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

# Deployment

A Copper application deploys as a single binary, with templates, static assets, and migrations embedded at build time.

### Building

To compile your application for production, run the `build` command:

```
copper build
```

This regenerates wire code, embeds your frontend's built assets, and compiles every target under `cmd/` into `build/`:

```
build/app.out
build/migrate.out
```

If your application has a `web/` frontend, you should run its production build first, since `copper build` embeds the build output but does not run the frontend build itself:

```
cd web && bun run build
```

You may use the `--only` flag to build specific targets:

```
copper build --only=app,migrate
```

### Running in Production

Run migrations first, then start the app with your production config:

```
./build/migrate.out -config config/prod.toml
./build/app.out -config config/prod.toml
```

Copper shuts down gracefully on `SIGINT` and `SIGTERM`: in-flight requests finish, background goroutines are waited on, and cleanup hooks run, all within a 30-second limit. You should point your process manager's stop signal at `SIGTERM` and allow at least that long.

### Production Configuration

You should keep `config/prod.toml` free of secrets. Since config files are templates, you may pull secrets from the environment or a secrets manager at startup:

```toml config/prod.toml theme={null}
extends = ["base.toml"]

[csql]
dsn = "{{ .EnvVars.DATABASE_URL }}"

[rockets]
telemetry_api_key = "{{ exec "gcloud secrets versions access latest --secret=TELEMETRY_API_KEY" }}"

[clogger]
format = "json"
level_filter = ["info", "warn", "error"]
```

JSON logs with a level filter play well with log aggregators. To learn more, see [Configuration](/the-basics/configuration) and [Logging](/the-basics/logging).

### Docker

Copper apps containerize well, since the whole application is a single binary plus a config directory. To learn how to write a multi-stage Dockerfile with proper layer caching, see [Docker](/digging-deeper/docker).

### One-Off Overrides

You may override any config value at the command line without editing files:

```
./build/app.out -config config/prod.toml -set "chttp.port=8080"
```