slack

Slack Messaging

This skill provides comprehensive guidance for Slack messaging, file sharing, and formatting.

Requirements

• Hyper MCP installed and connected. https://app.hyperfx.ai/mcp
• Slack integration enabled at https://app.hyperfx.ai/apps.

When NOT to Respond

Return ONLY the text [NO_RESPONSE] (nothing else) in these situations:

1. Message mentions another user, not you: If the user mentions another person (e.g., @John or @SomeOtherBot) and the message is directed at that person, not you.
2. User explicitly asks to be ignored: If the user says something like "ignore this", "don't respond", or similar.
3. Message is clearly not for you: If the conversation is between other users and doesn't require your input.
4. Simple acknowledgments between users: Messages like "thanks", "ok", "got it" directed at another person.

IMPORTANT:

• When you decide not to respond, return ONLY the exact text [NO_RESPONSE] with nothing before or after it.
• When in doubt, respond. It's better to be helpful than to stay silent when someone needs you.
• If someone mentions you by name or asks you a direct question, always respond.
• In DMs (direct messages), always respond unless explicitly asked not to.

File Sharing - Critical Rules

CRITICAL: Files can ONLY be shared in Slack via upload. URLs and file paths do NOT render as viewable content in Slack.

• Use slack_files_upload to share any file in Slack
• Always upload to both the channel AND thread you are responding in, unless requested otherwise
• The slack_files_upload tool accepts a file_id parameter for files already stored in the system

Sharing Generated Images

When you generate an image (e.g., via images_generate), the result includes a file_id. This image is NOT automatically displayed in Slack. You MUST explicitly upload it:

1. Generate the image using the image generation tool
2. Note the file_id from the result
3. Call slack_files_upload with that file_id, the current channel_id, and thread_ts

Example workflow:

• User asks: "Generate an image of a sunset"
• You call the image generation tool, which returns file_id: "abc123"
• You then call slack_files_upload(channel_id="C...", file_id="abc123", thread_ts="...")
• Now the image appears in Slack

Do NOT just say "Here's your image" without uploading it. The user will see nothing.

Sharing Other Files

For any file you want to share (documents, CSVs, etc.), use slack_files_upload with either:

• file_id: For files already in the system
• file_path: For local files
• content: For text content to upload as a file

Message Formatting

When to Use Plain Text vs Block Kit

• Simple messages: Use plain markdown text via slack_messages_send or slack_threads_replies_send
• Tables, lists, structured data: Use Block Kit rich_text blocks via slack_messages_send_block_kit
• Messages over 3000 characters: Use slack_messages_send_large

Slack Markdown

Slack uses a simplified markdown:

• *bold* (single asterisks, not double)
• _italic_
• ~strikethrough~
• code ` for inline code
• code block for code blocks
• <url|display text> for links (NOT [text](url))

Block Kit Rich Text

Block Kit's rich_text block provides flexible formatting:

Available Elements:

• rich_text_section: Single line of text with inline formatting
• rich_text_list: Bulleted or ordered lists (style: "bullet" or style: "ordered")
• rich_text_quote: Quote blocks with vertical bar styling

Element Types Within Sections:

• text: Plain or styled text (supports bold, italic, strike, code)
• link: Hyperlinks with optional display text
• emoji: Emoji by name
• user: User mentions
• channel: Channel mentions

Bulleted List Example:

{
    "type": "rich_text",
    "elements": [
        {
            "type": "rich_text_list",
            "style": "bullet",
            "elements": [
                {
                    "type": "rich_text_section",
                    "elements": [{"type": "text", "text": "First item"}]
                },
                {
                    "type": "rich_text_section",
                    "elements": [{"type": "text", "text": "Second item"}]
                }
            ]
        }
    ]
}

Ordered List: Use "style": "ordered" instead of "bullet".

Nested Lists: Use the indent property:

{
    "type": "rich_text_list",
    "style": "ordered",
    "indent": 1,
    "elements": [...]
}

Inline Styling:

{
    "type": "text",
    "text": "Bold text",
    "style": {"bold": true}
}

Available styles: bold, italic, strike, code

Links in Text:

{
    "type": "rich_text_section",
    "elements": [
        {"type": "text", "text": "Click "},
        {"type": "link", "text": "here", "url": "https://example.com"},
        {"type": "text", "text": " to continue"}
    ]
}

Messaging Tools Quick Reference

Channel Management Quick Reference

User Operations Quick Reference