A CMS engineered for the modern web

Content under control. Code without compromise.

FlatFile CMS combines the simplicity of YAML files with a secure admin panel, server-side rendering and a ready-to-use API — without a heavy database.

Explore features See the architecture

0: required external services
<50 ms: typical response time
100%: content stored in your repository

content.yml

1schemaVersion: 1

2layout: default

3blocks:

4 - type: tech-hero

5 enabled: true

6 data:

7 runtime: PHP 8.5+

VALIDATEDSSR · API · YAML

Built on proven foundations

PHP8.5+ / strict types
YAMLhuman-readable
SQLiteauth & runtime
CommonMarksafe markdown
REST API/api/v1

One engine, many possibilities

Everything a modern CMS needs.

From content modelling to secure publishing. Every layer is designed as a clear, testable module.

Blocks without limits

Define fields in YAML, add a PHP renderer and optional assets. The CMS discovers the component automatically.

Hybrid rendering

The same validated content powers fast server-rendered HTML and the public REST API.

Secure filesystem

Atomic writes, controlled paths and symlink rejection protect content at every stage.

Multilingual by design

Localized URLs, translated fields and intelligent default-language fallback are part of the contract.

Web-ready media

MIME validation, SVG sanitization, image variants and fingerprinted URLs work automatically.

Administration and audit

User roles, passkeys, CSRF protection, rate limits and audit logs provide control without sacrificing simplicity.

Transparent architecture

From file to finished page.

Content follows one consistent path. The API and HTML use the same model, keeping every output aligned.

✓One source of truth. No hidden synchronization.

01
Content in YAMLHuman-readable and Git-friendly
02
Content repositorySecure reads and stable page identities
03
Block validationTypes, rules and content localization
04
Shared ViewModelSEO, navigation, media and content in one place
05
HTML or JSONSSR for visitors, API for integrations

blocks/feature-grid/block.yml

schemaVersion: 1
name:
  pl: Siatka możliwości
icon: grid-2
fields:
  title:
    type: text
    required: true
    translatable: true
  items:
    type: repeater
    minItems: 3
    fields:
      title:
        type: text
        translatable: true

Developer experience

A new block in three simple files.

The schema drives the admin UI and validation, the renderer owns semantic HTML, and fingerprinted CSS is published automatically only when the block is present.

✓Automatic forms in the administration panel
✓Validation and localization without controller code
✓CSS and JavaScript loaded only on pages that use them

Flat-file, full power

Let’s build a better content layer.

A lightweight core, predictable contracts and complete control over the code. FlatFile CMS is ready for its first real project.

Open the CMS panel