fix: chunk telegram markdown sends

CHANGELOG.md

@@ -23,6 +23,7 @@ Docs: https://docs.openclaw.ai
 
 - Config: log the "newer OpenClaw" version warning once per process instead of once per config snapshot read. (#75927) Thanks @romneyda.
 - Telegram/message actions: treat benign delete-message 400s as no-op warnings instead of runtime errors, so stale or already-removed messages do not create noisy delete failures. Fixes #73726. Thanks @Avicennasis.
+- Telegram: split long default markdown sends and media follow-up text into safe HTML chunks, so outbound messages over Telegram's limit no longer fail as one oversized Bot API request. Fixes #75868. Thanks @zhengsx.
 - Gateway/chat history: merge Claude CLI transcript imports for Anthropic-routed sessions that still have a Claude CLI binding, so local chat history does not hide CLI JSONL turns. Fixes #75850. Thanks @alfredjbclaw.
 - Media: trim serialized JSON suffixes after local `MEDIA:` directive file extensions, so generated-image metadata cannot pollute the parsed media path and cause false `ENOENT` delivery failures. Fixes #75182. Thanks @TnzGit and @hclsys.
 - Cron: make scheduler reload schedule comparison tolerate malformed persisted jobs, so one bad cron entry no longer aborts the whole tick. Fixes #75886. Thanks @samfox-ai.

extensions/telegram/src/send.test.ts

@@ -843,6 +843,46 @@ describe("sendMessageTelegram", () => {
     expect(res.messageId).toBe("71");
   });
 
+  it("chunks long default markdown media follow-up text", async () => {
+    const chatId = "123";
+    const longText = `**${"A".repeat(5000)}**`;
+
+    const sendPhoto = vi.fn().mockResolvedValue({
+      message_id: 72,
+      chat: { id: chatId },
+    });
+    const sendMessage = vi
+      .fn()
+      .mockResolvedValueOnce({ message_id: 73, chat: { id: chatId } })
+      .mockResolvedValueOnce({ message_id: 74, chat: { id: chatId } });
+    const api = { sendPhoto, sendMessage } as unknown as {
+      sendPhoto: typeof sendPhoto;
+      sendMessage: typeof sendMessage;
+    };
+
+    mockLoadedMedia({
+      buffer: Buffer.from("fake-image"),
+      contentType: "image/jpeg",
+      fileName: "photo.jpg",
+    });
+
+    const res = await sendMessageTelegram(chatId, longText, {
+      cfg: TELEGRAM_TEST_CFG,
+      token: "tok",
+      api,
+      mediaUrl: "https://example.com/photo.jpg",
+    });
+
+    expect(sendPhoto).toHaveBeenCalledWith(chatId, expect.anything(), {
+      caption: undefined,
+    });
+    expect(sendMessage).toHaveBeenCalledTimes(2);
+    expect(sendMessage.mock.calls.every((call) => call[2]?.parse_mode === "HTML")).toBe(true);
+    expect(sendMessage.mock.calls.every((call) => String(call[1] ?? "").length <= 4000)).toBe(true);
+    expect(sendMessage.mock.calls.map((call) => String(call[1] ?? "")).join("")).toContain("<b>");
+    expect(res.messageId).toBe("74");
+  });
+
   it("uses caption when text is within 1024 char limit", async () => {
     const chatId = "123";
     const shortText = "B".repeat(1024);
@@ -1898,6 +1938,41 @@ describe("sendMessageTelegram", () => {
     expect(res.messageId).toBe("91");
   });
 
+  it("chunks long default markdown text and keeps buttons on the last chunk only", async () => {
+    const chatId = "123";
+    const markdownText = `**${"A".repeat(5000)}**`;
+
+    const sendMessage = vi
+      .fn()
+      .mockResolvedValueOnce({ message_id: 90, chat: { id: chatId } })
+      .mockResolvedValueOnce({ message_id: 91, chat: { id: chatId } });
+    const api = { sendMessage } as unknown as { sendMessage: typeof sendMessage };
+
+    const res = await sendMessageTelegram(chatId, markdownText, {
+      cfg: TELEGRAM_TEST_CFG,
+      token: "tok",
+      api,
+      buttons: [[{ text: "OK", callback_data: "ok" }]],
+    });
+
+    expect(sendMessage).toHaveBeenCalledTimes(2);
+    const firstCall = sendMessage.mock.calls[0];
+    const secondCall = sendMessage.mock.calls[1];
+    expect(firstCall).toBeDefined();
+    expect(secondCall).toBeDefined();
+    expect(String(firstCall[1] ?? "").length).toBeLessThanOrEqual(4000);
+    expect(String(secondCall[1] ?? "").length).toBeLessThanOrEqual(4000);
+    expect(firstCall[2]?.parse_mode).toBe("HTML");
+    expect(secondCall[2]?.parse_mode).toBe("HTML");
+    expect(String(firstCall[1] ?? "")).toMatch(/^<b>[\s\S]*<\/b>$/);
+    expect(String(secondCall[1] ?? "")).toMatch(/^<b>[\s\S]*<\/b>$/);
+    expect(firstCall[2]?.reply_markup).toBeUndefined();
+    expect(secondCall[2]?.reply_markup).toEqual({
+      inline_keyboard: [[{ text: "OK", callback_data: "ok" }]],
+    });
+    expect(res.messageId).toBe("91");
+  });
+
   it("preserves caller plain-text fallback across chunked html parse retries", async () => {
     const chatId = "123";
     const htmlText = `<b>${"A".repeat(5000)}</b>`;

extensions/telegram/src/send.ts

@@ -720,10 +720,11 @@ export async function sendMessageTelegram(
   };
 
   const buildChunkedTextPlan = (rawText: string, context: string): TelegramTextChunk[] => {
+    const htmlText = renderHtmlText(rawText);
     const fallbackText = opts.plainText ?? rawText;
     let htmlChunks: string[];
     try {
-      htmlChunks = splitTelegramHtmlChunks(rawText, 4000);
+      htmlChunks = splitTelegramHtmlChunks(htmlText, 4000);
     } catch (error) {
       logVerbose(
         `telegram ${context} failed HTML chunk planning, retrying as plain text: ${formatErrorMessage(
@@ -951,14 +952,7 @@ export async function sendMessageTelegram(
     // If text was too long for a caption, send it as a separate follow-up message.
     // Use HTML conversion so markdown renders like captions.
     if (needsSeparateText && followUpText) {
-      if (textMode === "html") {
-        const textResult = await sendChunkedText(followUpText, "text follow-up send");
-        return { messageId: textResult.messageId, chatId: resolvedChatId };
-      }
-      const textResult = await sendTelegramTextChunks(
-        [{ plainText: followUpText, htmlText: renderHtmlText(followUpText) }],
-        "text follow-up send",
-      );
+      const textResult = await sendChunkedText(followUpText, "text follow-up send");
       return { messageId: textResult.messageId, chatId: resolvedChatId };
     }
 
@@ -968,15 +962,7 @@ export async function sendMessageTelegram(
   if (!text || !text.trim()) {
     throw new Error("Message must be non-empty for Telegram sends");
   }
-  let textResult: { messageId: string; chatId: string };
-  if (textMode === "html") {
-    textResult = await sendChunkedText(text, "text send");
-  } else {
-    textResult = await sendTelegramTextChunks(
-      [{ plainText: opts.plainText ?? text, htmlText: renderHtmlText(text) }],
-      "text send",
-    );
-  }
+  const textResult = await sendChunkedText(text, "text send");
   recordChannelActivity({
     channel: "telegram",
     accountId: account.accountId,