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

# Messenger Overview

> Facebook Messenger and Marketplace chat messaging through your Facebook Page

The Messenger channel lets you receive and reply to Facebook Messenger conversations — including **Facebook Marketplace chats** — through your Facebook Page, using the same unified API as every other Zavu channel.

## When to Use Messenger

* **Marketplace sellers**: Reply to buyer inquiries on your listings, automatically or from the Inbox
* **Customer support**: Handle Page messages alongside WhatsApp, SMS, and Email in one place
* **AI agents**: Let a Zavu AI Agent answer Messenger conversations 24/7

## Basic Messenger Message

<CodeGroup>
  ```typescript TypeScript theme={null}
  const result = await zavu.messages.send({
    to: "24025631120151183", // Messenger user ID (PSID)
    text: "Thanks for your message!",
    channel: "messenger",
  });
  ```

  ```python Python theme={null}
  result = zavu.messages.send(
      to="24025631120151183",  # Messenger user ID (PSID)
      text="Thanks for your message!",
      channel="messenger"
  )
  ```

  ```ruby Ruby theme={null}
  result = client.messages.send(
    to: "24025631120151183", # Messenger user ID (PSID)
    text: "Thanks for your message!",
    channel: "messenger"
  )
  ```

  ```go Go theme={null}
  result, _ := client.Messages.Send(context.TODO(), zavudev.MessageSendParams{
  	To:      zavudev.String("24025631120151183"), // Messenger user ID (PSID)
  	Text:    zavudev.String("Thanks for your message!"),
  	Channel: zavudev.String("messenger"),
  })
  ```

  ```php PHP theme={null}
  $result = $client->messages->send([
      'to' => '24025631120151183', // Messenger user ID (PSID)
      'text' => 'Thanks for your message!',
      'channel' => 'messenger',
  ]);
  ```

  ```bash cURL theme={null}
  curl -X POST https://api.zavu.dev/v1/messages \
    -H "Authorization: Bearer $ZAVU_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "to": "24025631120151183",
      "text": "Thanks for your message!",
      "channel": "messenger"
    }'
  ```
</CodeGroup>

## Facebook Marketplace Chats

When a buyer messages your Page from a Marketplace listing, the conversation arrives through the same Messenger channel:

1. A buyer taps **Message** on your Marketplace listing
2. Zavu receives the message via your connected Facebook Page and creates a contact + conversation
3. You receive a `message.inbound` webhook (or your AI Agent replies automatically)
4. Reply from the Inbox, via the API, or let your agent handle it

<Note>
  Marketplace conversations follow the same rules as regular Page messages: same user IDs, same 24-hour window, same API.
</Note>

## User IDs vs Phone Numbers

Like Telegram and Instagram, Messenger uses numeric user IDs (PSIDs — Page-Scoped IDs) instead of phone numbers:

```
Phone-based channels:  +14155551234
Messenger:             24025631120151183
```

<Warning>
  You cannot message a Messenger user by phone number. The user must message your Page first — their PSID arrives in the `from` field of the inbound message (prefixed as `messenger:{id}` in contacts and conversations).
</Warning>

PSIDs are scoped per Page: the same person has a different ID for each Facebook Page they talk to.

## 24-Hour Messaging Window

Messenger enforces a standard messaging window:

* You can reply freely within **24 hours** of the user's last message
* Outside the window, Meta rejects the send and the message fails with a clear error
* There are no pre-approved templates like WhatsApp — the user must message again to reopen the window

## Message Types

| Type     | Use Case              |
| -------- | --------------------- |
| Text     | Simple replies        |
| Image    | Photos and graphics   |
| Video    | Video clips           |
| Audio    | Voice notes           |
| Document | Files and attachments |

## Delivery Status

| Status    | Description                           |
| --------- | ------------------------------------- |
| `queued`  | Message accepted by Zavu              |
| `sending` | Being sent to Meta                    |
| `sent`    | Accepted by Messenger                 |
| `failed`  | Delivery failed (e.g., window closed) |

## Setup Requirements

Before sending Messenger messages, you need to:

1. A Facebook Page (the Page your Marketplace listings or business uses)
2. Connect the Page in your Zavu sender settings via Meta login

See [Messenger Setup](/guides/messenger/setup) for detailed instructions.

## Common Errors

| Error                                                | Cause                       | Solution                              |
| ---------------------------------------------------- | --------------------------- | ------------------------------------- |
| `24-hour messaging window closed`                    | User hasn't messaged in 24h | Wait for the user to message again    |
| `Messenger requires a Facebook Page to be connected` | Channel not configured      | Connect a Page in sender settings     |
| `Invalid user ID`                                    | Wrong PSID                  | Use the PSID from the inbound message |

## Next Steps

* [Messenger Setup](/guides/messenger/setup) - Connect your Facebook Page
* [Receiving Messages](/guides/receiving-messages/webhooks) - Handle inbound webhooks
* [AI Agents](/guides/ai-agents/overview) - Auto-reply to Messenger chats