From 12b109b6640a573abf685d3c881cab2a9fc5c3aa Mon Sep 17 00:00:00 2001
From: Teknium <127238744+teknium1@users.noreply.github.com>
Date: Thu, 16 Apr 2026 02:32:21 -0700
Subject: [PATCH] fix: enable TCP keepalives to detect dead provider
 connections (#10324) (#10933)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When a custom provider drops a connection mid-stream, the TCP socket
can enter CLOSE-WAIT and the httpx read timeout may never fire —
epoll_wait blocks indefinitely because no data or error signal arrives.
The agent hangs until manually killed.

The existing defenses (httpx read timeout, stale stream detector,
_force_close_tcp_sockets) are all time-based and work correctly once
triggered, but they rely on the socket layer reporting the dead
connection. Without TCP keepalives, the kernel has no reason to probe
a silent connection.

Fix: inject SO_KEEPALIVE + TCP_KEEPIDLE/KEEPINTVL/KEEPCNT into the
httpx transport via socket_options. The kernel probes idle connections
after 30s, retries every 10s, gives up after 3 failures — dead peer
detected within ~60s instead of hanging forever.

Platform-aware: uses TCP_KEEPIDLE on Linux, TCP_KEEPALIVE on macOS.
Falls back silently if socket options aren't available (Windows, etc.).

Closes #10324
---
 run_agent.py | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/run_agent.py b/run_agent.py
index cb5dbf4b1..944217e6b 100644
--- a/run_agent.py
+++ b/run_agent.py
@@ -4366,6 +4366,29 @@ class AIAgent:
                 self._client_log_context(),
             )
             return client
+        # Inject TCP keepalives to detect dead connections faster (#10324).
+        # Without keepalives, a provider that drops mid-stream leaves the
+        # socket in CLOSE-WAIT and epoll_wait may never fire, causing the
+        # agent to hang indefinitely.  Keepalive probes detect the dead
+        # peer within ~60s (30s idle + 3×10s probes).
+        if "http_client" not in client_kwargs:
+            try:
+                import httpx as _httpx
+                import socket as _socket
+                _sock_opts = [(_socket.SOL_SOCKET, _socket.SO_KEEPALIVE, 1)]
+                if hasattr(_socket, "TCP_KEEPIDLE"):
+                    # Linux
+                    _sock_opts.append((_socket.IPPROTO_TCP, _socket.TCP_KEEPIDLE, 30))
+                    _sock_opts.append((_socket.IPPROTO_TCP, _socket.TCP_KEEPINTVL, 10))
+                    _sock_opts.append((_socket.IPPROTO_TCP, _socket.TCP_KEEPCNT, 3))
+                elif hasattr(_socket, "TCP_KEEPALIVE"):
+                    # macOS (uses TCP_KEEPALIVE instead of TCP_KEEPIDLE)
+                    _sock_opts.append((_socket.IPPROTO_TCP, _socket.TCP_KEEPALIVE, 30))
+                client_kwargs["http_client"] = _httpx.Client(
+                    transport=_httpx.HTTPTransport(socket_options=_sock_opts),
+                )
+            except Exception:
+                pass  # Fall through to default transport if socket opts fail
         client = OpenAI(**client_kwargs)
         logger.info(
             "OpenAI client created (%s, shared=%s) %s",