# !emulator

The `!emulator` Atmos YAML function retrieves live connection information (endpoint, credentials,
kubeconfig) from a running [emulator](/cli/commands/emulator/up) component, referenced by name and
resolved relative to the current stack.

## Usage

```yaml
  # Retrieve a connection value from a running emulator component.
  !emulator <component-ref> <key>
```

`<component-ref>` is the emulator component's name (resolved in the current stack). `<key>` is one of:

- `endpoint` or `url` — the emulator's base URL
- `host` — the emulator's host
- `port` — the emulator's primary bound host port
- `region` — the emulator's configured region (cloud emulators)
- `project` — the emulator's configured project (cloud emulators)
- `kubeconfig` — materializes a kubeconfig file for a Kubernetes-target emulator and returns its path
- `env.<VAR>` — a single SDK environment variable from the emulator's connection profile (for example,
  `env.AWS_ACCESS_KEY_ID`)

## Examples

```yaml
vars:
  # Point a component at a running LocalStack-style emulator instead of real AWS.
  aws_endpoint: !emulator aws-emulator endpoint

env:
  # Pass emulator credentials through to Terraform as environment variables.
  AWS_ACCESS_KEY_ID: !emulator aws-emulator env.AWS_ACCESS_KEY_ID
  AWS_SECRET_ACCESS_KEY: !emulator aws-emulator env.AWS_SECRET_ACCESS_KEY

  # Point kubectl/helm at a running k3s emulator.
  KUBECONFIG: !emulator k3s-emulator kubeconfig
```

:::info
The referenced emulator component must be running (`atmos emulator up`) before the function can resolve a value.
:::

## Related

- [`atmos emulator up`](/cli/commands/emulator/up) — start emulator components
- [`atmos emulator list`](/cli/commands/emulator/list) — list running emulators