# 02 · Explore the anatomy

Before changing anything, understand the four pieces that make the app work: the manifest, the generated plugin map, the registry for custom code, and AGENTS.md. After this step you'll know where to reach for each kind of change.

## `app.manifest.json` — the center of everything

This is the file that describes the whole app. Freshly created, an admin app looks like this:

```json
{
  "manifestVersion": 2,
  "id": "my-store",
  "name": "my-store",
  "backend": { "provider": "mock" },
  "locale": {
    "default": "pt-BR",
    "supported": ["pt-BR", "en"],
    "currency": "BRL"
  },
  "theme": { "brand": "violet" },
  "surfaces": {
    "admin": {
      "scaffold": "admin",
      "plugins": [{ "id": "dashboard" }],
      "pages": []
    }
  }
}
```

Three blocks matter more than the rest:

- **`surfaces`** — each surface is one face of the app (`admin`, `storefront`, `member`). It declares a `scaffold` (the shell layout), the list of `plugins` and extra `pages`. Navigation is derived from the plugins: you turn a plugin on and its routes and menu appear — you don't write routes by hand.
- **`plugins`** — inside a surface, each entry is just `{ "id": "..." }`. That's how you add a capability (step 04).
- **`backend`** — `{ "provider": "mock" }` runs on sample data with zero configuration. In step 05 you switch it to `"supabase"`.

## `src/plugins.generated.ts` — the plugin map

```ts
// Generated by 'fayz create'. Maps manifest plugin ids → platform-bundled plugin factories.
export {}
```

This file connects the manifest's `id`s to the real plugin factories. Today it comes empty because catalog plugins are resolved by the platform bundle. Treat it as generated: you don't edit it by hand — the manifest is the source of truth.

## `src/registry.tsx` — your code

```tsx
//   import { registerBlock } from './lib/fayz-runtime'
//   registerBlock('custom:my-block', MyBlock)
export {}
```

This is where you register your own blocks, pages and components (levels 5–7 of the customization ladder) and then reference them from the manifest by their `custom:` id. While you're only configuring, it stays empty.

## `AGENTS.md` — the manual for an agent

The scaffold includes an `AGENTS.md` describing the structure, the customization checklist and the Supabase walkthrough. The idea is concrete: you can open this app with an AI agent and it already knows that "customizing = editing the manifest, not writing new code", where the files live and how to connect a real database. It's documentation for the machine, versioned alongside the app.

See also: [Connect your agent](/en/docs/ai/connect-your-agent) — how to point Claude Code, Cursor or Codex at `AGENTS.md` and `llms.txt`.

{% callout type="tip" %}
✓ You should see: opening `app.manifest.json`, the `surfaces.admin.plugins` block with a single `{ "id": "dashboard" }`. Remember where that is — the next steps edit exactly it.
{% /callout %}

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