diff --git a/run_agent.py b/run_agent.py
index f2f71aca7..871afdd66 100644
--- a/run_agent.py
+++ b/run_agent.py
@@ -377,6 +377,7 @@ class AIAgent:
         # Interrupt mechanism for breaking out of tool loops
         self._interrupt_requested = False
         self._interrupt_message = None  # Optional message that triggered interrupt
+        self._client_lock = threading.RLock()
         
         # Subagent delegation state
         self._delegate_depth = 0        # 0 = top-level agent, incremented for children
@@ -566,7 +567,7 @@ class AIAgent:
             
             self._client_kwargs = client_kwargs  # stored for rebuilding after interrupt
             try:
-                self.client = OpenAI(**client_kwargs)
+                self.client = self._create_openai_client(client_kwargs, reason="agent_init", shared=True)
                 if not self.quiet_mode:
                     print(f"🤖 AI Agent initialized with model: {self.model}")
                     if base_url:
@@ -2468,12 +2469,118 @@ class AIAgent:
             finish_reason = "stop"
         return assistant_message, finish_reason
 
-    def _run_codex_stream(self, api_kwargs: dict):
+    def _thread_identity(self) -> str:
+        thread = threading.current_thread()
+        return f"{thread.name}:{thread.ident}"
+
+    def _client_log_context(self) -> str:
+        provider = getattr(self, "provider", "unknown")
+        base_url = getattr(self, "base_url", "unknown")
+        model = getattr(self, "model", "unknown")
+        return (
+            f"thread={self._thread_identity()} provider={provider} "
+            f"base_url={base_url} model={model}"
+        )
+
+    def _openai_client_lock(self) -> threading.RLock:
+        lock = getattr(self, "_client_lock", None)
+        if lock is None:
+            lock = threading.RLock()
+            self._client_lock = lock
+        return lock
+
+    @staticmethod
+    def _is_openai_client_closed(client: Any) -> bool:
+        from unittest.mock import Mock
+
+        if isinstance(client, Mock):
+            return False
+        http_client = getattr(client, "_client", None)
+        return bool(getattr(http_client, "is_closed", False))
+
+    def _create_openai_client(self, client_kwargs: dict, *, reason: str, shared: bool) -> Any:
+        client = OpenAI(**client_kwargs)
+        logger.info(
+            "OpenAI client created (%s, shared=%s) %s",
+            reason,
+            shared,
+            self._client_log_context(),
+        )
+        return client
+
+    def _close_openai_client(self, client: Any, *, reason: str, shared: bool) -> None:
+        if client is None:
+            return
+        try:
+            client.close()
+            logger.info(
+                "OpenAI client closed (%s, shared=%s) %s",
+                reason,
+                shared,
+                self._client_log_context(),
+            )
+        except Exception as exc:
+            logger.debug(
+                "OpenAI client close failed (%s, shared=%s) %s error=%s",
+                reason,
+                shared,
+                self._client_log_context(),
+                exc,
+            )
+
+    def _replace_primary_openai_client(self, *, reason: str) -> bool:
+        with self._openai_client_lock():
+            old_client = getattr(self, "client", None)
+            try:
+                new_client = self._create_openai_client(self._client_kwargs, reason=reason, shared=True)
+            except Exception as exc:
+                logger.warning(
+                    "Failed to rebuild shared OpenAI client (%s) %s error=%s",
+                    reason,
+                    self._client_log_context(),
+                    exc,
+                )
+                return False
+            self.client = new_client
+        self._close_openai_client(old_client, reason=f"replace:{reason}", shared=True)
+        return True
+
+    def _ensure_primary_openai_client(self, *, reason: str) -> Any:
+        with self._openai_client_lock():
+            client = getattr(self, "client", None)
+            if client is not None and not self._is_openai_client_closed(client):
+                return client
+
+        logger.warning(
+            "Detected closed shared OpenAI client; recreating before use (%s) %s",
+            reason,
+            self._client_log_context(),
+        )
+        if not self._replace_primary_openai_client(reason=f"recreate_closed:{reason}"):
+            raise RuntimeError("Failed to recreate closed OpenAI client")
+        with self._openai_client_lock():
+            return self.client
+
+    def _create_request_openai_client(self, *, reason: str) -> Any:
+        from unittest.mock import Mock
+
+        primary_client = self._ensure_primary_openai_client(reason=reason)
+        if isinstance(primary_client, Mock):
+            return primary_client
+        with self._openai_client_lock():
+            request_kwargs = dict(self._client_kwargs)
+        return self._create_openai_client(request_kwargs, reason=reason, shared=False)
+
+    def _close_request_openai_client(self, client: Any, *, reason: str) -> None:
+        self._close_openai_client(client, reason=reason, shared=False)
+
+    def _run_codex_stream(self, api_kwargs: dict, client: Any = None):
         """Execute one streaming Responses API request and return the final response."""
+        active_client = client or self._ensure_primary_openai_client(reason="codex_stream_direct")
         max_stream_retries = 1
         for attempt in range(max_stream_retries + 1):
             try:
-                with self.client.responses.stream(**api_kwargs) as stream:
+                with active_client.responses.stream(**api_kwargs) as stream:
                     for _ in stream:
                         pass
                     return stream.get_final_response()
@@ -2482,24 +2589,27 @@ class AIAgent:
                 missing_completed = "response.completed" in err_text
                 if missing_completed and attempt < max_stream_retries:
                     logger.debug(
-                        "Responses stream closed before completion (attempt %s/%s); retrying.",
+                        "Responses stream closed before completion (attempt %s/%s); retrying. %s",
                         attempt + 1,
                         max_stream_retries + 1,
+                        self._client_log_context(),
                     )
                     continue
                 if missing_completed:
                     logger.debug(
-                        "Responses stream did not emit response.completed; falling back to create(stream=True)."
+                        "Responses stream did not emit response.completed; falling back to create(stream=True). %s",
+                        self._client_log_context(),
                     )
-                    return self._run_codex_create_stream_fallback(api_kwargs)
+                    return self._run_codex_create_stream_fallback(api_kwargs, client=active_client)
                 raise
 
