# Extracting a feature into a plugin

The runbook, written the day offscale became the first one. Follow it for music, then for the rest.

**Read first, in this order:**

1. `plugins/offscale/PLUGIN.md` — every decision and why, including the three that reversed
2. `plugins/example/` — the reference implementation, deliberately the smallest real plugin
3. `plugins/offscale/` — the worked example, all four parts
4. `src/servers/plugins/` — the system itself: `manifest`, `discover`, `mount`, `install`, `ecosystem`, `schema`, `generate`

---

## The rules. These are not preferences

**Every plugin route renders a Workspace with at least one panel.** A plugin contributes `web/panels.ts`
(`appRegistryMetas`, at least one) and `web/layout.ts` (`defaultLayout`); the shell renders
`WorkspaceView` around them. There is no way to export a component — a `web/` directory missing either
file is **refused at discovery, by name**. Non-compliance is unrepresentable, not forbidden.

**Every plugin permission is grantable, per role, at read or write.** No `kind`, no `ownerOnly`, no field
of any sort. The platform's answer is uniform; what a grant *means* — whose rows a member sees, whether a
resource is shared or per-user — is the plugin's own job, in its own queries.

**Say `permissions`, never the other word.** It already means three things in this codebase.

**The manifest holds only what a directory listing cannot say.** Identity facts and human choices:
`publisher`, `version`, `platform`, `label`, `summary`, `icon`, `color`, `permissions`. Everything
structural is convention — presence is the declaration:

```
manifest.ts        required
api/router.ts      a backend router, mounted at mountPrefix()
db/schema.ts       tables, prefixed <app-name>_
sidecar/index.ts   a process (.mjs instead means node)
web/panels.ts      panels — REQUIRED with web/
web/layout.ts      layout — REQUIRED with web/
```

`appName` is the **directory name**. The sidecar runtime is the **file extension**.

**Nothing may branch on provenance** except `mountPrefix()`. First-party and third-party differing
anywhere else means two systems, and only one gets tested.

**Uninstall never destroys data.** The generated schema barrel follows plugin **directories**, not the
install table — `db:push` drops what it cannot see, so following installs would delete a plugin's tables
on uninstall. Only deleting a plugin's source can lose its data.

---

## The order that worked

1. **Map it first.** Sidecar, api router, db, frontend, and every line of platform wiring that names it.
2. **Move the backend**: `sidecar/` → `plugins/<name>/sidecar/`, `api/<name>/router.ts` →
   `plugins/<name>/api/router.ts` (export `router`, not `<name>Router`), `officer_db/src/<name>/*` →
   `plugins/<name>/db/`.
3. **Rewrite imports.** Platform code becomes `@@/…` (resolves from `plugins/` — verified). Queries take
   `officerdb/db` and `officerdb/crypto`. Schema takes `officerdb/auth/schema` — `users.id` is the one
   reference a plugin may make.
4. **Write `manifest.ts`.**
5. **Move the frontend** to `web/`, as `panels.ts` + `layout.ts`. Imports of platform UI become
   `officerdev` (the barrel exports `WorkspaceView`, `TerminalView`, `AppRegistryMeta`); `hooks/useClient`
   and `helpers/clipboard` stay as they are.
6. **Remove every trace from the platform**, and delete rather than comment out: `hono.ts` mount and
   import, the `capabilities/registry.ts` entry, `App.tsx` routes, `Screens/Dashboard/index.tsx`,
   `AppRegistry.tsx`, `officerdev/src/index.ts` re-exports, `Dock.tsx` tile, `usePageTitle.ts` rule, and
   **both** database barrels (`index.ts` and `schema.ts`).
7. **`bunx tsgo`** until clean. It finds the wiring you missed.
8. **Verify on the live server** — see below.
9. **Commit and push.** Message says what moved, what it found, and what is still open.

