# log

Write events as structured JSON lines to stderr.  Will log at the level resolved from: `event.level` → `event.severity` → `default-level` → `info`.  This is a sink (does not emit events downstream).

## Config

**Optional:**
- `default-level` (trace | debug | info | warn | error | fatal): Default log level if not present in event (default: `info`)
- `extra` (object): Additional fields to merge into every log line (event fields take precedence)

Level resolution supports:

- Pino / Bunyan numeric: 10–60 (trace through fatal)
- Syslog numeric: 1–7 (fatal through trace)
- Named strings: `trace`, `debug`, `info`, `warn`, `warning`, `error`, `err`, `fatal`

## Example

```yaml
pipeline:
  log:
    inputs: [errors, stats]
    config:
      default-level: warn
      extra:
        env: prod
```