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

# fly mpg attach

Attach a managed Postgres cluster to an app. This command will add a secret to the specified app
containing the connection string for the database.

## Usage

```
fly mpg attach <CLUSTER ID> [flags]
```

## Options

```
  -a, --app string             Application name
  -c, --config string          Path to application configuration file
  -d, --database string        The database to connect to
  -h, --help                   help for attach
  -u, --username string        The username to connect as
      --variable-name string   The name of the environment variable that will be added to the attached app (default "DATABASE_URL")
```

## Global Options

```
  -t, --access-token string   Fly API Access Token
      --debug                 Print additional logs and traces
      --verbose               Verbose output
```

## See Also

* [fly mpg](/flyctl/cmd/fly_mpg)	 - Manage Managed Postgres clusters.