# Environment Variables

## `LOG_LEVEL`

Set the minimum log level for the leveled methods (`debug`, `info`, `warn`, `error`).\
The plain `log()` function always prints, regardless of this value.

Valid values: `debug`, `info`, `warn`, `error`\
Default: `info`

```bash [terminal]
LOG_LEVEL=debug bun run app.ts
```

When set to `warn`, only warnings and errors are shown.

## `NODE_ENV`

When `NODE_ENV` is set to `production`, Keelog switches from colourful TTY output to **formatted JSON** suitable for log aggregators.

```bash [terminal]
NODE_ENV=production node app.js
```

Production output example:

```json [index.json]
{
  "level": "info",
  "message": "Server started",
  "data": { "port": 3000 },
  "ctx": { "file": "/app.ts", "func": "main", "line": 5 }
}
```