Variables

Text that appears in many pages and changes now and then - a product name, the latest version, a support address - can be written once, in writedocs.json’s variables:

{
  "variables": {
    "productName": "Acme",
    "latestVersion": "4.2.0",
    "supportEmail": "[email protected]"
  }
}

and used in any page as [[name]]:

Welcome to [[productName]]. The latest version is [[latestVersion]] -
questions go to [[supportEmail]].

Change the value in writedocs.json, and every page that uses it changes.

Rules

• Names are made of letters, digits, _, - and ., and are case-sensitive: [[productName]] and [[productname]] are different variables.
• Values are plain text.
• A [[name]] with no variable of that name stays as written, so a typo is easy to spot on the page.
• In code, [[name]] is never replaced - both in `inline code` and in code blocks. To show a value in code, write it out.

Variables are replaced in the page’s Markdown copy, llms-full.txt and the MCP server too, so AI tools read the same text as people do.

Where they work

Variables are replaced in the page’s text, including text inside components:

<Callout type="info">[[productName]] keeps your data for 30 days.</Callout>

They aren’t replaced in a component’s props - <Card title="[[productName]]"> - or in frontmatter, like the title.