# The book

Four chapters, in the order the work happens.

Read [the dry run][dryrun] before any of them — a complete module designed on
paper for a second game, and the shortest honest picture of the whole job.

| # | Chapter | What it covers |
| --- | --- | --- |
| 1 | [Your first module in twenty minutes](01-first-module.md) | Copy the template, rename it, build it, install it, see a page. No theory. |
| 2 | [The website module](02-website-module.md) | The bulk of the work: `module.json`, `register(ctx, api)`, the schema fragment, the client chunk, packaging, and what a module must never do. |
| 3 | [The sidecar](03-sidecar.md) | Why the website never talks to a game server, what "persist before you forward" means, and what a *thin* sidecar is. |
| 4 | [The game-side plugin](04-game-plugin.md) | The least code and the highest stakes: never block the game thread. |

Chapters 1 and 2 quote `template/`, which CI builds against a pinned core, so their
code is a tree that is proved rather than prose that looks like one. Chapters 3 and
4 cite `uo-link` and `servuo-plugins` by file and identifier rather than by line, on
purpose: those repositories move for their own reasons and a line number in a book
is wrong the moment they do.

## What is normative, and what is here

Nothing in these chapters is. Where a chapter and one of these disagree, the
document is right and the chapter has a bug — [say so][issues]:

| Authority | For |
| --- | --- |
| [`MODULE_API.md`][api] | Everything a module may do. |
| [`MODULE_SYSTEM.md`][system] | Why the module system is shaped this way, and how a module is installed and removed. |
| [`link/PLAN.md`][linkplan] + [`INTEGRATION.md`][linkint] | The game↔sidecar wire protocol, as one real sidecar implements it. |

The chapters teach: the order to do things in, the reasoning, and the mistakes that
cost this project time.

[api]: https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/website/MODULE_API.md
[system]: https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/website/MODULE_SYSTEM.md
[dryrun]: https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/modules/rust-dryrun.md
[linkplan]: https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/link/PLAN.md
[linkint]: https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/link/INTEGRATION.md
[issues]: https://gitea.whitlocktech.com/RunicGateway/Integration-kit/issues