API Reference

This page documents the public APIs exposed by ContentKit: the CLI commands, configuration schema, runtime exports, and type generation outputs.

CLI

contentkit provides three primary commands.

build

Builds your content collection(s), validates frontmatter against your schema, generates JSON data & TypeScript declaration files, and writes a virtual package dot-contentkit inside .contentkit/.

npx contentkit build

Outputs:

• .contentkit/package.json (ephemeral version with random prerelease)
• .contentkit/generated/ directory containing per‑type JSON indexes and index.js
• .contentkit/generated/index.d.ts and types.d.ts (unless generateTypes disabled)

init

Creates a starter contentkit.config.{ts|js|mjs|cjs} file in the project root if one does not already exist (or replaces a config with a different extension to match your environment).

npx contentkit init

validate

Loads and type‑checks (syntactically) the configuration file. Useful in CI to fail fast if the config is missing or malformed.

npx contentkit validate

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Configuration

Define your schema via contentkit.config.ts using defineConfig and defineCollection.

contentkit.config.ts

import { defineConfig, defineCollection, fields } from "contentkit";

const posts = defineCollection({
  name: "Post",
  directory: "./content/posts",
  include: "**/*.md",
  schema: {
    title: fields.string(),
    date: fields.date(),
    tags: fields.array(fields.string()).optional(),
  },
  computedFields: {
    slug: fields
      .string()
      .resolve((doc) => doc.title.toLowerCase().replace(/\s+/g, "-")),
  },
});

export default defineConfig({
  collections: [posts],
});

contentkit.config.js

import { defineConfig, defineCollection, fields } from "contentkit";

const posts = defineCollection({
  name: "Post",
  directory: "./content/posts",
  include: "**/*.md",
  schema: {
    title: fields.string(),
    date: fields.date(),
    tags: fields.array(fields.string()).optional(),
  },
  computedFields: {
    slug: fields
      .string()
      .resolve((doc) => doc.title.toLowerCase().replace(/\s+/g, "-")),
  },
});

export default defineConfig({
  collections: [posts],
});

defineConfig Options

Property	Type	Required	Description
collections	CollectionDefinition[]	yes	Array of collection definitions.

defineCollection Options

Property	Type	Required	Description
name	string	yes	PascalCase type name used for generated types & exports.
directory	string	yes	Base directory for the collection content.
include	string	yes	Glob pattern relative to directory selecting documents.
schema	Record<string, FieldSchema>	yes	Frontmatter schema definition.
computedFields	Record<string, ComputedField>	no	Derived fields resolved at build.

fields Helper

Use the fields helper to define your schema.

• fields.string()
• fields.number()
• fields.boolean()
• fields.date()
• fields.array(items)
• fields.list(items)
• fields.object(fields)

Chain .optional() to make a field optional.

ComputedField

Defined by chaining .resolve((doc) => ...) on a field definition.

slug: fields
  .string()
  .resolve((doc) => doc.title.toLowerCase().replace(/\s+/g, "-"));

doc will include merged frontmatter plus: _raw (metadata), raw (markdown body), html (rendered HTML).

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Build Output Structure

After contentkit build the following structure is produced:

.contentkit/
  package.json          # name: 'dot-contentkit'
  generated/
    index.js            # Imports & re-exports all type arrays + allDocuments
    index.d.ts          # (if generateTypes) ambient exports
    types.d.ts          # (if generateTypes) individual doc interfaces
    <TypeName>/
      _index.json       # Array of docs for that type

JSON Document Shape

Each JSON entry inside <TypeName>/_index.json is the hydrated document:

{
  typeName: 'Post',
  // frontmatter fields...
  // computed fields...
  raw: string;   // original markdown body
  html: string;  // rendered via marked
}

Virtual Package Import

Add a paths mapping (TypeScript) so you can import generated content:

tsconfig.json

{
  "compilerOptions": {
    "paths": {
      "dot-contentkit": [".contentkit/generated"],
    },
  },
}

jsconfig.json

{
  "compilerOptions": {
    "paths": {
      "dot-contentkit": [".contentkit/generated"],
    },
  },
}

Then:

TypeScript

import { allPosts } from "dot-contentkit";
console.log(allPosts[0].title);

JavaScript

import { allPosts } from "dot-contentkit";
console.log(allPosts[0].title);
// CommonJS: const { allPosts } = require('dot-contentkit');

• DocumentTypeNames string literal union of names
• DataExports shape of the generated exports

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Frontmatter Parsing

Supported frontmatter formats:

• YAML (default between --- delimiters)
• JSON (object literal between --- if it starts/ends with {})
• TOML (between +++ delimiters)

Validation errors display a colored table; the build exits with code 1 if a required or typed field is invalid.

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Error Codes

Some known error codes surfaced via the logger:

Code	ID	Description
E001	CONFIG_NOT_FOUND	No config file located.
E002	INVALID_FRONTMATTER_FORMAT	Unsupported or malformed frontmatter.
E003	INVALID_FRONTMATTER_FORMAT_NO_DELIMITER	Missing frontmatter delimiters.

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Example End-to-End

npx contentkit init
# edit contentkit.config.ts to add documentTypes
mkdir -p content/posts
printf "---\ntitle: Hello\ndate: 2025-01-01\n---\n\nBody." > content/posts/hello.md
npx contentkit build

import { allPosts } from "dot-contentkit";
console.log(allPosts[0].title);

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Versioning Note

The internal package version uses a random prerelease per build (e.g. 0.0.0-1A2B3C4D). Treat .contentkit as transient build output—do not publish or commit unless you need deterministic deploy artifacts.

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FAQ

• Q: How do I add new fields?
  A: Add them to the fields object of a DocumentTypeDefinition; re-run build. Missing required fields or wrong types fail the build.
• Q: Can I disable type generation?
  A: Set generateTypes: false in the config.
• Q: How do I change CommonJS vs ESM?
  A: Set outputFormat: 'cjs' | 'esm'. ESM uses JSON import assertions.

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If something is missing here, please open an issue or PR on GitHub.