            big_history.append({"role": "user", "content": f"Message {i} padded text"})
+            big_history.append({"role": "assistant", "content": f"Response {i} padded text"})
+
+        ok_resp = _mock_response(content="After marginal preflight", finish_reason="stop")
+        agent.client.chat.completions.create.side_effect = [ok_resp]
+
+        def _drop_one_row(messages, *_args, **_kwargs):
+            return messages[:-1], agent._cached_system_prompt
+
+        with (
+            patch("agent.turn_context.estimate_request_tokens_rough", return_value=144_669),
+            patch("agent.conversation_loop.estimate_request_tokens_rough", return_value=144_669),
+            patch(
+                "agent.conversation_loop.estimate_messages_tokens_rough",
+                return_value=144_669,
+            ),
+            patch.object(
+                agent, "_compress_context", side_effect=_drop_one_row
+            ) as mock_compress,
+            patch.object(agent, "_persist_session"),
+            patch.object(agent, "_save_trajectory"),
+            patch.object(agent, "_cleanup_task_resources"),
+        ):
+            result = agent.run_conversation("hello", conversation_history=big_history)
+
+        assert result["completed"] is True
+        assert result["final_response"] == "After marginal preflight"
+        assert mock_compress.call_count == 1
+
 
 class TestToolResultPreflightCompression:
     """Compression should trigger when tool results push context past the threshold."""
@@ -1072,6 +1121,59 @@ class TestToolResultPreflightCompression:
         mock_compress.assert_called_once()
         assert result["completed"] is True
 
+    def test_mid_turn_retry_compares_fully_assembled_requests(self, agent):
+        """API-only context must not make marginal compression look effective."""
+        agent.compression_enabled = True
+        agent.context_compressor.context_length = 200_000
+        agent.context_compressor.threshold_tokens = 130_000
+
+        tc = SimpleNamespace(
+            id="tc1", type="function",
+            function=SimpleNamespace(name="web_search", arguments='{"query":"test"}'),
+        )
+        tool_resp = _mock_response(
+            content="",
+            finish_reason="stop",
+            tool_calls=[tc],
+        )
+        ok_resp = _mock_response(
+            content="Done after one compression", finish_reason="stop"
+        )
+        agent.client.chat.completions.create.side_effect = [tool_resp, ok_resp]
+
+        # First provider request is small. The tool result pushes the fully
+        # assembled request over threshold; rebuilding after compression only
+        # trims it from 150K to 148K. Raw-message estimation is much smaller,
+        # which previously made the no-op pass look successful and allowed two
+        # more immediate summaries.
+        assembled_estimates = iter(
+            [1_000, 150_000, 148_000, 148_000, 148_000]
+        )
+
+        with (
+            patch(
+                "agent.conversation_loop.estimate_messages_tokens_rough",
+                side_effect=lambda *_a, **_k: next(assembled_estimates),
+            ),
+            patch("run_agent.handle_function_call", return_value="x" * 100_000),
+            patch.object(
+                agent,
+                "_compress_context",
+                side_effect=lambda msgs, *_a, **_k: (
+                    msgs,
+                    agent._cached_system_prompt,
+                ),
+            ) as mock_compress,
+            patch.object(agent, "_persist_session"),
+            patch.object(agent, "_save_trajectory"),
+            patch.object(agent, "_cleanup_task_resources"),
+        ):
+            result = agent.run_conversation("hello")
+
+        assert result["completed"] is True
+        assert result["final_response"] == "Done after one compression"
+        assert mock_compress.call_count == 1
+
     def test_anthropic_prompt_too_long_safety_net(self, agent):
         """Anthropic 'prompt is too long' error triggers compression as safety net."""
         err_400 = Exception(
diff --git a/tests/run_agent/test_compression_feasibility.py b/tests/run_agent/test_compression_feasibility.py
index 9bd5fd9faf25..f07cf8607b40 100644
--- a/tests/run_agent/test_compression_feasibility.py
+++ b/tests/run_agent/test_compression_feasibility.py
@@ -57,6 +57,10 @@ def _make_agent(
     compressor = MagicMock(spec=ContextCompressor)
     compressor.context_length = main_context
     compressor.threshold_tokens = int(main_context * threshold_percent)
+    compressor.summary_target_ratio = 0.20
+    compressor.tail_token_budget = int(
+        compressor.threshold_tokens * compressor.summary_target_ratio
+    )
     agent.context_compressor = compressor
 
     return agent
@@ -96,6 +100,11 @@ def test_auto_corrects_threshold_when_aux_context_below_threshold(mock_get_clien
     assert agent._compression_warning is not None
     # Threshold on the live compressor was actually lowered to aux_context.
     assert agent.context_compressor.threshold_tokens == 80_000
+    # Every threshold-derived budget must move with it. Keeping the original
+    # 20K tail here would protect 25% of the lowered threshold instead of the
+    # configured 20%, and larger real-world mismatches can make the tail's 1.5x
+    # soft ceiling wider than the entire compression trigger.
+    assert agent.context_compressor.tail_token_budget == 16_000
 
 
 @patch("agent.model_metadata.get_model_context_length", return_value=32_768)
diff --git a/tests/run_agent/test_switch_model_context.py b/tests/run_agent/test_switch_model_context.py
index c925a508915d..33893c68fdff 100644
--- a/tests/run_agent/test_switch_model_context.py
+++ b/tests/run_agent/test_switch_model_context.py
@@ -6,6 +6,41 @@ from run_agent import AIAgent
 from agent.context_compressor import ContextCompressor
 
