# Declarative binding by module

<sub>**Intermediate.** Register where the class lives.</sub>

Prefer to declare registration where the class lives? Tag it with
`@md.scan_bind`, then register the whole module in one call.

**`services.py`** — declare intent next to the code:

```python
import melder as md


@md.scan_bind(existence="unique", permissions="create")
class MetricsHub:
    pass


@md.scan_bind(existence="many", permissions="create")
class JobTicket:
    pass
```

**`main.py`** — decide when it actually binds:

```python
import melder as md
import services

book = md.Spellbook()
bound = book.scan(services)        # ← binds every tagged class in the module
conduit = book.conjure()

hub = conduit.meld("MetricsHub")
```

The decorator **stores intent only** — nothing touches the runtime until
`scan()` runs. Importing `services` registers nothing: no hidden global
container filling up behind your back, no import-order puzzle to debug. You
still decide when binding happens, and where.

Mix freely: scan a module, then `bind()` a few more by hand.

`scan_bind` takes everything `bind()` takes for a target — `spellframe`,
`binding_name`, `resolvable`, `disposal_method_names` and your own metadata
keywords — and `permissions` is required. Only the decorated class or function
itself is registered: its subclasses and instances are not, unless they are
decorated too.


---

## Runnable examples

- [Scan bind decorator](../examples/intermediate/01-scan-bind-decorator.md) — Intermediate 01

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

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