# Notifications

Notifications send messages to people. Pair them with an [`@on` consumer](<https://sandloom.dev/docs/modules/between/events/index.md>) to notify when something happens.

## What a module calls

```
from sandloom.sdk.infra import Notification, notifier

await notifier().send(
    Notification(channel="email", recipient=..., subject=..., body=...)
)
```

A module that cannot work without email states it, and startup checks it: `CapabilityRequirement("notification", features=frozenset({"email"}))`.

Choose the driver with `NOTIFIER_BACKEND`.

## Drivers

### `log`

The default. It only records that a message was sent, never the raw recipient or the body.

**Limits.** Logging is not delivery: in production it advertises no channel, so a module requiring `email` fails at startup unless `SANDLOOM_ACCEPTED_RISKS` lists `log_notifier_in_prod`.

### `smtp`

Sends email through an SMTP server. Set `NOTIFIER_BACKEND=smtp` and the `SMTP_*` settings, from the [configuration reference](<https://sandloom.dev/docs/reference/configuration/#notifications>). It supports the channel `email`.

To send through another service, [write a driver](<https://sandloom.dev/docs/infrastructure/write-a-driver/index.md>).