# D69. A new module in another module's charter: the design layer copied, one screen to start (3 Nov 2026)

The app's « Nouveau module » page lets the author choose the charter of the module they create: a template's (D68), another module's of their library, or one made to measure by their AI. « Comme un autre module… » used to be a line of the request: the agent read the other module and redid its look, at the cost of a long task and a look that came out close, never the same. The question was whether copying a module's style is ambiguous enough to need an agent who judges case by case, or a command.

Decided:
- **A command.** The format already separates how a course looks from what it says (docs/design.md, the design layer): the theme in `course.json` and `theme/`, the components, the generators of its pictures, and the backdrop's decoration, a free object that carries no information (`pedagogicalRole: "decoration"`). `copyCharter` (`@elabora/node/charter`) copies that layer into a course just made; the agent is needed only for what depends on the content, which the copy leaves behind.
- **What a charter is:** `theme` whole (tokens, custom tokens, fonts, stylesheet, named styles, effects, backdrop with its layers, variants and decoration), `presentation` (its widths and fit; its mode unless the author chose one), `player` (the bars, their items and the logo), and the files these use: the stylesheet's folder, the fonts with their licences, every component, the decoration's folder, what a stylesheet's `url()`, a component or the decoration names under `assets/`, a module the decoration imports, and the generators that drew those pictures with their provenance, when what they import comes too.
- **What it is not:** the screens, the plan, the narration, the sounds, the sources, the glossary and resources, the translations, the speakers, the `ui` words, and the free objects the blocks place (a 3D lab, a canal lock: the subject). A generator that draws from one of those stays behind; its picture comes as a plain file.
- **Where it is used:** creation only. `elabora projects create --charter <project id or folder>`, `elabora_projects_create` with `charter`, and the library's `createProject` / `createModule` (the app's « Nouveau module »): a blank course (one screen, as `init` makes it) that takes the charter, with a note in its `AGENTS.md` naming the module it comes from. A module of the library is copied under its library lock, as `duplicateProject` copies it. `template` and `charter` exclude each other: a template brings its screens, a charter only the look.
- **Checked on every template and example:** a blank course in each of their charters validates without an error and `fit` passes (`test/unit/charter.test.ts`). The warnings left are a blank course's and `W_COMPONENT_UNUSED` for the components no screen uses yet, which say what is there to use. `fit` no longer reports a scroll-driven animation of a page that does not scroll as unfinished (a decoration on a first, short page).

Weighed:
- **Keep it a request to the agent.** Rejected: the format draws the line already, the copy is exact where an agent's is approximate, it takes a second instead of a task, and it works without an AI (« Créer manuellement »).
- **Duplicate the module and let the author empty it.** Rejected: its screens, plan, narration and sources would go with it, to be removed by hand; a duplicate stays the same course (its course id), which an LMS would take for it.
- **Copy only the components the charter needs (layouts, decorations).** Rejected: a component is the module's « Blocs du module »; the author who wants the same look wants its blocks, and the validator says which are not used yet.
- **Apply a charter to an existing course (a theme apply, D68's revisit).** Later: replacing a charter under screens that use the old one's components and styles needs those references mapped; creation has none.

*Revisit if:* authors want to change the charter of a module already written, or keep only some of another module's components.