Yes.
from: Attachment
select:
- Name
- ContentType
- Content
The Blob field (Content) is returned as Base64
[
[
{
"_oid": "Attachment:1783",
"Name": "Attachment A",
"ContentType": "text/plain",
"Content": "VGhpcyBpcyB ...base64 encoded bytes here... hdHRhY2htZW50"
}
]
]