> ## Documentation Index
> Fetch the complete documentation index at: https://terminal49-wayfair-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Alert on LFD Changes and Container Availability

> Use webhooks to monitor Last Free Day changes and container availability so you can dispatch pickups before demurrage charges begin.

Last Free Day (LFD) is the deadline to pick up a container before demurrage charges start. Terminals and shipping lines can change the LFD at any time. Terminal49 sends webhook events whenever the LFD changes or a container becomes available for pickup so you can act before costs accrue.

## Events to subscribe to

| Event                               | When it fires                                                            |
| ----------------------------------- | ------------------------------------------------------------------------ |
| `container.pickup_lfd.changed`      | The terminal's Last Free Day changed                                     |
| `container.pickup_lfd_line.changed` | The shipping line's Last Free Day changed                                |
| `container.transport.available`     | The container is available for pickup at the destination                 |
| `container.updated`                 | Container attributes changed (may include holds or availability updates) |

## Handle LFD change events

When a `container.pickup_lfd.changed` event fires, the `included` array contains the full container object with the updated `pickup_lfd` field:

```javascript theme={null}
app.post("/webhooks/terminal49", (req, res) => {
  const { data, included } = req.body;
  const event = data.attributes.event;

  if (event === "container.pickup_lfd.changed") {
    const container = included.find((obj) => obj.type === "container");
    const shipment = included.find((obj) => obj.type === "shipment");

    const containerNumber = container.attributes.number;
    const newLfd = container.attributes.pickup_lfd;
    const bolNumber = shipment.attributes.bill_of_lading_number;

    const daysUntilLfd = Math.ceil(
      (new Date(newLfd) - new Date()) / (1000 * 60 * 60 * 24)
    );

    if (daysUntilLfd <= 2) {
      await alertDispatch({
        priority: "urgent",
        message: `Container ${containerNumber} (${bolNumber}) — LFD is ${newLfd}, ${daysUntilLfd} days away`,
      });
    }
  }

  res.sendStatus(200);
});
```

## Determine pickup readiness

A container is ready for pickup when `available_for_pickup` is `true` **and** there are no active holds. Combine the `container.transport.available` event with hold checking:

```javascript theme={null}
function isReadyForPickup(container) {
  const { available_for_pickup, holds_at_pod_terminal } = container.attributes;
  const hasActiveHolds = holds_at_pod_terminal?.some(
    (h) => h.status === "hold"
  );
  return available_for_pickup === true && !hasActiveHolds;
}
```

For a deeper explanation of holds, fees, and the `available_for_pickup` field, see [Container Holds, Fees, and Release Readiness](/api-docs/in-depth-guides/holds-and-fees).

<Tip>
  Subscribe to both `container.transport.available` and `container.updated` events. The `available` event fires when the terminal first marks the container as released, but subsequent hold changes arrive as `container.updated` events.
</Tip>

## Common patterns

* **Demurrage prevention** — alert when LFD is within 48 hours and the container has not been dispatched
* **Automated dispatch** — trigger a drayage order as soon as the container clears holds
* **LFD comparison** — track both terminal and shipping line LFDs; the earlier date is the one that matters
* **Hold monitoring** — watch for `container.updated` events where `holds_at_pod_terminal` changes

## Related

* [Container Holds, Fees, and Release Readiness](/api-docs/in-depth-guides/holds-and-fees) — full guide to hold and fee fields
* [Event catalog](/api-docs/webhooks/event-catalog) — all available events
* [Payload examples](/api-docs/useful-info/webhook-events-examples) — complete JSON payloads