 
+class _StubStartupCompressor:
+    def __init__(self, *args, **kwargs):
+        self.context_length = kwargs.get("config_context_length") or 272_000
+        self.config_context_length = kwargs.get("config_context_length")
+        self.threshold_tokens = int(self.context_length * 0.95)
+        self.threshold_percent = 0.95
+
+    def get_tool_schemas(self):
+        return []
+
+    def on_session_start(self, *args, **kwargs):
+        return None
+
+
+def _make_direct_start_agent(
+    cfg: dict, *, model: str, provider: str, base_url: str
+) -> AIAgent:
+    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("agent.agent_init.ContextCompressor", new=_StubStartupCompressor),
+    ):
+        return AIAgent(
+            model=model,
+            provider=provider,
+            api_key="fake-test-token",
+            base_url=base_url,
+            quiet_mode=True,
+            skip_context_files=True,
+            skip_memory=True,
+        )
+
+
 def _make_agent_with_compressor(config_context_length=None) -> AIAgent:
     """Build a minimal AIAgent with a context_compressor, skipping __init__."""
     agent = AIAgent.__new__(AIAgent)
@@ -73,3 +108,151 @@ def test_switch_model_without_config_context_length():
         mock_ctx_len.assert_called_once()
         call_kwargs = mock_ctx_len.call_args.kwargs
         assert call_kwargs.get("config_context_length") is None
+
+
+def test_direct_start_model_override_does_not_inherit_profile_context_length():
+    """A CLI ``--model`` startup override must not inherit another model's window."""
+    cfg = {
+        "model": {
+            "default": "kimi-k3",
+            "provider": "custom:kimi-coding-1m",
+            "base_url": "https://api.kimi.com/coding",
+            "context_length": 1_048_576,
+        },
+        "custom_providers": [
+            {
+                "name": "kimi-coding-1m",
+                "base_url": "https://api.kimi.com/coding",
+                "models": {"kimi-k3": {"context_length": 1_048_576}},
+            }
+        ],
+    }
+    agent = _make_direct_start_agent(
+        cfg,
+        model="gpt-5.6-sol",
+        provider="openai-codex",
+        base_url="https://chatgpt.com/backend-api/codex",
+    )
+
+    assert agent.context_compressor.config_context_length is None
+    assert agent.context_compressor.context_length == 272_000
+
+
+def test_direct_start_preserves_context_for_normalized_default_model_alias():
+    """Equivalent vendor-prefixed defaults still own their explicit window."""
+    cfg = {
+        "model": {
+            "default": "openai/gpt-5.6-sol",
+            "provider": "openai-codex",
+            "base_url": "https://chatgpt.com/backend-api/codex",
+            "context_length": 272_000,
+        }
+    }
+
+    agent = _make_direct_start_agent(
+        cfg,
+        model="gpt-5.6-sol",
+        provider="openai-codex",
+        base_url="https://chatgpt.com/backend-api/codex",
+    )
+
+    assert agent.context_compressor.config_context_length == 272_000
+    assert agent.context_compressor.context_length == 272_000
+
+
+def test_direct_start_same_model_on_different_route_drops_context_override():
+    """Context pins are route-specific even when the model slug is unchanged."""
+    cfg = {
+        "model": {
+            "default": "gpt-5.6-sol",
+            "provider": "custom:large-sol-route",
+            "base_url": "https://large-sol.example/v1",
+            "context_length": 1_048_576,
+        }
+    }
+
+    agent = _make_direct_start_agent(
+        cfg,
+        model="gpt-5.6-sol",
+        provider="openai-codex",
+        base_url="https://chatgpt.com/backend-api/codex",
+    )
+
+    assert agent.context_compressor.config_context_length is None
+    assert agent.context_compressor.context_length == 272_000
+
+
+def test_direct_start_preserves_context_for_bare_aggregator_model():
+    """Aggregator normalization must compare both sides, not rewrite one side."""
+    cfg = {
+        "model": {
+            "default": "gpt-5.4",
+            "provider": "openrouter",
+            "context_length": 1_000_000,
+        }
+    }
+
+    agent = _make_direct_start_agent(
+        cfg,
+        model="gpt-5.4",
+        provider="openrouter",
+        base_url="https://openrouter.ai/api/v1",
+    )
+
+    assert agent.context_compressor.config_context_length == 1_000_000
+
+
+def test_direct_start_preserves_context_for_provider_alias():
+    """Canonical provider aliases identify the same route when no URL is pinned."""
+    cfg = {
+        "model": {
+            "default": "gemini-2.5-pro",
+            "provider": "google",
+            "context_length": 1_000_000,
+        }
+    }
+
+    agent = _make_direct_start_agent(
+        cfg,
+        model="gemini-2.5-pro",
+        provider="gemini",
+        base_url="https://generativelanguage.googleapis.com/v1beta/openai",
+    )
+
+    assert agent.context_compressor.config_context_length == 1_000_000
+
+
+def test_direct_start_named_custom_route_resolves_configured_base_url():
+    """Named custom providers must not collapse to one generic custom route."""
+    cfg = {
+        "model": {
+            "default": "shared-model",
+            "provider": "custom:large-route",
+            "context_length": 1_048_576,
+        },
+        "custom_providers": [
+            {
+                "name": "large-route",
+                "base_url": "https://large.example/v1",
+            }
+        ],
+    }
+
+    agent = _make_direct_start_agent(
+        cfg,
+        model="shared-model",
+        provider="custom",
+        base_url="https://small.example/v1",
+    )
+
+    assert agent.context_compressor.config_context_length is None
+    assert agent.context_compressor.context_length == 272_000
+
+    matching_agent = _make_direct_start_agent(
+        cfg,
+        model="shared-model",
+        provider="custom",
+        base_url="https://large.example/v1",
+    )
+
+    assert matching_agent.context_compressor.config_context_length == 1_048_576