diff --git a/src/commands.ts b/src/commands.ts
index 61b7b74..db238aa 100644
--- a/src/commands.ts
+++ b/src/commands.ts
@@ -24,8 +24,8 @@ export async function renderThinkingPicker(
   let variants: string[] = []
   if (model) {
     try {
-      const list = await ctx.model.list()
-      const found = list.data.find(
+      const list = await ctx.model?.list?.()
+      const found = list?.data?.find(
         (m) => m.providerID === model.providerID && m.id === model.id,
       )
       variants = (found?.variants ?? []).map((v) => v.id).slice(0, 12)
@@ -57,8 +57,8 @@ export async function renderModelPicker(
   messageID?: number,
   current?: string,
 ): Promise<void> {
-  const res = await ctx.model.list()
-  const models = res.data
+  const res = await ctx.model?.list?.()
+  const models = (res?.data ?? [])
     .filter((m) => m.status !== "deprecated")
     .map((m) => ({ label: `${m.providerID}/${m.id}`, key: `${m.providerID}|${m.id}` }))
     .filter((m) => m.key.length <= 56)
diff --git a/src/index.ts b/src/index.ts
index 041a4fb..1ca92f0 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -105,10 +105,12 @@ export default Plugin.define({
         }
         const loadLimits = async (): Promise<void> => {
           try {
-            const list = await ctx.model.list()
-            for (const m of list.data) {
-              const limit = m.limit?.context
-              if (limit) modelLimits.set(`${m.providerID}/${m.id}`, limit)
+            const list = await ctx.model?.list?.()
+            if (list?.data) {
+              for (const m of list.data) {
+                const limit = m.limit?.context
+                if (limit) modelLimits.set(`${m.providerID}/${m.id}`, limit)
+              }
             }
             limitsLoaded = true
           } catch (err) {
diff --git a/src/loop.ts b/src/loop.ts
index 19f8f9c..64a32e1 100644
--- a/src/loop.ts
+++ b/src/loop.ts
@@ -1,4 +1,4 @@
-import { closeSync, mkdirSync, openSync, readFileSync, unlinkSync, writeSync, existsSync } from "node:fs"
+import { closeSync, mkdirSync, openSync, readFileSync, unlinkSync, writeFileSync, writeSync, existsSync } from "node:fs"
 import { homedir } from "node:os"
 import { join } from "node:path"
 import { TelegramBot, type TelegramConfig, type TelegramMessage, type TelegramUpdate } from "./bot.js"
@@ -41,7 +41,7 @@ const readLease = (): LeaseData | undefined => {
 }
 
 const writeLease = (data: LeaseData): void => {
-  writeSync(openSync(LEASE_FILE, "w"), JSON.stringify(data))
+  writeFileSync(LEASE_FILE, JSON.stringify(data))
 }
 
 export interface Lease {
@@ -62,8 +62,11 @@ export function acquireLease(initialOffset = 0): Lease {
   for (let attempt = 0; attempt < 3; attempt++) {
     try {
       const fd = openSync(LEASE_FILE, "wx")
-      writeSync(fd, JSON.stringify({ pid: me, at: Date.now(), offset } satisfies LeaseData))
-      closeSync(fd)
+      try {
+        writeSync(fd, JSON.stringify({ pid: me, at: Date.now(), offset } satisfies LeaseData))
+      } finally {
+        closeSync(fd)
+      }
       return makeHeld()
     } catch (err) {
       if ((err as NodeJS.ErrnoException).code !== "EEXIST") throw err