# Attachments fields

Attachment fields in Airtable expose only temporary links that expire after a certain period. To ensure persistent access to attachments, we transform them into API proxy links when syncing attachment fields.

#### Transformed Link Format

Attachment URLs are converted to this format:

```
https://eu.api-proxy-dev.stacksync.com/v1/airtable_attachment?dt=eyJiYXNlX2lXUGdEIiwgInBhdGgiOiAiIn0=
```

#### How to Use Attachment Links

1. [**Set up an API Proxy**](https://docs.stacksync.com/two-way-sync/api-proxy/airtable) - You'll receive an API key upon creation
2. **Make the request** - Include your API key in the Authorization header:

```bash
   curl -X GET "https://eu.api-proxy-dev.stacksync.com/v1/airtable_attachment?dt=eyJiYXNlX2lXUGdEIiwgInBhdGgiOiAiIn0=" \
   -H "Authorization: Bearer <your_api_key>"
```

3. **Automatic redirect** - The API proxy will:
   * Fetch the current attachment URL from Airtable
   * Redirect you to the updated link automatically

This ensures your attachment links remain valid without manual updates.