---

## Verification — run all of it

```
bun test                     # 757 pass, 10 pre-existing failures. Any 11th is yours
pm2 restart officer
```

Then through `/plugins`, watching PM2 and the browser at each step:

| Step | Expect |
| --- | --- |
| install | streamed log; schema applied; sidecar online; route mounted |
| the plugin's API | answers |
| the plugin's screen | renders as a Workspace |
| dock | tile appears |
| permissions page | its permission is listed, read/write/none |
| disable | route 404s, sidecar stops, **tables and rows survive** |
| enable | comes back |
| uninstall | route gone, `pm2 list` loses it, **data still there** |
| `bun db:push` while uninstalled | `No changes detected` — data survives |
| install again | identical to the first install |

A normal refresh is enough; the shell is `no-store`. When the log's last line appears, the bundle exists.

---

## Traps, all of which cost real time once

- **Mount before starting the sidecar.** `createSidecarProxy` learns its port from a one-shot
  `<name>:server` event and subscribes when the router is first imported — at mount. Start first and the
  announcement fires into a void: online process, mounted routes, every request `503`. Already fixed in
  `install.ts`; do not reorder it.
- **`src/servers/sidecar/protocol.ts` still declares `<name>:server` per sidecar.** Music will need its
  line kept, or the union generalised to `` `${string}:server` `` — which is the better fix and is
  pending for the whole protocol.
- **`bunfig.toml` plugins do not reach `Bun.build()`.** Tailwind is passed explicitly in `generate.ts`.
- **The shell output is named for the entrypoint** (`index.gen.html`), and `naming` does not change it.
- **A stale generated file** (`Plugins.gen.tsx`, `plugin-schemas.gen.ts`) will fail the typecheck after a
  contract change. Regenerate rather than hand-edit.

---

## Music specifically — READ THIS BEFORE STARTING

**Music is bigger than offscale, and one part of it has nowhere to go.** Two others did, and the owner cut
both from tonight's scope — see below.
Mapped 2026-08-15.

**Decide these yourself. Do not stop to ask.** Every one of them has two defensible answers, the owner has
said either is fine, and a corrected decision is cheap where a stalled extraction is not. Record what you
chose and why — in the manifest, in a comment, in the commit message — and keep going. The failure mode to
avoid is not a wrong call; it is a tree left half-moved with a question attached.

### What has no home yet

1. ~~**Two websocket providers.**~~ **OUT OF SCOPE — do not touch cliamp.**

   `cliamp` and `cliamp-audio` exist for one thing: running the `cliamp` TUI player on the server and
   piping its terminal and its audio (a PulseAudio null sink tapped by `parec`) to the browser. It is a
   second, separate playback path and the owner's word is that it is the least important part of music —
   fun, wanted eventually, not tonight.

   **This is the whole reason the websocket gap does not block this extraction.** Both sockets are already
   inert (routes upgrade into commented-out handlers). Leave `sidecar/music/cliamp-ws.ts`,
   `sidecar/music/pulse-audio.ts`, `sidecar/music/asoundrc`, `src/servers/api/cliamp/relay.ts` and the two
   providers in `server.tsx` exactly where they are, untouched. If the relay's import of
   `getMusicServerWsUrl` is the only thing keeping `api/music/router.ts` alive, leave that file too and
   say so — a small documented seam is fine.

   What music actually is: the `/music` screen, the library, and the phone and tablet apps that stream
   from it. That is what has to work.

2. **A global UI overlay.** `MusicPlayerHost` is rendered by `DashboardLayout` on **every route**, not
   inside a panel, and gates itself on `can('music')`. A plugin contributes panels and a layout; there is
   no "render this everywhere" slot, and inventing one is a platform change.
3. ~~**A dashboard widget.**~~ **OUT OF SCOPE — leave it where it is.**

   `src/workspaces/widgets/MusicPlayer/` sits in a third workspace package and is wired through
   `WidgetRegistry`. Plugins cannot contribute widgets and are not going to learn how tonight. Leave the
   directory, the registration and the barrel export alone; note the seam in the manifest.

