Slackfmt

slackfmt

Convert markdown (or HTML) to Slack's native rich text format and copy to clipboard. When pasted into Slack, all formatting (bold, italic, lists, code blocks, links, blockquotes) is preserved.

When to Use

• User wants to format a message for Slack
• User wants to copy formatted content to clipboard for pasting into Slack
• User has markdown, HTML, or Quill Delta content destined for Slack
• User asks to "copy to Slack", "format for Slack", or "paste into Slack"

Slack limitations: Headings are converted to bold text. Only basic formatting is supported (bold, italic, strikethrough, code, links, lists, blockquotes, code blocks).

CLI Usage

# Pipe content to slackfmt (copies to clipboard by default)
echo "**bold** and _italic_" | npx @slackfmt/cli@latest

# Specify input format explicitly
echo "<b>hello</b>" | npx @slackfmt/cli@latest -f html

Flags:

• -f, --format — Input format: markdown (default), html, slack-html, quill-delta
• --stdout — Print Quill Delta JSON to stdout instead of copying to clipboard

Format auto-detection: If no -f flag, slackfmt detects JSON (quill-delta), HTML tags (html), or falls back to markdown.

Instructions

1. Compose the content as markdown in an echo or printf command
2. Pipe it to npx @slackfmt/cli@latest
3. The formatted content is copied to the system clipboard
4. User can paste directly into Slack with formatting preserved

Example

echo '- **Performance**
  - Dashboard speed improvements
  - 90% faster queries
- **Bug Fixes**
  - Fixed mobile layout issue' | npx @slackfmt/cli@latest

Tips

• Use * for bold, _ for italic (Slack conventions)
• Nested lists work — use 2-space indentation
• Links: [text](url) becomes clickable in Slack
• Code blocks: use triple backticks
• Blockquotes: use >
• Headings (#, ##, etc.) are converted to bold paragraphs