openclaw-openclaw/docs/concepts/markdown-formatting.md

summary, read_when, title

summary	read_when	title
Markdown formatting pipeline for outbound channels	You are changing markdown formatting or chunking for outbound channels You are adding a new channel formatter or style mapping You are debugging formatting regressions across channels	Markdown formatting

OpenClaw converts outbound Markdown into a shared intermediate representation (IR) before rendering channel-specific output. The IR keeps plain text plus style/link spans, so one parse step feeds every channel and chunking never splits formatting mid-span.

Pipeline

1. Parse Markdown into IR (markdownToIR) - plain text plus style spans (bold, italic, strikethrough, code, code block, spoiler, blockquote, heading 1-6) and link spans. Offsets are UTF-16 code units so Signal style ranges align with its API directly. Tables parse only when the channel opts into a table mode.
2. Chunk the IR (chunkMarkdownIR / renderMarkdownIRChunksWithinLimit)
   • splitting happens on IR text before rendering, so inline styles and links are sliced per chunk instead of breaking across a boundary.
3. Render per channel (renderMarkdownWithMarkers) - a style-marker map turns spans into the channel's native markup.

Channel	Renderer	Notes
Slack	mrkdwn tokens (*bold*, _italic_, `code`, code fences)	Links become <url|label>; autolink disabled during parse to avoid double-linking
Telegram	HTML tags (<b>, <i>, <s>, <code>, <pre><code>, <a href>, <tg-spoiler>)	Also supports rich-message tables and headings (<h1>-<h6>) when richMessages is on
Signal	plain text + text-style ranges	Links render as label (url) when the label differs from the URL
Discord, WhatsApp, iMessage, Microsoft Teams, and other channels	plain text	No IR-based styling; Markdown table conversion still runs via convertMarkdownTables

IR example

Input Markdown:

Hello **world** - see [docs](https://docs.openclaw.ai).

IR (schematic):

{
  "text": "Hello world - see docs.",
  "styles": [{ "start": 6, "end": 11, "style": "bold" }],
  "links": [{ "start": 19, "end": 23, "href": "https://docs.openclaw.ai" }]
}

Table handling

markdown.tables controls how a channel converts Markdown tables, per channel and optionally per account:

Mode	Behavior
code	Render as an aligned ASCII table inside a code block (fallback default)
bullets	Convert each row into label: value bullet points
block	Keep native tables where the transport supports them; falls back to code otherwise
off	Disable table parsing; raw table text passes through unchanged

Per-channel plugin defaults: Signal, WhatsApp, and Matrix default to bullets; Mattermost defaults to off; Telegram defaults to block (which resolves to code unless the account has richMessages enabled). Any channel without an explicit plugin default falls back to code.

channels:
  discord:
    markdown:
      tables: code
    accounts:
      work:
        markdown:
          tables: off

Chunking rules

• Chunk limits come from channel adapters/config and apply to IR text, not rendered output.
• Fenced code blocks are kept as one block with a trailing newline so channels render the closing fence correctly.
• List and blockquote prefixes are part of the IR text, so chunking never splits mid-prefix.
• Inline styles never split across chunks; the renderer reopens an open style at the start of the next chunk.

See Streaming and chunking for chunk-boundary and delivery behavior across channels.

Link policy

• Slack: [label](url) -> <url|label>; bare URLs stay bare.
• Telegram: [label](url) -> <a href="url">label</a> (HTML parse mode).
• Signal: [label](url) -> label (url) unless the label already matches the URL.

Spoilers

Spoiler markers (||spoiler||) are parsed for Signal (mapped to SPOILER style ranges) and Telegram (mapped to <tg-spoiler>). Other channels treat ||...|| as plain text.

Adding or updating a channel formatter

1. Parse once with markdownToIR(...), passing channel-appropriate options (autolink, headingStyle, blockquotePrefix, tableMode).
2. Render with renderMarkdownWithMarkers(...) and a style-marker map (or custom style-range logic for transports like Signal).
3. Chunk with chunkMarkdownIR(...) or renderMarkdownIRChunksWithinLimit(...) before rendering each chunk.
4. Wire the adapter to call the new chunker and renderer from the outbound send path.
5. Test with format tests plus an outbound delivery test if the channel chunks.

Common gotchas

• Slack angle-bracket tokens (<@U123>, <#C123>, <https://...>) must survive escaping; raw HTML still needs to be escaped safely.
• Telegram HTML requires escaping text outside tags to avoid broken markup.
• Signal style ranges use UTF-16 offsets, not code-point offsets.
• Preserve trailing newlines on fenced code blocks so the closing marker lands on its own line.

Related

Outbound streaming behavior, chunk boundaries, and channel-specific delivery. What the model sees before the conversation, including injected workspace files.