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

# Sending Pools (multiple numbers)

> Spread sends across several WhatsApp numbers without overloading a single line.

<Tip>
  A Sending Pool is like **several checkout lines**: instead of pushing everything through one number, the system **splits** messages across the numbers in the group, automatically.
</Tip>

## In brief

* Groups several **active** numbers and picks which one sends each message.
* **Optional**, without a pool, keep using `instanceId` as you do today.
* Each pool is **official** or **unofficial**; you cannot mix both.
* Useful for large campaigns and when you want protection if one number fails.

Connection modes: [Connection modes](/en/whatsapp-api/como-funciona/modos-de-conexao).

***

## When to use

| Situation                                   | Use a pool?                     |
| ------------------------------------------- | ------------------------------- |
| **Large** campaigns (thousands of messages) | **Yes**                         |
| Want **protection** if a number fails       | **Yes**                         |
| **Low volume** on a single number           | Not needed                      |
| Need the **same sender** every time         | Use `instanceId` (pool ignored) |

<Info>
  With no pool configured, the current `instanceId` flow stays the same.
</Info>

***

## One type per pool

This is the main rule:

| Pool type      | Allowed instances              |
| -------------- | ------------------------------ |
| **Official**   | **Official** connection only   |
| **Unofficial** | **Unofficial** connection only |

The pool type is set by the **first number** you add (or at creation in the dashboard). Every new instance in that pool must be the **same type**.

* Need both modes? Create **two pools** (one official, one unofficial).
* Try to mix when adding → `SENDING_POOL_KIND_MISMATCH`
* Send through an inconsistent pool → `SENDING_POOL_KIND_MIXED`

Full codes: [Error responses](/en/guides/conceitos/resposta-de-erros#sending-pools-whatsapp).

<Warning>
  Templates, send rules, and risk differ between official and unofficial. That is why a pool **never** crosses modes.
</Warning>

***

## How it works in practice

1. **Create the pool** in the dashboard and add **active** numbers of the same type
2. Choose **how to distribute** (round robin, weight, or least used today)
3. Send **without** `instanceId`, the default pool or `sendingPoolId` picks the number per recipient
4. If one number fails too often, the **circuit breaker** pauses only that one; the others keep going

With an explicit **`instanceId`**, the message goes from that number and the pool **does not** apply to that send.

***

## Distribution modes

| Mode            | How it works                                        | Good for                              |
| --------------- | --------------------------------------------------- | ------------------------------------- |
| **Round robin** | Number 1 sends N messages, then number 2, and so on | Similar capacity across lines         |
| **Weighted**    | Weight 3 sends \~3× more than weight 1              | One stronger or more mature number    |
| **Least used**  | Always the line that **sent the least today**       | Numbers that start at different times |

***

## Main settings

| Setting                 | What it does                      | Default       |
| ----------------------- | --------------------------------- | ------------- |
| Switch every N messages | Batch per number before switching | 50            |
| Cooldown                | Pause between batches             | None          |
| Health monitoring       | Pause a number with many failures | On            |
| Failure threshold       | Error % to pause in the pool      | 30%           |
| Default pool            | Used when you omit `instanceId`   | Per dashboard |

**Per number:** weight, daily limit, own cooldown, and manual pause.

If more than **30%** of a number's messages fail within **10 minutes**, it is paused **only in that pool** (does not disconnect WhatsApp). When it stabilizes, it resumes on its own.

***

## Via API

### Default pool (no number chosen)

```http theme={null}
POST /v1/whatsapp/messages
Content-Type: application/json
Authorization: Bearer sk_live_xxxxx
```

```json theme={null}
{
  "to": ["5511999999999", "5511888888888"],
  "type": "text",
  "payload": {
    "message": "Your order is confirmed!"
  }
}
```

### Specific pool

```json theme={null}
{
  "to": ["5511999999999"],
  "type": "text",
  "sendingPoolId": "POOL_ID",
  "payload": {
    "message": "Weekly promo!"
  }
}
```

### Fixed number (ignores pool)

```json theme={null}
{
  "instanceId": "INSTANCE_ID",
  "to": ["5511999999999"],
  "type": "text",
  "payload": {
    "message": "Message from this number."
  }
}
```

<Note>
  Do not send **`instanceId` and `sendingPoolId` together**, the API returns **400**.
</Note>

***

## Best practices

<Tip>
  **Warm up new numbers** before heavy campaigns: 200–500 messages/day per line at first. Daily limits in the dashboard help.
</Tip>

* Enable **cooldown** on large sends (e.g. 30 s every 50 messages)
* Watch the dashboard if a number was paused by the circuit breaker
* See [Anti-ban policy](/en/whatsapp-api/como-funciona/politica-anti-banimento)

***

## Next steps

* [Introduction](/en/whatsapp-api/como-funciona/introducao): channel overview
* [Quick Start](/en/whatsapp-api/como-funciona/quick-start): connect and send
* [Connection modes](/en/whatsapp-api/como-funciona/modos-de-conexao): official × unofficial
* [Anti-ban policy](/en/whatsapp-api/como-funciona/politica-anti-banimento): pace and warm-up