Email
Inboxes
- List inboxes GET
- Create an inbox POST
- Retrieve an inbox GET
- Update an inbox PATCH
- Delete an inbox DELETE
- List an inbox's threads GET
- Retrieve a thread GET
- Delete a thread DELETE
- List an inbox's messages GET
- Send a message from an inbox POST
- Retrieve a message GET
- Download an attachment of a message GET
- Reply to a message POST
Marketing
SMS
Sign
Hooks
Risk
Platform
Download an attachment of a message
GET
/v1/inboxes/{inbox_id}/messages/{message_id}/attachments/{attachment_id}
An inbound message's attachment, always as application/octet-stream (its declared type is the attachment's content_type): treat it as untrusted.
bearerAuthheader
AuthorizationBearer <token>A secret API key from the dashboard: coss_live_… for production environments, coss_test_… for sandbox environments.
inbox_id*stringThe inbox's id.
message_id*stringThe message's id.
attachment_id*stringThe attachment's id (from the message's attachments).
Coss-Version?"2026-10-10"The API version (a date) to use for this request. Defaults to your organization's version, pinned to the latest one when it first used the API and upgraded from the dashboard. The SDK always sends the version it was built for.
Value in
"2026-10-10"The attachment.
response?fileapplication/octet-streamFormat
binaryimport { Coss } from "coss";const coss = new Coss({ apiKey: process.env.COSS_API_KEY, baseUrl: "https://api.coss.com",});const { data, error } = await coss.inboxes.messages.getAttachment("inbox_01k7c8m4q2f3e9v6t5r1n0p8yz", "imsg_01k7c8m4s1d3c9x0z4e6g7h8j9", "rcvdatt_01k7c8m4r0c2b8w9y3d5f6g7h8");"string"