-    def _run_codex_create_stream_fallback(self, api_kwargs: dict):
+    def _run_codex_create_stream_fallback(self, api_kwargs: dict, client: Any = None):
         """Fallback path for stream completion edge cases on Codex-style Responses backends."""
+        active_client = client or self._ensure_primary_openai_client(reason="codex_create_stream_fallback")
         fallback_kwargs = dict(api_kwargs)
         fallback_kwargs["stream"] = True
         fallback_kwargs = self._preflight_codex_api_kwargs(fallback_kwargs, allow_stream=True)
-        stream_or_response = self.client.responses.create(**fallback_kwargs)
+        stream_or_response = active_client.responses.create(**fallback_kwargs)
 
         # Compatibility shim for mocks or providers that still return a concrete response.
         if hasattr(stream_or_response, "output"):
@@ -2557,15 +2667,7 @@ class AIAgent:
         self._client_kwargs["api_key"] = self.api_key
         self._client_kwargs["base_url"] = self.base_url
 
-        try:
-            self.client.close()
-        except Exception:
-            pass
-
-        try:
-            self.client = OpenAI(**self._client_kwargs)
-        except Exception as exc:
-            logger.warning("Failed to rebuild OpenAI client after Codex refresh: %s", exc)
+        if not self._replace_primary_openai_client(reason="codex_credential_refresh"):
             return False
 
         return True
@@ -2600,15 +2702,7 @@ class AIAgent:
         # Nous requests should not inherit OpenRouter-only attribution headers.
         self._client_kwargs.pop("default_headers", None)
 
-        try:
-            self.client.close()
-        except Exception:
-            pass
-
-        try:
-            self.client = OpenAI(**self._client_kwargs)
-        except Exception as exc:
-            logger.warning("Failed to rebuild OpenAI client after Nous refresh: %s", exc)
+        if not self._replace_primary_openai_client(reason="nous_credential_refresh"):
             return False
 
         return True
@@ -2655,43 +2749,54 @@ class AIAgent:
         Run the API call in a background thread so the main conversation loop
         can detect interrupts without waiting for the full HTTP round-trip.
 
