channel-post

Channel Post

Compose and post formatted content to a Telegram channel with correct formatting.

Steps

1. Identify target channel:

   • chats(action="list") to find the channel
   • Channel chat_id is a negative number (e.g., -1001234567890) or @username

2. Compose content with the user:

   • Draft the message text
   • Apply MarkdownV2 formatting (see escaping rules below)
   • Determine if media attachments are needed

3. Handle media attachments (if any):

   • Photo with caption: media(action="send_photo", chat_id="...", file_path="...", caption="...") -- caption goes WITH the photo, not as a separate message
   • Document: media(action="send_document", chat_id="...", file_path="...")
   • Multiple photos: send as media group, first photo carries the caption

4. Split long messages if content exceeds 4096 characters:

   • Split at paragraph boundaries (double newline) to preserve readability
   • Each chunk must be independently valid MarkdownV2 (no unclosed formatting)
   • Send chunks sequentially with the same parse_mode

5. Send and verify:

   • messages(action="send", chat_id="<channel>", text="<content>", parse_mode="MarkdownV2")
   • Verify the message appears correctly in the channel
   • If formatting breaks, check the escaping rules below

MarkdownV2 Escaping Rules

All these characters MUST be escaped with \ when used as literal text (outside formatting markup):

_ * [ ] ( ) ~ ` > # + - = | { } . !

Common patterns

Intent	Correct MarkdownV2
Bold text	*bold*
Italic text	_italic_
Code inline	`code`
Code block	```language\ncode\n```
Link	[text](https://url)
Literal dot in "v2.0"	v2\.0
Literal dash in list	\- item
Price "$9.99"	\$9\.99
Exclamation "Done!"	Done\!
Parenthetical "(note)"	\(note\)
Hashtag "#topic"	\#topic

Formatting inside formatting

When nesting, the inner delimiter must also be escaped:

• Bold italic: *_bold italic_* -- the _ inside *...* does NOT need escaping
• But literal _ inside bold: *score\_value* -- MUST escape

Frequent mistakes

• Forgetting to escape . in URLs used as plain text (not inside [](...))
• Forgetting to escape ! at end of sentences
• Forgetting to escape - in bulleted lists (use \- or switch to HTML <li>)
• Unescaped ( ) in regular text (Telegram interprets them as link syntax)

When to Use

• Publishing announcements, updates, or newsletters to a Telegram channel
• Posting formatted content (code snippets, tables, lists) to channels
• Sending content with images or documents to channels
• Any message that needs careful MarkdownV2 formatting