fix(telegram): gate native fetch to bun

CHANGELOG.md

@@ -108,6 +108,7 @@
 - Telegram: isolate forum topic transcripts per thread and validate Gemini turn ordering in multi-topic sessions. Thanks @hsrvc for PR #407.
 - Telegram: render Telegram-safe HTML for outbound formatting and fall back to plain text on parse errors. Thanks @RandyVentures for PR #435.
 - Telegram: force grammY to use native fetch under Bun for BAN compatibility (avoids TLS chain errors).
+- Telegram: keep grammY default fetch on Node; only override under Bun to avoid Node 24 regressions.
 - iMessage: ignore disconnect errors during shutdown (avoid unhandled promise rejections). Thanks @antons for PR #359.
 - Messages: stop defaulting ack reactions to 👀 when identity emoji is missing.
 - Auto-reply: require slash for control commands to avoid false triggers in normal text.

src/telegram/bot.ts

@@ -152,11 +152,11 @@ export function createTelegramBot(opts: TelegramBotOptions) {
     },
   };
   const fetchImpl = resolveTelegramFetch(opts.proxyFetch);
-  const client: ApiClientOptions = {
-    fetch: fetchImpl as unknown as ApiClientOptions["fetch"],
-  };
+  const client: ApiClientOptions | undefined = fetchImpl
+    ? { fetch: fetchImpl as unknown as ApiClientOptions["fetch"] }
+    : undefined;
 
-  const bot = new Bot(opts.token, { client });
+  const bot = new Bot(opts.token, client ? { client } : undefined);
   bot.api.config.use(apiThrottler());
   bot.use(sequentialize(getTelegramSequentialKey));
 

src/telegram/fetch.ts

@@ -1,6 +1,11 @@
-// BAN compatibility: force native fetch to avoid grammY's node-fetch shim under Bun.
-export function resolveTelegramFetch(proxyFetch?: typeof fetch): typeof fetch {
-  const fetchImpl = proxyFetch ?? globalThis.fetch;
+// BAN compatibility: force native fetch under Bun; keep grammY defaults on Node.
+export function resolveTelegramFetch(
+  proxyFetch?: typeof fetch,
+): typeof fetch | undefined {
+  if (proxyFetch) return proxyFetch;
+  const isBun = "Bun" in globalThis || Boolean(process?.versions?.bun);
+  if (!isBun) return undefined;
+  const fetchImpl = globalThis.fetch;
   if (!fetchImpl) {
     throw new Error("fetch is not available; set telegram.proxy in config");
   }

src/telegram/send.ts

@@ -112,11 +112,10 @@ export async function sendMessageTelegram(
   const chatId = normalizeChatId(to);
   // Use provided api or create a new Bot instance. The nullish coalescing
   // operator ensures api is always defined (Bot.api is always non-null).
+  const fetchImpl = resolveTelegramFetch();
   const api =
     opts.api ??
-    new Bot(token, {
-      client: { fetch: resolveTelegramFetch() },
-    }).api;
+    new Bot(token, fetchImpl ? { client: { fetch: fetchImpl } } : undefined).api;
   const mediaUrl = opts.mediaUrl?.trim();
 
   // Build optional params for forum topics and reply threading.
@@ -270,11 +269,10 @@ export async function reactMessageTelegram(
   const token = resolveToken(opts.token, account);
   const chatId = normalizeChatId(String(chatIdInput));
   const messageId = normalizeMessageId(messageIdInput);
+  const fetchImpl = resolveTelegramFetch();
   const api =
     opts.api ??
-    new Bot(token, {
-      client: { fetch: resolveTelegramFetch() },
-    }).api;
+    new Bot(token, fetchImpl ? { client: { fetch: fetchImpl } } : undefined).api;
   const request = createTelegramRetryRunner({
     retry: opts.retry,
     configRetry: account.config.retry,

src/telegram/webhook-set.ts

@@ -7,9 +7,11 @@ export async function setTelegramWebhook(opts: {
   secret?: string;
   dropPendingUpdates?: boolean;
 }) {
-  const bot = new Bot(opts.token, {
-    client: { fetch: resolveTelegramFetch() },
-  });
+  const fetchImpl = resolveTelegramFetch();
+  const bot = new Bot(
+    opts.token,
+    fetchImpl ? { client: { fetch: fetchImpl } } : undefined,
+  );
   await bot.api.setWebhook(opts.url, {
     secret_token: opts.secret,
     drop_pending_updates: opts.dropPendingUpdates ?? false,
@@ -17,8 +19,10 @@ export async function setTelegramWebhook(opts: {
 }
 
 export async function deleteTelegramWebhook(opts: { token: string }) {
-  const bot = new Bot(opts.token, {
-    client: { fetch: resolveTelegramFetch() },
-  });
+  const fetchImpl = resolveTelegramFetch();
+  const bot = new Bot(
+    opts.token,
+    fetchImpl ? { client: { fetch: fetchImpl } } : undefined,
+  );
   await bot.api.deleteWebhook();
 }