coss.comdocs

Download a file

GET
/v1/forms/{id}/submissions/{submission_id}/files/{file_id}

A file uploaded with the submission, as application/octet-stream: whatever its type, treat it as untrusted (a submitter chose it).

Authorization

bearerAuth
headerAuthorizationBearer <token>

A secret API key from the dashboard: coss_live_… for production environments, coss_test_… for sandbox environments.

Path Parameters

id*string

The form's id.

submission_id*string

The submission's id.

file_id*string

The file's id (files[].id of the submission).

Header Parameters

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"

Response Body

The file's bytes.

response?fileapplication/octet-stream
Formatbinary
import { Coss } from "coss";const coss = new Coss({  apiKey: process.env.COSS_API_KEY,  baseUrl: "https://api.coss.com",});const { data, error } = await coss.forms.submissions.file("form_01kd2m8n3p4q5r6s7t8v9w0x1y", "fsub_01kd2m9a0b1c2d3e4f5g6h7j8k", "ffile_01kd2m9a0b1c2d3e4f5g6h7j8m");
"string"