station-master-startos/README.md

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  <img src="icon.png" alt="Station Master Logo" width="21%">
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# Station Master on StartOS

> Everything not listed in this document should behave the same as upstream
> Station Master. If a feature, setting, or behavior is not mentioned here,
> the upstream documentation is accurate and fully applicable — see the
> Documentation section of `instructions.md` for links.

Station Master is a railroad operations board game with an authoritative multiplayer server;
solitaire needs no server and is not what this package is for. This package runs that server —
the browser client, the lobby, and the intent/SSE API — as a single StartOS service.

---

## Table of Contents

- [Image and Container Runtime](#image-and-container-runtime)
- [Volume and Data Layout](#volume-and-data-layout)
- [File Models](#file-models)
- [Dependencies](#dependencies)
- [Network Access and Interfaces](#network-access-and-interfaces)
- [Installation and First-Run Flow](#installation-and-first-run-flow)
- [Actions](#actions)
- [Tasks](#tasks)
- [Health Checks](#health-checks)
- [Backups and Restore](#backups-and-restore)
- [Limitations and Differences](#limitations-and-differences)
- [Quick Reference for AI Consumers](#quick-reference-for-ai-consumers)

---

## Image and Container Runtime

Built from source with a custom `Dockerfile` — there is no published Station Master image.

| What to Document | Value |
| --- | --- |
| Image source | Custom multi-stage `Dockerfile`: `node:*-slim` builder runs `npm run build:web` to produce the static client, then a second `node:*-slim` stage copies only `package.json`, `src/`, and the built `dist/` — no `node_modules` in the runtime stage, since the server has zero runtime dependencies |
| Architectures | x86_64, aarch64 |
| Entrypoint | `node src/server/index.ts` — runs straight from TypeScript source; no compile step, see Limitations |

One subcontainer: `station-master-sub`, running the single daemon `server`.

## Volume and Data Layout

One volume, `data`, mounted at `/data` (`DATA_DIR`).

| What to Document | Value |
| --- | --- |
| Volume names | `data` |
| Mount points | `/data` |
| StartOS files | `store.json` — holds the join secret (see File Models) |
| Database | None — flat files. Each game is `games/<gameId>/game.json` (`{ engineVersion, seed, config, playerNames, history, status, createdAt }`) plus `turn-timings.json`, an `index.json` naming every game, and lobby state for games not yet started |

## File Models

One StartOS-managed file, `store.json`, on the `data` volume.

- **`store.json`** — JSON, holds `joinSecret` (a string). Seeded on install with a random
  24-character value (`init/generateJoinSecret.ts`) — the daemon will not start without one, so
  it is never left unset. Rewritten only by the **Get Join Secret** action, which generates a new
  value on every run; the value is otherwise never touched, so a hand edit to it survives until
  the action is next run. `main.ts` reads it reactively, so a rewrite restarts the daemon with the
  new value automatically.

Everything else under `/data` — `games/`, `index.json`, lobby and session state — is the
application's own persistence, written directly by the server process, not by a StartOS file
model.

## Dependencies

None.

## Network Access and Interfaces

One interface, `ui`, on the single port the daemon listens on. It serves the browser client, the
lobby and intent HTTP API, and the per-seat SSE game stream — all from the same origin, which is
what lets a player reach the server from a LAN address and another player reach it from a
different one in the same game.

## Installation and First-Run Flow

No setup wizard. On install, a join secret is generated and stored immediately (see File Models),
and a critical task is raised pointing at **Get Join Secret** — the service starts and is usable
the moment the daemon is healthy, but a player cannot create or join a game until the join secret
has been retrieved and shared with them.

## Actions

- **Get Join Secret** (`get-join-secret`) — run this any time you want to read the current join
  secret, or to invalidate it and issue a new one. Every run **generates a fresh secret,
  overwrites the stored one, and restarts the daemon** with it — there is no read-only mode.
  Rotating does not disconnect players already seated in a running game (D14's join secret gates
  the lobby door, not an in-progress session); it only invalidates the old value for anyone who
  has not yet joined or created a game. Completes in a few seconds, safe to repeat.

## Tasks

- **Get the join secret to share with players** — raised on install, severity `critical`. Points
  at the **Get Join Secret** action. Clears the moment that action is run for the first time; it
  does not return afterward (running it again to rotate does not re-raise it).

## Health Checks

- **Multiplayer Server** — `checkPortListening` against the daemon's port. "Not ready" means the
  process has not yet bound its port; on a normal start this clears within a second or two; on a
  cold container start it briefly reflects the daemon starting up.

## Backups and Restore

Strategy: the entire `data` volume is backed up wholesale (`ofVolumes`) — every file copied
exactly as it sits on disk, nothing dumped and replayed.

That includes every game's full intent history, so a restore can resume any in-progress game
exactly where it left off, and the join secret in `store.json`, so previously shared join links
keep working after a restore. Nothing needs to be rebuilt or re-entered after a restore; the
server resumes every saved game on boot the same way it does after an ordinary restart.

## Limitations and Differences

1. **No compile step.** The image runs the server directly from TypeScript source using Node's
   native type stripping, rather than building a `dist/` for the server the way the browser
   client is built. This is upstream's own deployment shape (`docs/architecture/deployment.md` in
   the game repo), not something this package changed.
2. **The join secret has no per-player identity.** It is a single server-wide value (D14) that
   gates who may create or join a game — it is not a username or password, and StartOS has no
   visibility into who a player is once they've joined.
3. **No accounts, and one game at a time per person is expected but not enforced** — a deliberate
   upstream design decision (`docs/architecture/multiplayer.md` §11 D13), not a StartOS-specific
   limitation.

---

## Quick Reference for AI Consumers

```yaml
package_id: station-master
image: built from source (Dockerfile)
architectures: [x86_64, aarch64]
subcontainers: [station-master-sub]
volumes:
  data: /data
file_models:
  - store.json
startos_managed_env_vars:
  - DATA_DIR
  - JOIN_SECRET
dependencies: none
interfaces:
  ui: { type: ui, port: 8081 }
actions:
  - get-join-secret
tasks:
  - { action: get-join-secret, severity: critical }
health_checks:
  - Multiplayer Server
```