diff --git a/config/config.go b/config/config.go
index 1cfadd0..e5005f8 100644
--- a/config/config.go
+++ b/config/config.go
@@ -1,6 +1,7 @@
 package config
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -115,6 +116,44 @@ func LoadBotUserConfig(configPath string) (*BotUserConfig, error) {
 	return &cfg, nil
 }
 
+// SaveBotNodeConfig persists the given node UUIDs to the bot node config file.
+// Entries already present in the file are always preserved: a UUID Komari no
+// longer reports on a given fetch is kept rather than deleted, so per-node
+// settings for stale nodes survive a node-list refresh that does not include
+// them. UUIDs seen for the first time are added with an empty BotNodeOptions
+// entry. The resulting JSON has its object keys emitted in sorted order by
+// encoding/json, keeping the file deterministic across writes. The path is
+// supplied by the caller (typically global.ConfigPath.BotNodeConfig).
+func SaveBotNodeConfig(configPath string, uuids []string) error {
+	// Start from whatever is already on disk so nothing is dropped. An empty or
+	// missing file is treated as an empty map.
+	members := make(BotNodeMembers)
+	if data, err := os.ReadFile(configPath); err == nil && len(bytes.TrimSpace(data)) > 0 {
+		if err := json.Unmarshal(data, &members); err != nil {
+			return fmt.Errorf("failed to parse existing bot node config %s: %w", configPath, err)
+		}
+	}
+
+	// Add every currently-fetched UUID, but never overwrite an entry that is
+	// already configured.
+	for _, uuid := range uuids {
+		if _, ok := members[uuid]; !ok {
+			members[uuid] = BotNodeOptions{}
+		}
+	}
+
+	data, err := json.MarshalIndent(members, "", "    ")
+	if err != nil {
+		return fmt.Errorf("failed to marshal bot node config: %w", err)
+	}
+	data = append(data, '\n')
+
+	if err := os.WriteFile(configPath, data, 0o644); err != nil {
+		return fmt.Errorf("failed to write bot node config %s: %w", configPath, err)
+	}
+	return nil
+}
+
 // IsDebugMode returns whether debug mode is enabled.
 func IsDebugMode() bool {
 	if C_globalConfig == nil {
diff --git a/config/variables.go b/config/variables.go
index 44b50c7..d5c4a60 100644
--- a/config/variables.go
+++ b/config/variables.go
@@ -170,3 +170,16 @@ type BotUserConfig struct {
 }
 
 var C_botUserConfig *BotUserConfig
+
+// BotNodeOptions holds per-node options stored in bot_node_config.json. The
+// struct is currently empty; per-node settings can be added here later without
+// invalidating existing files.
+type BotNodeOptions struct {
+}
+
+// BotNodeMembers maps a node UUID (as reported by Komari) to its per-node
+// options. A plain struct value marshals to an empty JSON object, so
+// bot_node_config.json reads like:
+//
+//	{"<uuid1>": {}, "<uuid2>": {}}
+type BotNodeMembers map[string]BotNodeOptions
diff --git a/internal/komari/client.go b/internal/komari/client.go
index 80460a6..542079a 100644
--- a/internal/komari/client.go
+++ b/internal/komari/client.go
@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"nukumizu-backend/config"
+	"nukumizu-backend/global"
 	"nukumizu-backend/internal/node"
 	"nukumizu-backend/postLog"
 )
@@ -225,6 +226,20 @@ func (c *Client) FetchNodes() ([]NodeInfo, error) {
 		nodes = append(nodes, n)
 	}
 
+	// Persist the fetched node UUIDs to bot_node_config.json on every fetch
+	// (startup login, WebSocket reconnect and periodic refresh all funnel
+	// through FetchNodes) so the file always reflects the nodes Komari
+	// currently manages. A persistence failure is only logged: the node data
+	// itself was fetched successfully and must not be discarded over a disk
+	// write problem.
+	uuids := make([]string, len(nodes))
+	for i, n := range nodes {
+		uuids[i] = n.UUID
+	}
+	if err := config.SaveBotNodeConfig(global.ConfigPath.BotNodeConfig, uuids); err != nil {
+		postLog.Warning("Failed to save bot node config: " + err.Error())
+	}
+
 	postLog.Info(fmt.Sprintf("Fetched %d nodes from Komari", len(nodes)))
 	return nodes, nil
 }