qwen-code/docs/users/features/markdown-rendering.md
Dragon fad5ae0bab
docs: document inline terminal image previews (#8656)
* docs: document inline terminal images

* docs: clarify inline image behavior

* docs: scope terminal image limits

* docs: clarify IM image delivery support

* docs: separate terminal image guidance
2026-08-21 07:24:20 +00:00

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Markdown Rendering

Qwen Code renders common Markdown structures directly in the TUI so model answers are easier to scan without leaving the terminal. The renderer is designed to keep the original source reachable, especially for visual blocks such as Mermaid diagrams and LaTeX math.

Render and Raw Modes

By default, Markdown is shown in render mode. Supported blocks render as visual previews where possible:

  • Mermaid fenced code blocks
  • Markdown tables
  • task lists
  • blockquotes
  • inline and block LaTeX math
  • fenced code blocks with syntax highlighting

Press Alt/Option+M to toggle the current session between modes. On macOS, the terminal must send Option as Meta for this shortcut; otherwise Option+M is treated as normal text input.

  • render: show rich terminal previews for supported Markdown.
  • raw: show source-oriented Markdown for visual blocks such as Mermaid, tables, and LaTeX.

To start Qwen Code in raw mode by default, set ui.renderMode:

{
  "ui": {
    "renderMode": "raw"
  }
}

Accepted values are "render" and "raw". The shortcut only changes the current session view; it does not rewrite your settings file.

Assistant and Tool Images

Image parts use a separate TUI display path and behave the same in Markdown render and raw modes. See Terminal Images for terminal support, fallbacks, limits, channel delivery, and session-history behavior.

Mermaid

Fenced mermaid code blocks render visually in render mode. The TUI uses a layered strategy:

  1. If enabled and supported, Qwen Code asks Mermaid CLI (mmdc) to render the diagram to a PNG and sends it to the terminal image protocol.
  2. If terminal images are unavailable but chafa is installed, the same PNG can be converted to ANSI block graphics.
  3. Otherwise, Qwen Code falls back to a terminal wireframe or compact text preview.
  4. If a Mermaid diagram type cannot be previewed, Qwen Code shows the original fenced source instead of hiding it behind a placeholder.

Mermaid image rendering is disabled by default because it requires external renderers and terminal image support. Enable it with:

QWEN_CODE_MERMAID_IMAGE_RENDERING=1 qwen

Optional environment variables:

Variable Description
QWEN_CODE_MERMAID_IMAGE_RENDERING=1 Enables external Mermaid image rendering.
QWEN_CODE_DISABLE_MERMAID_IMAGES=1 Disables Mermaid image rendering even when enabled elsewhere.
QWEN_CODE_MERMAID_IMAGE_PROTOCOL=kitty Forces Kitty protocol output. Useful for terminals such as Kitty and Ghostty.
QWEN_CODE_MERMAID_IMAGE_PROTOCOL=iterm2 Requests iTerm2 inline images. Interactive TUI rendering falls back to text/ANSI.
QWEN_CODE_MERMAID_IMAGE_PROTOCOL=off Disables terminal image protocols and allows text or chafa fallback.
QWEN_CODE_MERMAID_MMD_CLI=/path/to/mmdc Uses a specific Mermaid CLI executable.
QWEN_CODE_MERMAID_ALLOW_NPX=1 Allows Qwen Code to run npx @mermaid-js/mermaid-cli when mmdc is not installed.
QWEN_CODE_MERMAID_ALLOW_LOCAL_RENDERERS=1 Allows project-local renderer binaries under node_modules/.bin.
QWEN_CODE_MERMAID_RENDER_WIDTH=1200 Overrides the PNG render width.
QWEN_CODE_MERMAID_RENDER_TIMEOUT_MS=10000 Overrides the external render timeout, capped at 60000 ms.
QWEN_CODE_MERMAID_CELL_ASPECT_RATIO=0.5 Adjusts image row fitting for terminal font cell geometry.

The first image render can be slow, especially when npx needs to resolve or download Mermaid CLI. During streaming, Qwen Code shows a bounded text preview and attempts image rendering only after the model response is complete.

Mermaid Source Copy

Every rendered Mermaid block includes a source hint such as:

Mermaid flowchart (TD) · source: /copy mermaid 1

Use these commands to copy Mermaid source from the last AI response:

Command Behavior
/copy mermaid Copies the last Mermaid block.
/copy mermaid 1 Copies the first Mermaid block.
/copy code mermaid Copies the last fenced mermaid code block.
/copy code mermaid 1 Copies the first fenced mermaid code block.

/copy code 1 counts all fenced code blocks, not only Mermaid blocks. Use /copy mermaid N when you want the Mermaid-specific sequence shown in the rendered title.

LaTeX Math

Qwen Code supports basic inline and block LaTeX rendering in the terminal:

Inline math: $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

$$
\sum_{n=1}^{\infty} 1/n^2 = \pi^2/6
$$

The renderer focuses on common symbols and readable terminal output. It is not a full TeX engine; complex layouts such as matrices, aligned equations, and large nested expressions may be simplified.

Inline $...$ expressions are intentionally bounded to 1024 characters per line so malformed or very large generated Markdown cannot stall terminal rendering. Longer formulas remain visible as source text and can still be copied from raw mode or the original response.

LaTeX Source Copy

Use these commands to copy LaTeX source from the last AI response:

Command Behavior
/copy latex Copies the last block LaTeX expression.
/copy latex 2 Copies the second block expression.
/copy latex inline Copies the last inline expression.
/copy latex inline 2 Copies the second inline expression.
/copy inline-latex 2 Alias for /copy latex inline 2.

Inline LaTeX does not show a per-expression copy hint in rendered text to avoid making prose noisy. Switch to raw mode with Alt/Option+M when you want to inspect inline source in place; on macOS this requires Option-as-Meta terminal input.

General Code Copy

The /copy code command reads fenced code blocks from the last AI Markdown response:

Command Behavior
/copy code Copies the last fenced code block.
/copy code 2 Copies the second fenced code block.
/copy code typescript Copies the last typescript code block.
/copy code mermaid 1 Copies the first mermaid code block.

Selecting an Earlier AI Message

By default /copy targets the most recent AI message. Prefix the command with a positive integer to copy from the Nth-last AI message instead — handy when the latest reply is something low-signal (e.g., a TODO update) and the substantive output is one or two turns back.

Command Behavior
/copy 2 Copies the second-to-last AI message in full.
/copy 3 Copies the third-to-last AI message in full.
/copy 2 code python Copies the last python code block from the 2nd-last.
/copy 3 latex Copies the last LaTeX block from the 3rd-last message.

/copy 1 is equivalent to /copy. If N exceeds the number of AI messages in the session, /copy reports the actual count instead of copying anything. Without a leading integer, sub-selectors such as /copy code python 2 keep their existing meaning (the 2nd python block in the last message).

Current Limits

  • Mermaid image rendering depends on Mermaid CLI plus terminal image support.
  • Async iTerm2 inline image placement is disabled in the TUI because the protocol is cursor-position bound; use Kitty/Ghostty or ANSI fallback for interactive image previews.
  • Wireframe Mermaid rendering is a readable terminal preview, not a full Mermaid layout engine.
  • Raw mode is global for rendered Markdown blocks; it is not a per-block toggle.
  • LaTeX rendering covers common symbols and expressions, not full TeX layout.
  • Source copy commands target the last AI response by default, or the Nth-last when invoked as /copy N ....