### What else differs

- **External binaries**: with cliamp out of scope, what the plugin still needs is `ffmpeg` and `ffprobe`,
  for tag reading, cover compression and poster frames. A manifest has no way to declare a host
  dependency; note it and move on. (`cliamp`, `parec`, `pulseaudio`, `pactl` and `asoundrc` stay behind
  with cliamp.)
- **Range requests**: `stream-audio.ts` does 206 / `Content-Range` / 416 and a custom `X-Audio-Duration`;
  the proxy runs at `timeoutSeconds: 1800` for reindexes. Verify `Range` survives the hop.
- **Cross-capability**: `MusicBrowser` calls `/file-browser/ls`, not the music sidecar.
- **A CLI tool**: `scripts/reindex-music.ts` reads `DATA_PATH/music/.server`.
- **Music is the platform's worked example.** `registry.ts` explains `personal` through it and
  `registry.test.ts` tests the mechanism *through the music capability*. Those tests must be rewritten
  against something else, not deleted.
- **Already half-disabled**: `hono.ts` mount and `schema.ts` export are commented out since 2026-08-13;
  `officer_db/src/index.ts:49` is still live. So the tree is mid-migration already.

### The per-user shape, which is why music was chosen

```ts
personal: ['/favorites', '/now-playing', '/playlists', '/queue'],
```

No `readOnlyWrites`. Note `/queue` — **no such route exists**, in the sidecar or the frontend. Dead or
aspirational; find out which.

Four tables, all `userId` + cascade to `users.id`: `music_favorites`, `music_playlists`,
`music_playlist_items`, `music_now_playing` (composite PK `(userId, device)`).

**And the mismatch that makes music the interesting case:** the state is per-user, the library is one
global directory. `MUSIC_ROOT = join(homedir(), 'Music')`, and `stream-audio.ts` and `cliamp-ws.ts` each
take `homedir()` as their root independently. So a granted member's favourites are theirs, while
`/stream` serves them the **owner's** files and cliamp spawns a process in the **owner's** home. The
app-store entry promises a configurable `library` folder and **nothing reads it**.

### How to decide the three, if you want a default

Each of these is "close the platform gap" or "leave the piece behind". **Closing the gap is better when
you have the runway**, because every later plugin needs it too — but a music that works with cliamp left
in the platform is worth far more than a perfect design that did not land.

| Part | Close the gap | Leave it behind |
| --- | --- | --- |
| ~~websockets~~ | — | **out of scope. Do not spend a minute on cliamp.** |
| ~~widget~~ | — | **out of scope. Leave `widgets/MusicPlayer` exactly as it is.** |
| global overlay | add one slot the shell renders from installed plugins | leave `MusicPlayerHost` in `DashboardLayout`, gated as it already is |

**One open call, then.** The player overlay is the only judgement left, and either answer is fine.

Whatever you pick, the plugin must **install, enable, disable and uninstall cleanly** at the end. A piece
left in the platform is a documented seam; a piece left dangling is a bug.

`assertCapabilityTotality` is **not** part of this. It is worth fixing eventually and the cliamp routes
are the live example of the drift it cannot see, but both are someone else's evening.

**Do not** invent music's per-user visibility model during the move. Extract with the semantics it has, or
the two changes tangle and a bug in either is a bug in both.

---

## Still open, platform-wide. Do not rediscover these

- **Websocket providers** — `server.reload({ routes })` proven, never called
- **`assertCapabilityTotality` reads the wrong list** — `Object.keys(handlers)` while Bun serves the route
  table, and plugin routes are not in `PROTECTED_API_PREFIXES` at all. It belongs in `buildHonoApp()`,
  now the single place routes are mounted. Security-adjacent; close it before members reach plugin routes.
- **Two dock sources** — the app store keeps its own catalogue; one when it is rebuilt on this
- **Offscale's queries scope by caller**, so a granted member sees their own empty list rather than the
  owner's. Its own job, not the platform's.
