diff --git a/website/guide/configuration.md b/website/guide/configuration.md
index 5ed3bba..0925b49 100644
--- a/website/guide/configuration.md
+++ b/website/guide/configuration.md
@@ -172,3 +172,4 @@ python -m mempalace.mcp_server --palace /custom/palace
 | `MEMPAL_DIR` | Directory for auto-mining in hooks |
 | `MEMPALACE_MAX_BACKUPS` | Override `max_backups` retention count (`0` disables pruning) |
 | `MEMPALACE_BACKEND` | Select the storage backend (default `chroma`) — see [Storage backends](#storage-backends) for each backend's connection variables |
+| `MEMPALACE_MCP_IDLE_HOURS` | Hours with no MCP request before the server exits by itself (default `8`; `0` disables). See [Remote server](/guide/remote-server#operating-notes) |
diff --git a/website/guide/remote-server.md b/website/guide/remote-server.md
index 150f9cc..f4fb64e 100644
--- a/website/guide/remote-server.md
+++ b/website/guide/remote-server.md
@@ -202,7 +202,15 @@ messages between machines.
   server state, `GET /statusz` returns JSON with version, uptime, request
   counters, SQLite integrity, writer mode, and recent observed MCP clients.
   `/statusz` follows the bearer-token policy because it exposes operational
-  metadata; it is not a public liveness probe.
+  metadata; it is not a public liveness probe. Probe traffic does **not**
+  count as activity for the idle watchdog below; only MCP requests do.
+- **Idle shutdown**: the server exits by itself once `MEMPALACE_MCP_IDLE_HOURS`
+  have passed with no MCP request (default `8`). That default is there to reap
+  the per-session stdio servers that would otherwise pile up holding ChromaDB
+  and HNSW file handles, which is not the case a dedicated always-on server is
+  in. Set `MEMPALACE_MCP_IDLE_HOURS=0` to disable it, and make sure your
+  supervisor restarts on a *clean* exit (`Restart=always` rather than
+  `Restart=on-failure`), because the watchdog exits `0`.
 - **Fronting proxies (Tailscale, nginx)**: the recommended personal-fleet
   setup is a loopback bind behind a tailnet-only proxy — nothing touches the
   physical LAN and the tailnet provides encryption plus device identity: