Frontmatter

Every frontmatter field a page accepts, all optional — title, description, sidebar, SEO, search, and the rest, with what each one controls.

Every page accepts the following frontmatter. All fields are optional.

PropType

title?string

Page title.

Typestring

description?string

Page summary.

Typestring

type?string

Content type. blog/changelog drive feeds.

Typestring

Defaultdoc

date?string

Publish date for blog/changelog feeds (ISO or YAML date).

Typestring

authors?string | string[] | object[]

Post author(s) for blog/changelog content — a name, or objects with a name plus optional avatar/url and any extra fields. Preserved as-is.

Typestring | string[] | object[]

slug?string

Override the generated slug.

Typestring

draft?boolean

Exclude from production builds.

Typeboolean

Defaultfalse

lastModified?string

Pin the page's "last updated" date (ISO or YAML date); overrides the git-derived date.

Typestring

sidebar:
  label: Install
  order: 2
  icon: download
  badge: New
  hidden: false

SEO

seo:
  title: Install Blume
  description: Install Blume and scaffold your first project.
  image: /og/install.png
  canonical: https://acme.com/install
  noindex: false

Search

search:
  exclude: false
  tags: [api]

Changelog

Changelog entries (type: changelog) accept an optional changelog object for richer feed and display metadata:

type: changelog
changelog:
  version: 1.2.0
  date: 2026-06-20
  category: Features

date may live here or at the top level — both feed the changelog RSS feed. See Changelog for the generated timeline page and feed.

Any key outside this reference fails the build, so typos are caught early. Projects that carry their own metadata can opt extra keys in via frontmatter.extend in blume.config.ts, each validated by a schema the project supplies:

import { defineConfig } from "blume";
import { z } from "zod";

export default defineConfig({
  frontmatter: {
    extend: {
      owner: z.string(),
      reviewedAt: z.coerce.date().optional(),
    },
  },
});

---
title: Install
owner: "@sam"
reviewedAt: 2026-06-20
---

Schemas are accepted through the Standard Schema interface, so Zod (whichever version your project installs), Valibot, and ArkType all work. Every declared key is validated on every page — absent ones included — so a required schema enforces the key site-wide; mark it .optional() to validate only where present. All other keys stay strictly validated, and built-in fields can’t be redeclared.

A page that fails validation fails blume build with a diagnostic naming the file and key. With --no-strict, the build succeeds anyway and the failing pages are dropped from the output — the build summary reports how many.

Schemas are exported from blume/schema for editor and migration tooling.

Frontmatter

Sidebar

SEO

Search

Changelog

Custom keys