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+# Nuclear Option Dedicated Server Docker
+
+A Docker setup for running a [Nuclear Option](https://store.steampowered.com/app/2376900/Nuclear_Option/) dedicated server.
+
+## Prerequisites
+
+- Docker and Docker Compose
+- A Steam account that owns Nuclear Option (or use anonymous login if the app supports it)
+
+## Quick Start
+
+1. Clone this repository.
+
+2. Create a `.env` file with your Steam credentials:
+
+   ```env
+   STEAM_USERNAME=your_username
+   STEAM_PASSWORD=your_password
+   ```
+
+   Or use anonymous login:
+
+   ```env
+   STEAM_USERNAME=anonymous
+   ```
+
+3. Start the server:
+
+   ```sh
+   docker compose up -d
+   ```
+
+The entrypoint will download/update the server files via SteamCMD, apply any overlay files, and launch the server.
+
+## Configuration
+
+### Server Config via Environment Variables
+
+You can override fields in `DedicatedServerConfig.json` by setting environment variables prefixed with `CONFIG_` in your `.env` file. The field name is uppercased.
+
+| Environment Variable      | Type    | Description                                    |
+| ------------------------- | ------- | ---------------------------------------------- |
+| `CONFIG_MISSIONDIRECTORY` | string  | Path to the missions directory                 |
+| `CONFIG_MODDEDSERVER`     | boolean | Whether the server is modded (`true`/`false`)  |
+| `CONFIG_HIDDEN`           | boolean | Hide the server from the browser               |
+| `CONFIG_SERVERNAME`       | string  | Server name shown in the server browser        |
+| `CONFIG_PASSWORD`         | string  | Server password (empty for no password)        |
+| `CONFIG_MAXPLAYERS`       | number  | Maximum number of players                      |
+| `CONFIG_DISABLEERRORKICK` | boolean | Disable kicking players on error               |
+| `CONFIG_NOPLAYERSTOPTIME` | number  | Seconds before stopping when no players are on |
+| `CONFIG_POSTMISSIONDELAY` | number  | Delay in seconds after a mission ends          |
+| `CONFIG_ROTATIONTYPE`     | number  | Mission rotation type                          |
+
+### Direct Config Editing
+
+You can also edit `nuclearoption/DedicatedServerConfig.json` directly. This file is mounted into the container at `/app`.
+
+### Overlay
+
+Any files placed in an `overlay/` directory will be copied over the server installation at `/app` on each startup. This is useful for adding custom missions, mods, or overriding specific files.
+
+## Volumes
+
+| Host Path         | Container Path | Purpose                       |
+| ----------------- | -------------- | ----------------------------- |
+| `./nuclearoption` | `/app`         | Server installation directory |
+| `./overlay`       | `/overlay`     | Optional file overlay         |
+
+## Networking
+
+The container uses `network_mode: host`, so the server binds directly to the host's network interfaces. No port mapping is needed.
+
+## Logs
+
+Server logs are written to `nuclearoption/logs/`.