Prismantis Claude Code mod: Claude Code themes for colorful replies

Prismantis is a community mod by Nahum Litvin (NahumLitvin) that redraws Claude's replies in the transcript with color and structure, in one of 15 Claude Code themes. Markdown tables get colored headers, boxed cells and a double rule under the header, and they shrink to fit the terminal. Code blocks get a language header, a copy button and Prism highlighting for 24 languages, and shell blocks color the command word, flags, strings and comments. Code blocks tagged mermaid are drawn as colored text art: flowcharts, sequence, state, class and ER diagrams, plus bar and line charts from xychart-beta.

It also restyles the rest of the transcript. Your own prompts draw in a rounded bubble (or an accent bar or chevron). Tool calls collapse to one line such as Ran gh pr view 12 or Read ~/src/app.ts, with a status dot. The turn footer colors the duration. Slash command output gets the same markdown rendering. Numbers, versions, durations and paths take their own colors, GitHub alerts like > [!WARNING] draw as colored boxes, and Hebrew and Arabic text is laid out right to left with handling for each terminal. There are 15 themes plus mono. The README says it needs Claude Code 2.1.287 or later.

The recording asks Claude for a markdown table of the four inner planets and their moon counts, plus a one-line bash block. With prismantis loaded, the prompt is drawn in a bubble, the table is boxed with colored headers, the bash block gets its own label and a copy button, and the reply has copy, art and copy reply buttons.

Use any of the methods in the install block; they install straight from the author's own marketplace. The next reply in a session with the mod loaded is drawn by prismantis. Run /reload-plugins in sessions that were already open.

hooks/register.tsx registers render hooks on the transcript components (AssistantMessage, UserMessage, CommandOutput, ToolGroup, ToolUse and TurnDuration). Each one parses the text with the plugin's own markdown parser in hooks/markdown.ts and draws the result with hooks/render.tsx. Here is the assistant reply hook from hooks/register.tsx:

on('ui.render', { component: 'AssistantMessage' }, ($, e, next) => {
  const blocks = parseCached(e.props.text)
  if (blocks.length === 0) return next(e)
  const el = $.ui.resolve(e)
  const { Box, Text } = el
  const columns = Math.max(20, (e.viewport?.columns ?? 100) - 4)
  // ...
  return (
    <Box flexDirection="row">
      <Box width={2} flexShrink={0}>
        <Text color={style.theme.accent}>{e.props.isFirstOfReply ? '●' : ' '}</Text>
      </Box>
      <Box flexDirection="column" rowGap={1} flexGrow={1}>
        {drawMarkdown($, el, style, blocks, columns, /* ... */)}
      </Box>
    </Box>
  )
})

When there is nothing to parse, it falls back to next(e) and Claude Code draws the message itself. Parsed blocks are cached by text, so a redraw does not parse again. Mermaid blocks go through a bundled copy of beautiful-mermaid's ASCII renderer, and a diagram wider than the window stays as code. A prompt.submit hook adds the diagram hint to prompts typed at the composer or through Remote Control. The mod also adds an engine noun, $.prismantis.markdown, so other mods can draw markdown in the user's prismantis theme.

Every option is in /config under prismantis, or in pluginConfigs in ~/.claude/settings.json. The main ones:

• theme: one of the 15 palettes or mono. /prismantis theme <name> switches on the spot.
• tableStyle: box, rules, grid or minimal. headingStyle: banner, bold, underline or uppercase.
• promptStyle: bubble, bar, chevron or off. toolStyle: chat, tree-dim, tree-bold or classic. taskStyle: checks, ticks, box or progress.
• toolRows, mermaid, mermaidAscii, copyButtons, diagramHints, highlightNumbers and highlightPaths turn single features on or off.
• About 20 color slots (headingColor, tableHeaderColor, numberColor, pathColor and so on) take hex, rgb(), ansi256() or a color name.

/prismantis copy copies the last reply, and /prismantis copy code copies its last code block, without a mouse. /prismantis demo prints a showcase of every element.

We read every file the plugin loads before we ran it, including the two vendored bundles. The plugin makes no network calls, runs no commands and reads no files. Two notes are worth knowing:

• Reads your prompts applies because a prompt.submit hook attaches a short model-only note (about 190 tokens) to each prompt you type, describing what renders in this terminal. It does not change your text. Turn off diagramHints (or mermaid) to stop it.
• $.session.messages is called only by /prismantis copy, to find the last reply. $.config.set is called only by /prismantis theme, to save the theme option. $.env.get reads terminal variables such as TERM_PROGRAM and TERM to pick the right-to-left handling.

Changes the UI covers the redrawn transcript and the "Copied" toasts. Adds commands/tools covers /prismantis. hooks/vendor/prism.js and hooks/vendor/mermaid-text.js are whitespace-minified builds of Prism and beautiful-mermaid, made by the repo's scripts/build-vendor.mjs. The plugin does not run those scripts or install packages. claude plugin validate reported no warnings.

We validated it with Claude Code 2.1.291 on macOS, and claude plugin test passed all 138 of the author's tests. The author has tested it in the terminal on macOS; the desktop app and VS Code should work through the same mod API but have not been checked by hand.

• Replies look unchanged: check claude --version is 2.1.287 or later, the plugin is enabled in /plugin, and enabled is on in /config. Run /reload-plugins after installing into an open session.
• Boxes or broken lines in diagrams: turn on mermaidAscii, which draws with + - | instead of box-drawing characters.
• Copy buttons do nothing on click: your terminal may not pass clicks through. Use /prismantis copy instead.
• Colors look wrong on a light background: pick a light theme such as github-light or catppuccin-latte.