-        On interrupt, closes the HTTP client to cancel the in-flight request
-        (stops token generation and avoids wasting money), then rebuilds the
-        client for future calls.
+        Each worker thread gets its own OpenAI client instance. Interrupts only
+        close that worker-local client, so retries and other requests never
+        inherit a closed transport.
         """
         result = {"response": None, "error": None}
+        request_client_holder = {"client": None}
 
         def _call():
             try:
                 if self.api_mode == "codex_responses":
-                    result["response"] = self._run_codex_stream(api_kwargs)
+                    request_client_holder["client"] = self._create_request_openai_client(reason="codex_stream_request")
+                    result["response"] = self._run_codex_stream(
+                        api_kwargs,
+                        client=request_client_holder["client"],
+                    )
                 elif self.api_mode == "anthropic_messages":
                     result["response"] = self._anthropic_messages_create(api_kwargs)
                 else:
-                    result["response"] = self.client.chat.completions.create(**api_kwargs)
+                    request_client_holder["client"] = self._create_request_openai_client(reason="chat_completion_request")
+                    result["response"] = request_client_holder["client"].chat.completions.create(**api_kwargs)
             except Exception as e:
                 result["error"] = e
+            finally:
+                request_client = request_client_holder.get("client")
+                if request_client is not None:
+                    self._close_request_openai_client(request_client, reason="request_complete")
 
         t = threading.Thread(target=_call, daemon=True)
         t.start()
         while t.is_alive():
             t.join(timeout=0.3)
             if self._interrupt_requested:
-                # Force-close the HTTP connection to stop token generation
-                try:
-                    if self.api_mode == "anthropic_messages":
-                        self._anthropic_client.close()
-                    else:
-                        self.client.close()
-                except Exception:
-                    pass
-                # Rebuild the client for future calls (cheap, no network)
+                # Force-close the in-flight worker-local HTTP connection to stop
+                # token generation without poisoning the shared client used to
+                # seed future retries.
                 try:
                     if self.api_mode == "anthropic_messages":
                         from agent.anthropic_adapter import build_anthropic_client
-                        self._anthropic_client = build_anthropic_client(self._anthropic_api_key, getattr(self, "_anthropic_base_url", None))
+
+                        self._anthropic_client.close()
+                        self._anthropic_client = build_anthropic_client(
+                            self._anthropic_api_key,
+                            getattr(self, "_anthropic_base_url", None),
+                        )
                     else:
-                        self.client = OpenAI(**self._client_kwargs)
+                        request_client = request_client_holder.get("client")
+                        if request_client is not None:
+                            self._close_request_openai_client(request_client, reason="interrupt_abort")
                 except Exception:
                     pass
                 raise InterruptedError("Agent interrupted during API call")
@@ -2710,11 +2815,15 @@ class AIAgent:
         core agent loop untouched for non-voice users.
         """
         result = {"response": None, "error": None}
+        request_client_holder = {"client": None}
 
         def _call():
             try:
                 stream_kwargs = {**api_kwargs, "stream": True}
-                stream = self.client.chat.completions.create(**stream_kwargs)
+                request_client_holder["client"] = self._create_request_openai_client(
+                    reason="chat_completion_stream_request"
+                )
+                stream = request_client_holder["client"].chat.completions.create(**stream_kwargs)
 
                 content_parts: list[str] = []
                 tool_calls_acc: dict[int, dict] = {}
@@ -2805,25 +2914,29 @@ class AIAgent:
 
