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boxel-flavored-markdown

Use when authoring or editing Boxel Flavored Markdown (BFM) content — content fields rendered as rich markdown with :card/::card directives, mermaid diagrams…

Skill by cardstack

IndexedMIT★ 1
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Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/cardstack-boxel-flavored-markdown

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

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About

Use when authoring or editing Boxel Flavored Markdown (BFM) content — content fields rendered as rich markdown with :card/::card directives, mermaid diagrams, etc.

Use cases: documents, writing

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What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
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Install scripts
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Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/boxel-flavored-markdown

What's inside

Skill name
boxel-flavored-markdown
Description
Use when authoring or editing Boxel Flavored Markdown (BFM) content — content fields rendered as rich markdown with :card/::card directives, mermaid diagrams, etc.
License
MIT
Instructions
35 lines in SKILL.md · view on GitHub

Files (7)

  • SKILL.md
  • authoring-notes.md · references/
  • base-syntax.md · references/
  • bfm-extensions-beyond-commonmarkgfm.md · references/
  • card-directives-the-boxel-extension.md · references/
  • quick-reference.md · references/
  • where-bfm-is-used.md · references/

SKILL.md (first lines)

# Boxel Flavored Markdown (BFM)

_BFM reference: render surfaces, base syntax, :card/::card directives, mermaid, math ($...$ / $$...$$), alerts, footnotes, and code highlighting._

BFM is the markdown dialect Boxel reads and writes. It extends CommonMark + GitHub Flavored Markdown with:

- Card directives (`:card[URL]`, `::card[URL | spec]`) for embedding cards
- Mermaid diagrams in fenced code blocks
- LaTeX math via `$...$` / `$$...$$` (KaTeX)
- GFM alerts (`> [!NOTE]`, `> [!WARNING]`, etc.)
- Footnotes, extended tables, heading IDs
- Monaco-powered syntax highlighting for fenced code blocks

## Pair with

- **`boxel-markdown-format`** — when you're generating BFM as the *output* of a `static markdown` template.
- **`boxel`** — for the surrounding CardDef when the content is a card field: `RichMarkdownField` when it embeds cards (a plain `MarkdownField` never resolves `:card[]` directives).

## Don't use for

- Plain CommonMark or GFM content with no Boxel-specific directives (no extra skill needed).
- HTML-emitting markdown (BFM is plain-text; the runtime renders it).

---

## Sections (load on demand)

- `references/where-bfm-is-used.md` — Where BFM is used
- `references/base-syntax.md` — Base syntax
- `references/bfm-extensions-beyond-commonmarkgfm.md` — BFM extensions beyond CommonMark/GFM
- `references/card-directives-the-boxel-extension.md` — Card directives (the Boxel extension)
- `references/authoring-notes.md` — Authoring notes
- `references/quick-reference.md` — Quick reference

From cardstack/boxel-skills, MIT.

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Last commit (this folder)
Oct 16, 2026 (12 days ago)
Last release
Oct 23, 2026 (5 days ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

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Cite this page

boxel-flavored-markdown skill. Agent Mart. https://agentmart.dev/skills/cardstack-boxel-flavored-markdown (last updated 2026-10-24)