I built Frontmatter Core after repeatedly hitting the same problem: modern frontends and CMS don’t share the same model.

Astro components define structure through props. CMS expect explicit content models.

Frontmatter Core scans Astro, Markdown and YAML files and extracts a stable, typed JSON Intermediate Representation that adapters or CMS can consume.

It runs at build time only:

- no runtime

- no client-side JS

- no database

- no CMS coupling

The idea is to keep:

- layout in .astro

- content in .md / .yaml

- structure expressed once, in code, then exposed as data

Adapters (PHP, flat-file CMS, headless CMS, etc.) plug into the same IR.

GitHub: https://github.com/withfrontmatter/frontmatter-core

Happy to answer technical or architectural questions.