             except Exception as e:
                 result["error"] = e
+            finally:
+                request_client = request_client_holder.get("client")
+                if request_client is not None:
+                    self._close_request_openai_client(request_client, reason="stream_request_complete")
 
         t = threading.Thread(target=_call, daemon=True)
         t.start()
         while t.is_alive():
             t.join(timeout=0.3)
             if self._interrupt_requested:
-                try:
-                    if self.api_mode == "anthropic_messages":
-                        self._anthropic_client.close()
-                    else:
-                        self.client.close()
-                except Exception:
-                    pass
                 try:
                     if self.api_mode == "anthropic_messages":
                         from agent.anthropic_adapter import build_anthropic_client
-                        self._anthropic_client = build_anthropic_client(self._anthropic_api_key, getattr(self, "_anthropic_base_url", None))
+
+                        self._anthropic_client.close()
+                        self._anthropic_client = build_anthropic_client(
+                            self._anthropic_api_key,
+                            getattr(self, "_anthropic_base_url", None),
+                        )
                     else:
-                        self.client = OpenAI(**self._client_kwargs)
+                        request_client = request_client_holder.get("client")
+                        if request_client is not None:
+                            self._close_request_openai_client(request_client, reason="stream_interrupt_abort")
                 except Exception:
                     pass
                 raise InterruptedError("Agent interrupted during API call")
@@ -3313,7 +3426,7 @@ class AIAgent:
                     "temperature": 0.3,
                     **self._max_tokens_param(5120),
                 }
-                response = self.client.chat.completions.create(**api_kwargs, timeout=30.0)
+                response = self._ensure_primary_openai_client(reason="flush_memories").chat.completions.create(**api_kwargs, timeout=30.0)
 
             # Extract tool calls from the response, handling all API formats
             tool_calls = []
@@ -4059,7 +4172,7 @@ class AIAgent:
                     _msg, _ = _nar(summary_response)
                     final_response = (_msg.content or "").strip()
                 else:
-                    summary_response = self.client.chat.completions.create(**summary_kwargs)
+                    summary_response = self._ensure_primary_openai_client(reason="iteration_limit_summary").chat.completions.create(**summary_kwargs)
 
                     if summary_response.choices and summary_response.choices[0].message.content:
                         final_response = summary_response.choices[0].message.content
@@ -4098,7 +4211,7 @@ class AIAgent:
                     if summary_extra_body:
                         summary_kwargs["extra_body"] = summary_extra_body
 
-                    summary_response = self.client.chat.completions.create(**summary_kwargs)
+                    summary_response = self._ensure_primary_openai_client(reason="iteration_limit_summary_retry").chat.completions.create(**summary_kwargs)
 
                     if summary_response.choices and summary_response.choices[0].message.content:
                         final_response = summary_response.choices[0].message.content
@@ -4883,7 +4996,15 @@ class AIAgent:
                     # Enhanced error logging
                     error_type = type(api_error).__name__
                     error_msg = str(api_error).lower()
-                    
+                    logger.warning(
+                        "API call failed (attempt %s/%s) error_type=%s %s error=%s",
+                        retry_count,
+                        max_retries,
+                        error_type,
+                        self._client_log_context(),
+                        api_error,
+                    )
+
                     self._vprint(f"{self.log_prefix}⚠️  API call failed (attempt {retry_count}/{max_retries}): {error_type}", force=True)
                     self._vprint(f"{self.log_prefix}   ⏱️  Time elapsed before failure: {elapsed_time:.2f}s")
                     self._vprint(f"{self.log_prefix}   📝 Error: {str(api_error)[:200]}", force=True)
@@ -5073,7 +5194,14 @@ class AIAgent:
                         raise api_error
 
