# Attach logging explicitly

Prerequisite: [configuration ownership](posture.md). Melder's root starts without
an attached raw logger. Use `md.Aether().attach_logger(logger)` to install one
after boot; passing `None` detaches it again.

The saved logging lesson uses a standard-library logger with a collecting handler.
It checks the public `aether.logger` after attachment, detachment, and
`enable_logging(logger)`, then removes and closes the demonstration's handler.

## Two enablement paths

An explicit logger passed to `enable_logging` uses the attachment path. Calling
`enable_logging()` without one instead requires the automatic logger policy and
provider setup. Do not assume creating an `AetherConfiguration` enabled that path;
follow the root-configuration lesson's activation sequence.

Own the lifetime of application logging resources explicitly. Root logger
attachment and provider configuration are separate choices; installing one sink
does not by itself describe the policy of every object already in the process.


## The workflow in code

These are the core steps from the saved example. Use its complete linked script for all class definitions and setup.

```{literalinclude} ../downloads/03_advanced/04_utility_system_logger.py
:language: python
:pyobject: main
:linenos:
```


## Runnable examples

- [Utility system logger](../examples/advanced/04-utility-system-logger.md) — Advanced 04
- [Aether config two doors](../examples/advanced/07-aether-config-two-doors.md) — Advanced 07

[All advanced examples](../examples/advanced/index.md) · [Level contents](index.md) · [Full contents](../contents.md)

[Canonical page source](https://github.com/Synaptic724/melder/blob/4b364a338debcb1c010d0f6e9dcbbabb62945ba0/docs/advanced/logging.md)