# 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//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
```