Markdown

Markdown

Markdown renderer used inside MessageQuestion / MessageResponse, plus syntax highlighting, tables, charts, redaction matchers, and remark/rehype plugins. Also exported standalone for custom use.

Imports

import {
  Markdown,
  CodeHighlighter,
  TableComponent,
  TableHeaderCell,
  TableDataCell,
  ChartRenderer,
  // remark plugins
  remarkCve,
  remarkComponent,
  remarkRedact,
  type RedactMatcher,
  // built-in matchers
  ssnMatcher,
  creditCardMatcher,
  bitcoinMatcher,
  commonRedactMatchers,
  // syntax themes
  dark,
  light
} from 'reachat';

Markdown

Wrapper around react-markdown that wires reachat's default component overrides for code, tables, lists, headings, links, hr, redact tags, and reads the theme from ChatContext.

Prop	Type	Default	Description
children	string	—	Markdown source
remarkPlugins	Plugin[]	—	Remark plugins (passed through)
rehypePlugins	Plugin[]	[rehypeRaw, rehypeKatex]	Rehype plugins (math + raw HTML support)
theme	ChatTheme	from context	Theme override for class names
customComponents	Components	—	Component overrides; merged on top of markdownComponents from context, which is merged on top of defaults

<Markdown
  remarkPlugins={[remarkGfm, remarkRedact(commonRedactMatchers)]}
  customComponents={{ a: CustomLink }}
>
  {markdownString}
</Markdown>

The default code renderer detects fenced blocks (language-xxx className) and routes them through CodeHighlighter; inline code falls back to a plain <code> styled by theme.messages.message.markdown.inlineCode.

A custom redact element is also wired up to render <Redact> from reablocks (used by remarkRedact).

CodeHighlighter

Standalone code-block renderer using react-syntax-highlighter (Prism build). Adds a toolbar with the language label and a copy button.

Prop	Type	Default	Description
children	string	—	Code content
language	string	—	Pass language-xxx (extracted automatically by Markdown)
theme	Record<string, string>	dark	Prism theme object (dark or light exported from reachat)
copyIcon	ReactElement	copy icon	Pass null to hide the copy button
className / inlineClassName / copyClassName / toolbarClassName	string	—	Tailwind class hooks

When language does not match language-(\w+), the component renders inline <code> only (no toolbar).

Table components

Plain wrappers used by the markdown defaults; you can re-use them in custom components:

• TableComponent — <table> with class merging
• TableHeaderCell — <th>
• TableDataCell — <td>

ChartRenderer

Renders a chart from a ChartConfig. Used internally by createChartComponentDef() and the redact-style chart fenced block. Reads theme.chart from ChatContext.

type ChartType =
  | 'bar' | 'line' | 'area' | 'pie'
  | 'radialBar' | 'radialArea' | 'sparkline';

interface ChartDataPoint { key: string; data: number | ChartDataPoint[]; }

interface ChartConfig {
  type: ChartType;
  data: ChartDataPoint[];
  width?: number;   // default 400
  height?: number;  // default 300
  title?: string;
}

<ChartRenderer
  config={{
    type: 'bar',
    title: 'Active users',
    data: [{ key: 'Mon', data: 12 }, { key: 'Tue', data: 18 }]
  }}
/>

Empty data → renders a ComponentError with a "No chart data available" warning. Non-numeric data points → an error variant.

Charts are powered by reaviz, which is an optional peer dependency — install it when using ChartRenderer or createChartComponentDef.

Remark plugins

remarkCve

Auto-links CVE identifiers in markdown to MITRE.

import { remarkCve } from 'reachat';

<Chat remarkPlugins={[remarkGfm, remarkCve]}>...</Chat>

Pattern: CVE-YYYY-NNNN (4–7 digits). Each match becomes a link to https://cve.mitre.org/cgi-bin/cvename.cgi?name=....

remarkComponent

Pass-through plugin that exists as the integration point for componentCatalog() — actual rendering happens in ComponentPre. Usually you don't import this directly; pass the components prop to Chat instead.

remarkRedact

Replaces sensitive patterns with <redact> elements that the default markdown components render via reablocks <Redact>.

interface RedactMatcher {
  name: string;
  pattern: RegExp;        // must use the global flag
  validate?: (match: string) => boolean; // skip when returns false
}

remarkRedact(matchers: RedactMatcher[]): Plugin;

import { remarkRedact, ssnMatcher, creditCardMatcher } from 'reachat';

<Chat remarkPlugins={[remarkRedact([ssnMatcher, creditCardMatcher])]}>...</Chat>

Built-in matchers exported from reachat:

• ssnMatcher — 123-45-6789
• creditCardMatcher — 13–19 digit numbers; skips obvious non-cards (years, ages, phone hints)
• bitcoinMatcher — addresses starting with 1 or 3 (26–35 chars)
• commonRedactMatchers — array containing all three above

Syntax highlighter themes

dark and light are Prism style objects re-exported for CodeHighlighter's theme prop.

Theme keys

theme.messages.message.markdown.{hr, p, a, table, th, td, code, inlineCode, toolbar, li, ul, ol, copy, h1..h6}
theme.chart.{base, title, content}
theme.chart.error.{base, title, code}
theme.chart.warning.{base, title}