> ## Documentation Index
> Fetch the complete documentation index at: https://openturn.io/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Run a local hosted stack

> Use `openturn dev` to run your game with an authoritative Bun server, SQLite persistence, and anonymous auth.

Before you deploy to openturn cloud, you want to prove the multiplayer flow on your own machine. `openturn dev` runs a production-shaped hosted stack against your project's `app/` folder. No cloud credentials, no network configuration.

## Prerequisites

You need a project with the three-file layout:

* `app/game.ts` exporting `game` and `match`.
* `app/page.tsx` rendering the React UI.
* `app/openturn.ts` with metadata. For hosted, set `runtime: "multiplayer"`.

See [tutorial: tic-tac-toe multiplayer](/docs/tutorials/tic-tac-toe-multiplayer) for the layout.

## Start the server

From the project root:

```bash theme={null}
openturn dev app
```

Or with options:

```bash theme={null}
openturn dev app --port 4010 --db .openturn/dev.sqlite
```

The CLI starts a Bun HTTP server that:

* Serves the bundled React app at `/play/<deploymentID>`.
* Hosts a WebSocket endpoint for `@openturn/client` to connect to.
* Runs your authored game inside `@openturn/server`'s `createRoomRuntime`.
* Persists rooms in a SQLite database (default `.openturn/local-dev.sqlite`).
* Signs anonymous session tokens with `@better-auth` so each window gets its own user.

## Play

Open the play URL in two browser windows. In the first window, create a room. Share the invite URL (the CLI also prints it on room creation) to the second window. Both windows land in the same lobby.

When the lobby reaches its minimum player count, `LobbyRuntime` signs game tokens and the clients transition into the hosted match. Moves dispatched in either window go over WebSocket to the shared runtime and broadcast back as `BatchApplied` messages.

## Inspect what is happening

The CLI logs every room action, token issuance, and WebSocket event. Open the SQLite database with any SQLite client to see the persisted room records:

* `openturn_rooms` — current room state (checkpoint, log, match).
* `openturn_room_players` — seat assignments.
* `openturn_audit_events` — room audit log.

Because rooms are persisted, you can stop the server and resume; clients reconnecting pick up from the last revision.

## Hot reload

`openturn dev` watches `app/game.ts`. Saving a change rebuilds the bundle and swaps the deployment in-process. Open rooms keep running against the previous deployment version; new rooms pick up the update.

For serious game-logic iterations, reset by deleting the SQLite file between runs or passing a fresh `--db` path.

## Resetting a dev database

```bash theme={null}
rm .openturn/local-dev.sqlite
openturn dev app
```

A new schema is created on boot.

## Using the runtime programmatically

If you need a custom dev shell, the CLI server is also exported:

```ts theme={null}
import { startLocalDevServer } from "@openturn/cli";
import { loadGameDeployment } from "@openturn/server";

const deployment = loadGameDeployment(await import("./my-deployment.ts"));
const server = await startLocalDevServer({ deployment, port: 4010 });
```

You will rarely need this; `openturn dev` covers the common case.

## Related

* [Tutorial: tic-tac-toe multiplayer](/docs/tutorials/tic-tac-toe-multiplayer) walks through the full local hosted flow.
* [How-to: deploy to openturn cloud](/docs/how-to/deploy-to-openturn-cloud) for the production path.
* [Reference: cli](/docs/reference/cli) and [reference: server](/docs/reference/server).