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

# tandemn check

> Verify that the Tandemn CLI can reach the server.

Use `tandemn check` before submitting jobs. It confirms that your CLI configuration points at a reachable Tandemn server.

## Usage

```bash theme={null}
export TD_SERVER_URL=<your-server-url>
tandemn check
```

If the deployment requires API key authentication, set `TD_API_KEY` in the same shell session before running `tandemn check`.

```bash theme={null}
export TD_API_KEY=<your-api-key>
tandemn check
```

## When to run it

* After installing the CLI
* After changing `TD_SERVER_URL`
* After changing `TD_API_KEY`
* Before submitting a large workload
* When debugging failed job submission

## If it fails

Check:

* `TD_SERVER_URL` is set in the same terminal session.
* The server URL is correct.
* Your machine can reach the server network.
* The server is running.
* `TD_API_KEY` is set if your administrator requires it.

See [Troubleshooting](/admin/troubleshooting) for a fuller checklist.