diff --git a/backend/apps/agents/manager/configure_provider_env.py b/backend/apps/agents/manager/configure_provider_env.py
index 327a2033..a7fa44f5 100644
--- a/backend/apps/agents/manager/configure_provider_env.py
+++ b/backend/apps/agents/manager/configure_provider_env.py
@@ -1,10 +1,9 @@
 """Configure the SDK environment for the run's provider route: set ANTHROPIC/OPENAI/GOOGLE
 auth env vars (direct key, OpenSwarm Pro proxy, OpenRouter, or 9Router) and pin subagent models,
-ensuring 9Router is up where the route needs it. sub_conns is the active-connection list for
-subagent-model fallback (empty today)."""
+ensuring 9Router is up where the route needs it."""
 
 import os
-from typing import Dict, List, Optional
+from typing import Dict, Optional
 
 from typeguard import typechecked
 
@@ -50,7 +49,6 @@ async def configure_provider_env(
     resolved_model: object,
     api_type: Optional[str],
     global_settings: AppSettings,
-    sub_conns: List,
 ) -> None:
     from backend.apps.nine_router import is_running as nine_router_running
     from backend.apps.agents.providers.registry import NINEROUTER_MODEL_PREFIXES as NINEROUTER_MODEL_PREFIXES
@@ -198,7 +196,9 @@ async def configure_provider_env(
                 "ANTHROPIC_API_KEY": "9router",
                 "ANTHROPIC_BASE_URL": "http://localhost:20128",
             }
-        # Pin subagents to whichever lane the user has, else CLI's default Haiku 4.5 hits 9Router with no Claude route and 401s. NOTE: callers pass sub_conns=[] today so this is inert (latent regression from the run/ split; pyright caught the dangling _conns ref).
+        # Pin subagents to whichever lane the user has, else the CLI's default Haiku 4.5 hits 9Router with no Claude route and every sub-agent 401s while the parent turn works. Fetched live here (fail-open []) so no caller can starve the pin with a stale list again, the run/ split did exactly that and silently killed sub-agents on router routes.
+        from backend.apps.nine_router import get_providers as p_get_providers
+        sub_conns = await p_get_providers()
         active = {c.get("provider") for c in sub_conns
                    if isinstance(c, dict) and c.get("isActive")}
         sub_model = None
diff --git a/backend/apps/agents/manager/run/RunOptions.py b/backend/apps/agents/manager/run/RunOptions.py
index 37b7f3da..e0ab25ec 100644
--- a/backend/apps/agents/manager/run/RunOptions.py
+++ b/backend/apps/agents/manager/run/RunOptions.py
@@ -188,7 +188,7 @@ class RunOptions(AgentManagerProtocol):
         }
         # cc/cx/gc/ag/gemini/openrouter prefixes force 9Router; route="api" bypasses to the provider's host directly; otherwise Pro proxy or key.
         await configure_provider_env(
-            options_kwargs, session, resolved_model, api_type, global_settings, []
+            options_kwargs, session, resolved_model, api_type, global_settings
         )
         if mcp_servers:
             options_kwargs["mcp_servers"] = mcp_servers
diff --git a/backend/tests/test_subagent_model_pin.py b/backend/tests/test_subagent_model_pin.py
new file mode 100644
index 00000000..d4a7318e
--- /dev/null
+++ b/backend/tests/test_subagent_model_pin.py
@@ -0,0 +1,45 @@
+"""The sub-agent model pin on the 9Router-direct route must come from LIVE router
+connections. The run/ split passed a hardcoded empty list, the pin never fired, and every
+sub-agent 401'd ("No credentials for provider: anthropic") while the parent turn worked."""
+import asyncio
+from typing import Dict
+
+from pytest import MonkeyPatch
+
+import backend.apps.agents.manager.configure_provider_env as cpe
+from backend.apps.agents.core.models import AgentSession
+from backend.apps.settings.models import AppSettings
+
+
+def run_env_for(connections: list, monkeypatch: MonkeyPatch) -> Dict:
+    import backend.apps.nine_router as nr_pkg
+
+    async def fake_get_providers() -> list:
+        return connections
+
+    monkeypatch.setattr(nr_pkg, "is_running", lambda: True)
+    monkeypatch.setattr(nr_pkg, "get_providers", fake_get_providers)
+    session = AgentSession(name="t", model="opus-4-8-cc")
+    options_kwargs: Dict = {}
+    asyncio.run(
+        cpe.configure_provider_env(
+            options_kwargs, session, "cc/claude-opus-4-8", "anthropic", AppSettings()
+        )
+    )
+    return options_kwargs.get("env", {})
+
+
+def test_subagent_pin_set_from_live_claude_connection(monkeypatch: MonkeyPatch) -> None:
+    env = run_env_for([{"provider": "claude", "isActive": True}], monkeypatch)
+    assert env.get("CLAUDE_CODE_SUBAGENT_MODEL") == "cc/claude-sonnet-4-6"
+    assert env.get("ANTHROPIC_SMALL_FAST_MODEL") == "cc/claude-haiku-4-5-20251001"
+
+
+def test_subagent_pin_absent_only_when_no_active_lane(monkeypatch: MonkeyPatch) -> None:
+    env = run_env_for([], monkeypatch)
+    assert "CLAUDE_CODE_SUBAGENT_MODEL" not in env
+
+
+def test_subagent_pin_codex_lane(monkeypatch: MonkeyPatch) -> None:
+    env = run_env_for([{"provider": "codex", "isActive": True}], monkeypatch)
+    assert env.get("CLAUDE_CODE_SUBAGENT_MODEL") == "cx/gpt-5.4-mini"