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

# Logs

> Control stdout and stderr output routing and set LOG_LEVEL across any example

All examples route user-facing output to **stdout** and SDK internal logs to **stderr**. Control verbosity with `LOG_LEVEL` without changing code.

Source: [`examples/logs/`](https://github.com/agenticenv/agent-sdk-go/tree/main/examples/logs)

## Output routing

| Output                          | Destination |
| ------------------------------- | ----------- |
| User prompt and assistant reply | stdout      |
| SDK internal logs               | stderr      |

## Usage

From `examples/`:

```bash theme={null}
LOG_LEVEL=debug go run ./simple_agent "Hello"
go run ./simple_agent "Hello" 2>debug.log
go run ./simple_agent "Hello" 2>/dev/null   # suppress SDK logs
```

| Variable    | Default | Description                      |
| ----------- | ------- | -------------------------------- |
| `LOG_LEVEL` | `error` | `debug`, `info`, `warn`, `error` |

Optional run footers: `SHOW_LLM_USAGE=true`, `SHOW_TELEMETRY=true` — see [Running Examples](/examples/running-examples).

For OTLP log export, see [Observability](/examples/observability). For file logging in the REPL, see [CLI](/getting-started/cli).

## Learn more

<CardGroup cols={2}>
  <Card title="Logs" icon="file-lines" href="/observability/logs">
    SDK logging and OTLP export
  </Card>

  <Card title="Telemetry" icon="gauge" href="/observability/telemetry">
    Per-run telemetry footers
  </Card>
</CardGroup>