diff --git a/docker-compose.yml b/docker-compose.yml
index 94d33dc..6821f7b 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -12,7 +12,7 @@ services:
       DIST=$$(find /usr/local/lib -path '*/claude-max-api-proxy/dist' -type d | head -1) &&
       sed -i 's/startServer({ port })/startServer({ port, host: process.env.HOST || \"127.0.0.1\" })/' $$DIST/server/standalone.js &&
       sed -i 's/\"--no-session-persistence\",/\"--no-session-persistence\",\"--dangerously-skip-permissions\",/' $$DIST/subprocess/manager.js &&
-      sed -i 's/const DEFAULT_TIMEOUT = 300000;/const DEFAULT_TIMEOUT = 1200000;/' $$DIST/subprocess/manager.js &&
+      sed -i 's/const DEFAULT_TIMEOUT = 300000;/const DEFAULT_TIMEOUT = 86400000;/' $$DIST/subprocess/manager.js &&
       cp /proxy-patches/openai-to-cli.js $$DIST/adapter/openai-to-cli.js &&
       cp /proxy-patches/cli-to-openai.js $$DIST/adapter/cli-to-openai.js &&
       cp /proxy-patches/routes.js $$DIST/server/routes.js &&
diff --git a/proxy-patches/routes.js b/proxy-patches/routes.js
index da9ed7c..8eb8e58 100644
--- a/proxy-patches/routes.js
+++ b/proxy-patches/routes.js
@@ -35,6 +35,15 @@ const STREAM_HOOK_URL = process.env.ARIA_STREAM_HOOK_URL
 const TOOL_RESULT_MAX_CHARS = 4096;
 const TOOL_INPUT_MAX_CHARS = 2048;
 
+// Idle-Timeout: Subprocess wird gekillt wenn ueber IDLE_TIMEOUT_MS keine
+// Aktivitaet (message/content_delta) ankommt. Loest das alte Hard-Timeout-
+// Problem fuer lange Agent-Sessions (Pentests etc.) — ARIA darf ewig
+// arbeiten solange sie regelmaessig was emittiert, aber wenn der Subprocess
+// hartnaeckig haengt, schlaegt der Watchdog trotzdem zu.
+// Default 20min Idle. Override via env ARIA_IDLE_TIMEOUT_MS.
+// 0 = deaktiviert (nicht empfohlen).
+const IDLE_TIMEOUT_MS = parseInt(process.env.ARIA_IDLE_TIMEOUT_MS || "1200000", 10);
+
 /**
  * Generic Fire-and-forget POST an die Bridge. Keine Awaits, keine Fehler
  * nach oben. Eingesetzt fuer Tool-Hook + Stream-Hook.
@@ -91,6 +100,50 @@ function _trackSubprocess(requestId, subprocess) {
     subprocess.on("error", cleanup);
 }
 
+/**
+ * Idle-Watchdog: killt den Subprocess wenn ueber IDLE_TIMEOUT_MS hinweg
+ * keine message/content_delta Events ankommen. Wird beim Start gesetzt,
+ * bei jedem Event reset, bei close/error/result gestoppt.
+ *
+ * Stream-Event 'end' wird durch den normalen close-Listener im Handler
+ * gefeuert — wir muessen hier nichts extra emittieren.
+ */
+function _attachIdleWatchdog(subprocess, requestId) {
+    if (!IDLE_TIMEOUT_MS || IDLE_TIMEOUT_MS <= 0) return; // disabled
+    let timer = null;
+    let killed = false;
+
+    function _kill() {
+        if (killed) return;
+        killed = true;
+        const mins = Math.round(IDLE_TIMEOUT_MS / 60000);
+        console.warn(`[aria-idle] killing subprocess ${requestId} after ${mins}min idle`);
+        try { subprocess.kill(); } catch (_) {}
+        _emitStreamEvent(requestId, "end", { reason: "idle_timeout", idleMs: IDLE_TIMEOUT_MS });
+    }
+
+    function _reset() {
+        if (killed) return;
+        if (timer) clearTimeout(timer);
+        timer = setTimeout(_kill, IDLE_TIMEOUT_MS);
+    }
+
+    function _stop() {
+        if (timer) { clearTimeout(timer); timer = null; }
+    }
+
+    // Initial-Timer setzen
+    _reset();
+
+    // Jedes Event vom Subprozess zaehlt als Lebenszeichen
+    subprocess.on("message", _reset);
+    subprocess.on("content_delta", _reset);
+    // Result/close/error → endgueltig stop
+    subprocess.on("result", _stop);
+    subprocess.on("close", _stop);
+    subprocess.on("error", _stop);
+}
+
 /**
  * Hookt assistant + user Events und pusht beides an Bridge:
  *  - Alt-API: nur Tool-Namen an /internal/agent-activity (Gedanken-Stream)
@@ -177,8 +230,11 @@ export async function handleChatCompletions(req, res) {
         const subprocess = new ClaudeSubprocess();
         // ARIA-Patch: Tool-Use-Events + voller Live-Stream an die Bridge.
         // Plus: Subprocess fuer Not-Aus tracken (Hard-Kill via /v1/cancel-all).
+        // Plus: Idle-Watchdog — Subprocess darf ewig laufen solange Events
+        // kommen, wird aber gekillt nach IDLE_TIMEOUT_MS Inaktivitaet.
         _attachToolHook(subprocess, requestId);
         _trackSubprocess(requestId, subprocess);
+        _attachIdleWatchdog(subprocess, requestId);
         _emitStreamEvent(requestId, "start", { model: body.model || null });
         subprocess.on("result", () => _emitStreamEvent(requestId, "end", { reason: "result" }));
         subprocess.on("close", (code) => _emitStreamEvent(requestId, "end", { reason: "close", code }));