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

# Realtime

> How to receive real-time events with the Python SDK over WebSocket

Use `client.events` with `AsyncVZapsClient` to receive instance events in real time without exposing a public URL.

For HTTP callbacks, see [Webhooks](/en/sdk/python/webhooks).

## Common events

| Event                     | Description                            |
| ------------------------- | -------------------------------------- |
| `Message`                 | New incoming message or message event. |
| `ReadReceipt`             | Read/delivery update.                  |
| `Presence`                | User presence.                         |
| `ChatPresence`            | Chat presence.                         |
| `HistorySync`             | History synchronization.               |
| `Connected`               | Instance connected to WhatsApp.        |
| `Disconnected`            | Instance disconnected.                 |
| `GroupParticipantsAdd`    | Participants added to group.           |
| `GroupParticipantsRemove` | Participants removed from group.       |
| `All`                     | All subscribed events.                 |

## Subscribe to realtime

```python theme={null}
import asyncio

from vzaps import AsyncVZapsClient

async def main():
    async with AsyncVZapsClient(
        client_token="your-client-token",
        client_secret="your-client-secret",
    ) as client:
        async with client.events.subscribe(
            instance_id="VZ...",
            instance_token="instance-token",
            events=["Message", "ReadReceipt", "Connected", "Disconnected"],
            reconnect=True,
            max_retries=10,
            retry_delay_seconds=1.0,
        ) as subscription:
            await subscription.wait_closed()

asyncio.run(main())
```

**Return:** `EventSubscription` — object with `on()`, `close()`, and automatic reconnect when configured.

Options:

| Field                 | Type        | Required | Description                                                     |
| --------------------- | ----------- | -------- | --------------------------------------------------------------- |
| `instance_id`         | `string`    | Yes      | Instance to watch.                                              |
| `instance_token`      | `string`    | Yes      | Instance token.                                                 |
| `events`              | `list[str]` | No       | Event list. If omitted, uses events subscribed on the instance. |
| `reconnect`           | `boolean`   | No       | Reconnect automatically. Default: `True`.                       |
| `max_retries`         | `number`    | No       | Maximum retry attempts.                                         |
| `retry_delay_seconds` | `number`    | No       | Base delay between retries.                                     |
| `last_event_id`       | `string`    | No       | Resume cursor.                                                  |

## Register handlers

```python theme={null}
@subscription.on_open
async def on_open():
    print("Realtime connected")

@subscription.on("Message")
async def on_message(event):
    print(event.id)
    print(event.instance_id)
    print(event.data)

@subscription.on("All")
async def on_all(event):
    print("Received event:", event.type)

@subscription.on_error
async def on_error(error):
    print("Realtime error:", error)
```

## Close subscription

```python theme={null}
await subscription.close()
```

**Return:** `Promise<void>` after the WebSocket closes.

In long-running processes, close on shutdown:

```python theme={null}
import signal

def shutdown():
  asyncio.create_task(subscription.close())

signal.signal(signal.SIGINT, lambda *_: shutdown())
```

## Event envelope

Every event received by the SDK has this shape:

```json theme={null}
{
  "id": "evt_01J...",
  "type": "Message",
  "instance_id": "VZ...",
  "created_at": "2026-06-23T22:57:17.000Z",
  "data": {
    "type": "Message",
    "media_url": "https://cdn.example.com/media/image.jpg"
  }
}
```

Fields:

| Field            | Description                                                                          |
| ---------------- | ------------------------------------------------------------------------------------ |
| `id`             | Event identifier. Use for deduplication.                                             |
| `type`           | Event type.                                                                          |
| `instance_id`    | Source instance.                                                                     |
| `created_at`     | Event creation date.                                                                 |
| `data`           | Event payload.                                                                       |
| `data.media_url` | Media URL when the incoming event contains media and the platform provides the file. |

## Delivery and ack

Delivery is **at-least-once**. Your app should process events idempotently.

After the handler finishes, the SDK automatically sends an ack.

Recommendations:

* store `event.id` if your automation performs external effects;
* ignore events that were already processed;
* use `last_event_id` when reconnecting if you want to reduce gaps;
* keep handlers fast and move long-running work to your own queue.

## Realtime or webhook?

| Scenario                                          | Recommendation |
| ------------------------------------------------- | -------------- |
| Bot, dashboard, or app with immediate consumption | Realtime       |
| Backend with public URL and HTTP pipeline         | Webhook        |
| Do not want to expose a public URL                | Realtime       |
| Need to reprocess deliveries via logs             | Webhook        |