Read one part of a message
An attachment or a body part, returned inline.
mode: text (the default) renders a part that is already text —
text/*, JSON, XML, a forwarded message — the way a message body is
rendered, under the same banner and with the same defences; HTML is
converted to text. At most the first 2 MiB of the part is read: a longer
one comes back cut, with truncated, and there is no cursor to continue
from. Any other type is unavailable in this mode: read it with
mode: bytes.
mode: bytes returns the part’s decoded bytes, standard base64, as
content.bytes_base64, beside its type, filename and size. A part too large to return whole is refused with
422 policy_refused and guard: part_size rather than cut short. A
message withheld because it carries malware refuses every part, in
either mode, with guard: virus.
Authorizations
Bearer credential for one agent: an API key or an access
token (a JWT). Pass as Authorization: Bearer <credential>.
A key is shown once when it is issued and is not recoverable afterwards; an access token lives five minutes and is fetched with the agent's own client key from the access service. Treat both as secrets: they reach one agent's mail, and anything a delegation has extended to it. An access token's scope is a ceiling on what the agent may do with it.
Body
Response
The object.

