diff --git a/run_agent.py b/run_agent.py
index cf418a5766fe..088b481ebe59 100644
--- a/run_agent.py
+++ b/run_agent.py
@@ -1920,6 +1920,8 @@ def _run_review():
                      contextlib.redirect_stderr(_devnull):
                     review_agent = AIAgent(
                         model=self.model,
+                        base_url=self._base_url,
+                        api_key=self.api_key,
                         max_iterations=8,
                         quiet_mode=True,
                         platform=self.platform,
diff --git a/tests/run_agent/test_review_agent_runtime.py b/tests/run_agent/test_review_agent_runtime.py
new file mode 100644
index 000000000000..81d0a79b63af
--- /dev/null
+++ b/tests/run_agent/test_review_agent_runtime.py
@@ -0,0 +1,76 @@
+"""Regression test: background review agent must inherit full runtime config.
+
+The background memory/skill review agent must receive base_url and api_key
+from the parent agent so it hits the same provider endpoint. Without these,
+custom provider users get model_not_supported errors from the review path
+even though the primary request succeeded.
+"""
+
+import threading
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+
+def _make_parent_agent():
+    """Build a minimal AIAgent-like object with the fields _run_review reads."""
+    from run_agent import AIAgent
+
+    # Use object.__new__ to skip the heavy __init__.
+    agent = object.__new__(AIAgent)
+    agent.model = "gpt-5.4"
+    agent._base_url = "http://192.168.66.12:4000/v1/"
+    agent.api_key = "sk-test-key-123"
+    agent.platform = "telegram"
+    agent.provider = "custom-provider"
+    agent._memory_store = MagicMock()
+    agent._memory_enabled = True
+    agent._user_profile_enabled = False
+    agent._memory_nudge_interval = 0
+    agent._skill_nudge_interval = 0
+    agent.background_review_callback = None
+    agent._safe_print = MagicMock()
+    agent._MEMORY_REVIEW_PROMPT = "review memory"
+    agent._SKILL_REVIEW_PROMPT = "review skills"
+    agent._COMBINED_REVIEW_PROMPT = "review both"
+    return agent
+
+
+def test_review_agent_inherits_base_url_and_api_key():
+    """The review agent must receive base_url and api_key from the parent."""
+    parent = _make_parent_agent()
+
+    captured = {}
+
+    def spy_init(self, **kwargs):
+        captured.update(kwargs)
+        # Don't actually run the full init — just record what was passed.
+        raise RuntimeError("spy: stop here")
+
+    with patch.object(parent.__class__, "__init__", spy_init):
+        started_target = None
+        original_thread_init = threading.Thread.__init__
+
+        def capture_thread_init(self_thread, *args, **kwargs):
+            nonlocal started_target
+            started_target = kwargs.get("target")
+            original_thread_init(self_thread, *args, **kwargs)
+
+        with patch.object(threading.Thread, "__init__", capture_thread_init), \
+             patch.object(threading.Thread, "start", lambda self: None):
+            parent._spawn_background_review(
+                messages_snapshot=[],
+                review_memory=True,
+                review_skills=False,
+            )
+
+        # Now call the captured target (the _run_review closure) directly
+        assert started_target is not None, "_run_review thread target not captured"
+        started_target()
+
+    assert captured.get("base_url") == "http://192.168.66.12:4000/v1/", \
+        f"base_url not passed to review agent: {captured}"
+    assert captured.get("api_key") == "sk-test-key-123", \
+        f"api_key not passed to review agent: {captured}"
+    assert captured.get("model") == "gpt-5.4"
+    assert captured.get("provider") == "custom-provider"