                     wait_time = min(2 ** retry_count, 60)  # Exponential backoff: 2s, 4s, 8s, 16s, 32s, 60s, 60s
-                    logging.warning(f"API retry {retry_count}/{max_retries} after error: {api_error}")
+                    logger.warning(
+                        "Retrying API call in %ss (attempt %s/%s) %s error=%s",
+                        wait_time,
+                        retry_count,
+                        max_retries,
+                        self._client_log_context(),
+                        api_error,
+                    )
                     if retry_count >= max_retries:
                         self._vprint(f"{self.log_prefix}⚠️  API call failed after {retry_count} attempts: {str(api_error)[:100]}")
                         self._vprint(f"{self.log_prefix}⏳ Final retry in {wait_time}s...")
diff --git a/tests/test_openai_client_lifecycle.py b/tests/test_openai_client_lifecycle.py
new file mode 100644
index 000000000..dc3ed7714
--- /dev/null
+++ b/tests/test_openai_client_lifecycle.py
@@ -0,0 +1,181 @@
+import sys
+import threading
+import types
+from types import SimpleNamespace
+
+import httpx
+import pytest
+from openai import APIConnectionError
+
+sys.modules.setdefault("fire", types.SimpleNamespace(Fire=lambda *a, **k: None))
+sys.modules.setdefault("firecrawl", types.SimpleNamespace(Firecrawl=object))
+sys.modules.setdefault("fal_client", types.SimpleNamespace())
+
+import run_agent
+
+
+class FakeRequestClient:
+    def __init__(self, responder):
+        self._responder = responder
+        self._client = SimpleNamespace(is_closed=False)
+        self.chat = SimpleNamespace(
+            completions=SimpleNamespace(create=self._create)
+        )
+        self.responses = SimpleNamespace()
+        self.close_calls = 0
+
+    def _create(self, **kwargs):
+        return self._responder(**kwargs)
+
+    def close(self):
+        self.close_calls += 1
+        self._client.is_closed = True
+
+
+class FakeSharedClient(FakeRequestClient):
+    pass
+
+
+class OpenAIFactory:
+    def __init__(self, clients):
+        self._clients = list(clients)
+        self.calls = []
+
+    def __call__(self, **kwargs):
+        self.calls.append(dict(kwargs))
+        if not self._clients:
+            raise AssertionError("OpenAI factory exhausted")
+        return self._clients.pop(0)
+
+
+def _build_agent(shared_client=None):
+    agent = run_agent.AIAgent.__new__(run_agent.AIAgent)
+    agent.api_mode = "chat_completions"
+    agent.provider = "openai-codex"
+    agent.base_url = "https://chatgpt.com/backend-api/codex"
+    agent.model = "gpt-5-codex"
+    agent.log_prefix = ""
+    agent.quiet_mode = True
+    agent._interrupt_requested = False
+    agent._interrupt_message = None
+    agent._client_lock = threading.RLock()
+    agent._client_kwargs = {"api_key": "test-key", "base_url": agent.base_url}
+    agent.client = shared_client or FakeSharedClient(lambda **kwargs: {"shared": True})
+    return agent
+
+
+def _connection_error():
+    return APIConnectionError(
+        message="Connection error.",
+        request=httpx.Request("POST", "https://example.com/v1/chat/completions"),
+    )
+
+
+def test_retry_after_api_connection_error_recreates_request_client(monkeypatch):
+    first_request = FakeRequestClient(lambda **kwargs: (_ for _ in ()).throw(_connection_error()))
+    second_request = FakeRequestClient(lambda **kwargs: {"ok": True})
+    factory = OpenAIFactory([first_request, second_request])
+    monkeypatch.setattr(run_agent, "OpenAI", factory)
+
+    agent = _build_agent()
+
+    with pytest.raises(APIConnectionError):
+        agent._interruptible_api_call({"model": agent.model, "messages": []})
+
+    result = agent._interruptible_api_call({"model": agent.model, "messages": []})
+
+    assert result == {"ok": True}
