diff --git a/pallas/_fastagent_patch.py b/pallas/_fastagent_patch.py
index 2e67732..bb8507b 100644
--- a/pallas/_fastagent_patch.py
+++ b/pallas/_fastagent_patch.py
@@ -46,9 +46,11 @@ from typing import Any
 import httpx
 
 from fast_agent.mcp import mcp_connection_manager as _mcm
+from fast_agent.mcp import mcp_agent_client_session as _macs
 from fast_agent.mcp.auth.context import request_bearer_token
 
 logger = logging.getLogger("pallas.forward")
+_trace_logger = logging.getLogger("pallas.forward.trace")
 
 
 class _DynamicBearerAuth(httpx.Auth):
@@ -329,12 +331,54 @@ def _refresh_forward_servers() -> None:
     logger.debug("forward.no_config_found searched=%s", _candidate_config_paths())
 
 
+# ── send_request traceback capture ───────────────────────────────────────────
+# fast-agent's ``MCPAgentClientSession.send_request`` catches every
+# downstream-transport exception, logs ``"send_request failed: <str(e)>"``
+# *without* ``exc_info=True``, and re-raises — which means the exception
+# propagates up to the agent loop where it is serialised as a tool result
+# string (``"object NoneType can't be used in 'await' expression"`` is the
+# canonical symptom) with no traceback anywhere.
+#
+# We wrap ``send_request`` so Pallas can emit ``logger.exception(...)`` with
+# the full stack before re-raising.  The original logger still fires its
+# one-line summary; our wrapper adds the frames next to it in pallas.log.
+# No behavioural change — we re-raise the same exception.
+_original_send_request = _macs.MCPAgentClientSession.send_request
+
+
+async def _send_request_with_trace(self, *args, **kwargs):
+    try:
+        return await _original_send_request(self, *args, **kwargs)
+    except BaseException as exc:  # ExceptionGroup flows through BaseException
+        server = getattr(self, "session_server_name", None) or "unknown"
+        request_method = "?"
+        if args:
+            root = getattr(args[0], "root", None)
+            request_method = getattr(root, "method", "?") or "?"
+        _trace_logger.exception(
+            "send_request failed server=%s method=%s exc_type=%s",
+            server,
+            request_method,
+            type(exc).__name__,
+        )
+        raise
+
+
+def _patch_send_request() -> None:
+    if getattr(_macs.MCPAgentClientSession.send_request, "_pallas_trace_patched", False):
+        return
+    _send_request_with_trace._pallas_trace_patched = True  # type: ignore[attr-defined]
+    _macs.MCPAgentClientSession.send_request = _send_request_with_trace  # type: ignore[assignment]
+    logger.info("send_request traceback-capture patch installed")
+
+
 def install() -> None:
     if getattr(_mcm._prepare_headers_and_auth, "_pallas_forward_patched", False):
         return
     _refresh_forward_servers()
     _prepare_headers_and_auth_with_forward._pallas_forward_patched = True  # type: ignore[attr-defined]
     _mcm._prepare_headers_and_auth = _prepare_headers_and_auth_with_forward
+    _patch_send_request()
     # INFO so it always appears in the journal at boot — greppable proof
     # that the patch ran before any agent started.
     logger.info(