---
title: "The Éclair 2.0 core and its 57 skills: features on demand"
description: "Why Éclair 2.0 keeps a lightweight core and hands the rest to 57 skills: benefits, foundations, what already works, limits and how to write your own skills."
url: "https://eclaircms.org/blog/eclair-2-core-skills-features-on-demand"
lang: "en"
author: "Thierry Gustin"
published: "2026-11-08"
updated: "2026-11-10"
---

# The Éclair 2.0 core and its 57 skills: features on demand

> **Key takeaways** — With version 2.0, Éclair CMS separates a lightweight, stable core from a library of 57 skills that AI assistants use to build tailor-made features. The eight foundational skills set the shared rules: architecture, storage, rights, routes, cache, security and tests. Nineteen skills are usable today, the others guide the design of shops, online schools or forums. And anyone can write their own skills for their trade.

With Éclair 2.0, the core stays small, database-free and safe from updates, and advanced features are built on demand by your AI assistant, guided by a library of **57 skills**. No more piling up plugins: each site only loads what it needs.

This article explains the change in detail: what the core is, what skills are, what they bring, what already works, what is still to be opened, and how to write your own skills.

## What is the Éclair 2.0 core?

The core is what Éclair does for every site: routing, content, security, SEO and GEO, the static cache and signed updates. 2.0 mainly adds **stable contracts**: a theme contract, which stores your design in `site/themes/`, and a feature contract, `eclair-extension/1`, which stores your site’s own code in `site/extensions/`.

Those two folders belong to your site: a core update never touches them. And a feature your site doesn’t use is not loaded. That is what keeps the core lightweight, however ambitious the project.

## What exactly is a skill?

A skill is a folder with a `SKILL.md` file and its references. Coding assistants (Claude Code, Codex and compatible agents) read it when your request matches its description. It gives them what they lack to work well on Éclair: the diagnosis to make before writing a line, the procedure, the permitted locations, the security invariants, the deliverables and the acceptance criteria.

A skill **is not a ready-to-install extension**. It is a manual for the agent. The result, a feature in `site/extensions/`, is only activated after validation, tests and review by a person.

## What are the benefits for your site?

### 🪶 Nothing useless

A shop loads the cart and VAT, not a forum. A business site only loads the core: less code, less attack surface.

### 🔄 Updates that don’t break

All your site’s own code lives outside the core. Éclair’s signed updates never overwrite it.

### 🧩 Features that combine

An academy with a shop and a forum shares the same accounts, permissions and payments, instead of three separate systems.

### 🛡️ Security by default

Rights checked on every object, payments confirmed by the server, no private data in a shared cache.

### 🧪 Proof, not promises

Each feature passes the official validator, the tests and the performance check before activation.

### 🧑‍💻 Beginner-friendly

You describe your need; the AI makes the technical choices following proven rules.

## The foundations: eight skills that set the rules

The foundations family is the most important, because every other skill builds on it. It answers the questions any developer asks before adding a feature: where to put the code, how to store data, who may do what, how to name URLs, what to cache, how to check security and how to test.

These eight skills are usable today with Éclair 2.0. And they serve as a model: anyone can use them as inspiration to write their own skills, suited to their trade.

| Skill | What it does |
| --- | --- |
| `eclair-architecture` | Decide where a feature belongs: setting, theme, extension or core RFC |
| `eclair-extension-builder` | Build a native `eclair-extension/1` extension that survives updates |
| `eclair-storage` | Choose storage, migrations and backups for data |
| `eclair-auth-roles` | Design accounts, roles and rights: members, students, customers, moderators |
| `eclair-routing` | Create public and admin routes, keep exact URLs |
| `eclair-cache-contract` | Decide what is cached, invalidated or kept dynamic |
| `eclair-security-audit` | Audit each feature before it goes live |
| `eclair-test-suite` | Write regression, security and performance tests |

## How does the AI work without breaking anything?

Skills impose a seven-gate quality path. The agent first checks the site’s version and real capabilities, stores the package in `site/extensions/`, submits it to the official validator, runs the full test suite, checks the performance budgets, runs negative security tests, then stops: **a person reviews it, activates it from the admin and tests the rollback.** If the core lacks a capability, the agent writes an RFC and a blocking test instead of inventing an API.

## What can you build today?

Nineteen skills are usable right away: the eight foundations, the seven design and user-experience skills, and four SEO, GEO and migration skills (SEO audit, GEO optimisation, WordPress migration, multilingual SEO). They let you create a theme that survives updates, custom blocks, fast public pages, admin screens and scheduled tasks, and prepare a WordPress migration without losing a URL. Two skills (product catalogue, directory) allow a public read-only prototype.

## What about the shop, the online school or the forum?

Thirty-five skills already guide the design of more ambitious projects: a full shop with cart and payment, an online school with enrolments and progress, a moderated forum, bookings, memberships, ticketing, CRM or webhook integrations. They produce specifications, data models and tests.

But they rely on building blocks the core doesn’t officially open yet: visitor sign-up and login, public writing, transactional storage, confirmed payment. Until those contracts are published, these features **must not go to production**. The good news: the design work is ready for the day they are.

## How do you create your own skills?

This is one of the big benefits of 2.0: the rules are public, so you can write a skill for your trade, a practice, a real estate agency, a sports club, and reuse it on all your sites.

1. Create a `skills/eclair-<name>/` folder with a `SKILL.md`: a name, and a description that says when to use it.
2. Write the diagnosis, the procedure, the deliverables, the security invariants and the acceptance criteria, following the foundations as a model.
3. Add your references in `references/`.
4. Declare the skill in `catalog.json` and run the library’s checks.
5. Test it on a copy of a project, then share it if you wish.

## How do you get started?

Download Éclair 2.0, get the library from [GitHub](https://github.com/Jacckisback/eclair-skills), install the foundations family, then those your project needs. The [skills guide](https://eclaircms.org/en/documentation/skills) details each step, and the [Skills page](https://eclaircms.org/en/skills) presents the 57 skills with their status.

## Frequently asked questions about the core and the skills

### Is Éclair becoming a plugin-based CMS like WordPress?

No. A WordPress plugin is generic code loaded even for the parts you don’t use. A skill guides the AI to produce only the code your site needs, isolated outside the core and tested.

### Do skills replace a developer?

Not entirely. They save a lot of time and avoid common mistakes, but a person must review, test and activate.

### Does my current site need to change?

No. A business site or a blog keeps working with the core alone. Skills are only useful if you want to add a feature.

### Are the skills free?

Yes, under the AGPL-3.0 free software license, like Éclair CMS.

[Discover the 57 skills](https://eclaircms.org/en/skills)

[Read the skills guide](https://eclaircms.org/en/documentation/skills)

— Thierry Gustin, Créateur d’Éclair CMS, consultant SEO et formateur IA · November 10, 2026