> ## Documentation Index
> Fetch the complete documentation index at: https://wundergraphinc-brendan-add-sof-link.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Debugging

> The router can be debugged and tested in multiple ways.

## Load a static execution config from file

Instead of letting the router fetch the config from the platform, you can also point to a local file. This is handy for local development. Your production config can be fetched by running [wgc router fetch](/cli/router/fetch) or [wgc router compose](/cli/router/compose) to generate a execution config without the need to interact with the controlplane.

```bash theme={null}
docker run \
    -e EXECUTION_CONFIG_FILE_PATH=/app/router.json \
    -v ./router.json:/app/router.json \
    --env-file ./.env router
```

The command above will mount your local file `config.json` into the router's working directory.

Docker `--env-file` allows you to specify all environment variables in your `.env` file instead of passing all of them through `-e` flags.

## Watch for config changes

You can enable the watch mode to perform a hot-reload of the router whenever you make changes to the configuration.

```yaml theme={null}
version: "1"

execution_config:
  file:
    path: "router.json"
    watch: true
```

## Debug log level

Enable debug mode by setting the environment variable `LOG_LEVEL=debug` or via configuration file.

```yaml config.yaml theme={null}
version: "1"

dev_mode: true
```

## Debug metrics

To inspect which OTLP metrics are being collected and exported by the router, you can enable the [Metrics Log Exporter](/router/open-telemetry#metrics-log-exporter). It prints all collected metrics to the router's log output, making it easy to verify metric names, types, attributes, and values without needing an external collector.