coss.comdocs

Add contacts to an audience

POST
/v1/audiences/{id}/contacts

Adds existing contacts, by id or address. Members already in it are counted in existing; unknown ones are listed in missing (create them first).

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 audience's id.

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"

Request Body

application/json
  1. body
contacts*array<string>

Contact ids or addresses of existing contacts.

Items1 <= items <= 1000

Response Body

What was added.

application/json
  1. response
object*"audience_contacts"
Value in"audience_contacts"
added*integer
existing*integer
missing*array<string>

Ids or addresses of no contact.

import { Coss } from "coss";const coss = new Coss({  apiKey: process.env.COSS_API_KEY,  baseUrl: "https://api.coss.com",});const { data, error } = await coss.email.audiences.addContacts("aud_01k7c8m4q2f3e9v6t5r1n0p8yz", {  contacts: [    "contact_01k7c8m4q2f3e9v6t5r1n0p8yz",    "grace@example.com",  ],});
{  "object": "audience_contacts",  "added": 1,  "existing": 0,  "missing": []}