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

# Attachments

> Add file attachments and inline assets to emails sent with Dugble.

Dugble supports attachments on individual email sends. Attachment content must be provided as Base64-encoded data.

## Attachment fields

Each attachment can include:

* `filename` — required name shown to the recipient.
* `content` — required Base64-encoded file content.
* `content_type` — optional MIME type, such as `application/pdf`.
* `content_id` — optional identifier for inline content referenced from HTML.

<Warning>
  Attachment paths and remote URLs are not supported. Provide Base64 content directly in the request.
</Warning>

## Example

```json theme={null}
{
  "from": "Dugble <notifications@example.com>",
  "to": "ada@example.com",
  "subject": "Your invoice",
  "html": "<p>Your invoice is attached.</p>",
  "attachments": [
    {
      "filename": "invoice.pdf",
      "content": "JVBERi0xLjQK...",
      "content_type": "application/pdf"
    }
  ]
}
```

## Size limit

The combined decoded size of all attachments in one email can be up to 7 MB. Dugble rejects requests that exceed this limit.

Base64 increases the size of data on the wire, so account for the encoded payload size when building requests.

## Inline content

Use `content_id` when an attachment should be referenced inside the HTML body, for example for an embedded image.

```html theme={null}
<img src="cid:company-logo" alt="Company logo" />
```

The corresponding attachment uses the same identifier:

```json theme={null}
{
  "filename": "logo.png",
  "content": "iVBORw0KGgo...",
  "content_type": "image/png",
  "content_id": "company-logo"
}
```

## Batch sending

<Warning>
  Attachments are not supported by `POST /emails/batch`. Send messages with attachments individually using `POST /emails`.
</Warning>

For independent messages without attachments, see [Batch Sending](/docs/emails/batch-sending).