# Frontmatter

Any Markdown file that contains a YAML frontmatter block will be processed by gray-matter (opens new window). The frontmatter must be at the top of the Markdown file, and must take the form of valid YAML set between triple-dashed lines. Example:

---
title: Blogging with VuePress
lang: en-US
---

Between the triple-dashed lines, you can set predefined variables, or even create custom ones of your own. These variables can be used via the $frontmatter variable.

Here’s an example of how you could use it in your Markdown file:

---
title: Blogging with VuePress
lang: en-US
---

# {{ $frontmatter.title }}

My blog post is written in {{ $frontmatter.lang }}.

# Alternative frontmatter Formats

VuePress also supports JSON and TOML (opens new window) frontmatter syntax.

JSON frontmatter needs to start and end in curly braces:

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

TOML frontmatter 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 the current page.

# lang

Type: string
Default: en-US

Language of the current page.

# description

Type: string
Default: siteConfig.description

Description of the current page.

# layout

Type: string
Default: Layout

Set the layout component of the current page.

# permalink

Type: string
Default: siteConfig.permalink

See Permalinks for details.

# 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
---

# canonicalUrl ⓘ1.7.1+

Type: string
Default: undefined

Set the canonical URL for the current page.

# Predefined Variables Powered By Default Theme

Type: boolean
Default: undefined

See Default Theme Config > Disable the Navbar for details.

Type: boolean|'auto'
Default: undefined

See Default Theme Config > Sidebar for details.

# prev

Type: boolean|string
Default: undefined

See Default Theme Config > Prev / Next Links for details.

# next

Type: boolean|string
Default: undefined