# Front Matter

Any markdown file that contains a YAML front matter block will be processed by gray-matter. The front matter must be the first thing in the markdown file and must take the form of valid YAML set between triple-dashed lines. Here is a basic example:

---
title: Blogging Like a Hacker
lang: en-US
---

Between these triple-dashed lines, you can set predefined variables (see below for a reference), or even create custom ones of your own. These variables will then be available to you to access using $frontmatter at the rest of the page, plus all custom and theming components.

# Alternative Front Matter Formats

In addition, VuePress also supports JSON or TOML front matter.

JSON front matter needs to start and end in curly braces:

---
{
  "title": "Blogging Like a Hacker",
  "lang": "en-US"
}
---

TOML front matter needs to be explicitly marked as TOML:

---toml
title = "Blogging Like a Hacker"
lang = "en-US"
---

# Predefined Variables

# title

• Type: string
• Default: h1_title || siteConfig.title

Title of current page.

# lang

• Type: string
• Default: en-US

Language of current page.

# description

• Type: string
• Default: siteConfig.description

Description of current page.

# layout

• Type: string
• Default: Layout

Set the layout component of the current page.

# permalink

• Type: string
• Default: siteConfig.permalink

Refer to: Permalinks.

# metaTitle

• Type: string
• Default: `${page.title} | ${siteConfig.title}`

Override the default meta title.

# meta

• Type: array
• Default: undefined

Specify extra meta tags to be injected:

---
meta:
  - name: description
    content: hello
  - name: keywords
    content: super duper SEO
---

# Predefined Variables Powered By Default Theme

# navbar

• Type: boolean
• Default: undefined

See: Default Theme Config > Disable the Navbar.

# sidebar

• Type: boolean|'auto'
• Default: undefined

See: Default Theme Config > Sidebar.