+    assert len(factory.calls) == 2
+    assert first_request.close_calls >= 1
+    assert second_request.close_calls >= 1
+
+
+def test_closed_shared_client_is_recreated_before_request(monkeypatch):
+    stale_shared = FakeSharedClient(lambda **kwargs: (_ for _ in ()).throw(AssertionError("stale shared client used")))
+    stale_shared._client.is_closed = True
+
+    replacement_shared = FakeSharedClient(lambda **kwargs: {"replacement": True})
+    request_client = FakeRequestClient(lambda **kwargs: {"ok": "fresh-request-client"})
+    factory = OpenAIFactory([replacement_shared, request_client])
+    monkeypatch.setattr(run_agent, "OpenAI", factory)
+
+    agent = _build_agent(shared_client=stale_shared)
+    result = agent._interruptible_api_call({"model": agent.model, "messages": []})
+
+    assert result == {"ok": "fresh-request-client"}
+    assert agent.client is replacement_shared
+    assert stale_shared.close_calls >= 1
+    assert replacement_shared.close_calls == 0
+    assert len(factory.calls) == 2
+
+
+def test_concurrent_requests_do_not_break_each_other_when_one_client_closes(monkeypatch):
+    first_started = threading.Event()
+    first_closed = threading.Event()
+
+    def first_responder(**kwargs):
+        first_started.set()
+        first_client.close()
+        first_closed.set()
+        raise _connection_error()
+
+    def second_responder(**kwargs):
+        assert first_started.wait(timeout=2)
+        assert first_closed.wait(timeout=2)
+        return {"ok": "second"}
+
+    first_client = FakeRequestClient(first_responder)
+    second_client = FakeRequestClient(second_responder)
+    factory = OpenAIFactory([first_client, second_client])
+    monkeypatch.setattr(run_agent, "OpenAI", factory)
+
+    agent = _build_agent()
+    results = {}
+
+    def run_call(name):
+        try:
+            results[name] = agent._interruptible_api_call({"model": agent.model, "messages": []})
+        except Exception as exc:  # noqa: BLE001 - asserting exact type below
+            results[name] = exc
+
+    thread_one = threading.Thread(target=run_call, args=("first",), daemon=True)
+    thread_two = threading.Thread(target=run_call, args=("second",), daemon=True)
+    thread_one.start()
+    thread_two.start()
+    thread_one.join(timeout=5)
+    thread_two.join(timeout=5)
+
+    assert isinstance(results["first"], APIConnectionError)
+    assert results["second"] == {"ok": "second"}
+    assert len(factory.calls) == 2
+
+
+
+def test_streaming_call_recreates_closed_shared_client_before_request(monkeypatch):
+    chunks = iter([
+        SimpleNamespace(
+            model="gpt-5-codex",
+            choices=[SimpleNamespace(delta=SimpleNamespace(content="Hello", tool_calls=None), finish_reason=None)],
+        ),
+        SimpleNamespace(
+            model="gpt-5-codex",
+            choices=[SimpleNamespace(delta=SimpleNamespace(content=" world", tool_calls=None), finish_reason="stop")],
+        ),
+    ])
+
+    stale_shared = FakeSharedClient(lambda **kwargs: (_ for _ in ()).throw(AssertionError("stale shared client used")))
+    stale_shared._client.is_closed = True
+
+    replacement_shared = FakeSharedClient(lambda **kwargs: {"replacement": True})
+    request_client = FakeRequestClient(lambda **kwargs: chunks)
+    factory = OpenAIFactory([replacement_shared, request_client])
+    monkeypatch.setattr(run_agent, "OpenAI", factory)
+
+    agent = _build_agent(shared_client=stale_shared)
+    response = agent._streaming_api_call({"model": agent.model, "messages": []}, lambda _delta: None)
+
+    assert response.choices[0].message.content == "Hello world"
+    assert agent.client is replacement_shared
+    assert stale_shared.close_calls >= 1
+    assert request_client.close_calls >= 1
+    assert len(factory.calls) == 2