# WhatsApp sticker messages

A sticker message carries a public WebP URL WhatsApp fetches at send time. It's the plainest media arm: no caption, no other optional field on send.

## Send a sticker

Set `sticker.url`; there is nothing else to add:

<!-- bird:tabs typescript,python,go,php,cli,curl -->

```typescript
const msg = await bird.whatsapp.send({
  to: "+16505551234",
  from: "+13124495648",
  sticker: { url: "https://cdn.example.com/stickers/thumbs-up.webp" },
});
console.log(msg.id, msg.status);
```

```python
msg = client.whatsapp.send(
    to="+16505551234",
    from_="+13124495648",
    sticker={"url": "https://cdn.example.com/stickers/thumbs-up.webp"},
)
print(msg.id, msg.status)
```

```go
package main

import (
	"context"
	"fmt"
	"log"
	"os"

	bird "github.com/messagebird/bird-sdk-go"
	"github.com/messagebird/bird-sdk-go/option"
)

func main() {
	client, err := bird.NewClient(option.WithAPIKey(os.Getenv("BIRD_API_KEY")))
	if err != nil {
		log.Fatal(err)
	}
	msg, err := client.Whatsapp.Send(context.Background(), bird.WhatsappSendParams{
		To:   "+16505551234",
		From: "+13124495648",
		Sticker: &bird.WhatsAppStickerSend{Url: "https://cdn.example.com/stickers/thumbs-up.webp"},
	})
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(msg.Id, *msg.Status)
}
```

```php
$sticker = (new WhatsAppMessageSendRequestSticker())
    ->setUrl('https://cdn.example.com/stickers/thumbs-up.webp');
$message = $bird->whatsapp->send(
    to: '+16505551234',
    from: '+13124495648',
    sticker: $sticker,
);
echo $message->getId(), ' ', $message->getStatus();
```

```cli
bird whatsapp send \
  --to +16505551234 \
  --from +13124495648 \
  --sticker https://cdn.example.com/stickers/thumbs-up.webp
```

```curl
curl -X POST "https://us1.platform.bird.com/v1/whatsapp/messages" \
  -H "Authorization: Bearer $BIRD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "to": "+16505551234",
      "from": "+13124495648",
      "sticker": {
        "url": "https://cdn.example.com/stickers/thumbs-up.webp"
      }
    }'
```

<!-- /bird:tabs -->

`sticker` has no `caption` field, and `animated` is not something you set on send; Bird only reports it back on an inbound sticker. `from` is required on every service message: a number your workspace owns, not a Bird-managed one.

## Limits

| Field               | Bound                                       | Enforced by                               |
| ------------------- | ------------------------------------------- | ----------------------------------------- |
| File size, static   | 100 KB                                      | WhatsApp only, at fetch (async)           |
| File size, animated | 500 KB                                      | WhatsApp only, at fetch (async)           |
| File type           | WebP only                                   | WhatsApp only, at fetch (async)           |
| `caption`           | not a valid field                           | Bird, at accept (`422`, schema rejection) |
| `url`               | absolute, `https`, has a host, no raw space | Bird, at accept (`422`)                   |

Bird checks the URL's shape before anything is enqueued; it does not check the file's actual size, format, or whether it's static or animated. Only WhatsApp's own fetch at send time can. Sending a `caption` is not a length error; the field doesn't exist on this arm's schema, so it fails as an unrecognized property. See the hub's [sending media by URL](/docs/guides/whatsapp/message-types#sending-media-by-url) and [when media fails](/docs/guides/whatsapp/message-types#when-media-fails).

## Reading an inbound sticker

An inbound sticker carries an `id`, `mime_type`, and `animated` Bird learned by fetching the file:

```json
{
  "id": "wam_01kya2d1isuwt4w7e1n6s9zolh",
  "direction": "inbound",
  "from": { "phone_number": "+14155550100" },
  "to": { "phone_number": "+13124495569" },
  "sticker": {
    "id": "waf_01kyb2m4xq7whs0d8n3prv6tez",
    "url": "https://platform.bird.com/v1/whatsapp/messages/wam_01kya2d1isuwt4w7e1n6s9zolh/media/waf_01kyb2m4xq7whs0d8n3prv6tez",
    "mime_type": "image/webp",
    "animated": true
  },
  "status": "received"
}
```

`id`, `mime_type`, and `animated` are all absent on an outbound read-back, since Bird never fetched or inspected the file it sent. To fetch the bytes behind an inbound sticker, see [Receiving WhatsApp messages](/docs/guides/whatsapp/receiving-whatsapp).

## Limits and failure modes

- **The customer service window has to be open.** Stickers are service messages, deliverable only inside an open window; see the hub's [customer service window](/docs/guides/whatsapp/message-types#the-customer-service-window).
- **Bird rejects `http`; WhatsApp itself would fetch it.** See the hub's [sending media by URL](/docs/guides/whatsapp/message-types#sending-media-by-url) for the full shape check.
- **A rejected fetch still gets charged.** See the hub's [when media fails](/docs/guides/whatsapp/message-types#when-media-fails). Sticker's own rejection text from WhatsApp hasn't been independently measured, so treat the mapping as inferred by symmetry rather than confirmed per cause.
- **`animated` is read-only, and only ever present on an inbound or fetched sticker.** It's WhatsApp's own verdict on the file, not something you can declare. Whether a sticker is static or animated changes only its size ceiling; WebP is required either way.
- **WhatsApp caches a fetched URL for about 10 minutes.** Resending the identical URL inside that window re-serves the first fetch; vary the URL to force a fresh one.

## Next steps

- [WhatsApp service messages](/docs/guides/whatsapp/message-types): the customer service window and the model every service message shares
- [Audio](/docs/guides/whatsapp/message-types/audio): another media arm with no caption field
- [Images](/docs/guides/whatsapp/message-types/images): for a photo or graphic with a caption
- [How sending works](/docs/guides/whatsapp/sending-whatsapp): the request envelope, the `202` model, and safe retries