Retrieve an attachment

One attachment that went out with a message, with a fresh signed link to download it.

GET /v1/emails/{email_id}/attachments/{attachment_id}

Requires a Full access API key.

Path parameters

Parameter	Type	Description
email_id	string	The email's id — a UUID.
attachment_id	string	The attachment's id, as returned by List attachments.

Example

curl

curl "https://api.sendgrail.com/v1/emails/$EMAIL_ID/attachments/$ATTACHMENT_ID" \
  -H "Authorization: Bearer $SENDGRAIL_API_KEY"

Node.js

const res = await fetch(
  `https://api.sendgrail.com/v1/emails/${emailId}/attachments/${attachmentId}`,
  { headers: { Authorization: `Bearer ${process.env.SENDGRAIL_API_KEY}` } },
);

const attachment = await res.json();

// download_url needs no API key — hand it straight to a browser
const file = await fetch(attachment.download_url);

Response

{
  "object": "attachment",
  "id": "8e0fd050-661f-4b3c-8178-c4f291d1f751",
  "filename": "invoice.pdf",
  "content_type": "application/pdf",
  "size": 20418,
  "download_url": "https://api.sendgrail.com/v1/emails/…/download?expires=…&signature=…",
  "expires_at": "2026-07-14T10:09:15+00:00"
}

Field	Type	Description
object	string	Always "attachment".
id	string	The attachment identifier — a UUID. Stable; the download_url is not.
filename	string	The name the file was sent under.
content_type	string | null	MIME type, e.g. application/pdf. null if none was recorded.
size	number	Decoded size in bytes.
download_url	string	A signed, short-lived link to the bytes — no API key required.
expires_at	string	ISO 8601 time the download_url stops working (~15 minutes out).

The download URL

download_url is the same signed, short-lived link that List attachments returns — valid for about 15 minutes, stated in expires_at. The signature is the authorisation, so the link carries no API key and can be handed straight to a browser, an <img> tag, or a customer. A leaked link exposes one file for fifteen minutes, not your account.

Fetch a fresh copy when it expires; the id is stable, the URL is not.

Errors

An attachment_id that isn't on this email returns 404 not_found — the id must belong to the email named in the path. Once an attachment is past its 30-day retention window the metadata still retrieves, but the download_url returns 404.