RCS NEWSLETTER is for bulk, opted-in rich messaging to subscribed users. Billing is a single MAU charge per subscribed user per agent per calendar month — there is no per-message charge on top.
ChargeWhen
MAUOnce per subscriber per agent per calendar month — triggered on the first send that month
MAU fires on the first send of the month. Subsequent sends to the same subscriber within the same calendar month carry no additional charge (mau_charged: false, hold_amount: 0). Daily send limit — you can send at most one message per day per subscriber. A second send on the same calendar day returns 429. Because billing fires only once per month and sends are limited to once per day, the maximum sends per subscriber per month equals the number of days in that month.
The newsletter channel (message_type: NEWSLETTER) must be enabled during agent setup — it is a flag you set when creating the agent before submitting for review. If your agent was created without this flag, you need a new agent with newsletter enabled and must go through approval again. See RCS agents.

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Request

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Authorization
string
required
Bearer <api_key>
​
Idempotency-Key
string
UUID to prevent duplicate sends on retry.

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Body

{
  "to": "+4917612345678",
  "agent_id": "ag_live_xxxx",
  "message_type": "NEWSLETTER",
  "content": {
    "rich_card": {
      "standalone": {
        "orientation": "VERTICAL",
        "content": {
          "title": "Weekly deals",
          "description": "Members save 20% this weekend",
          "media": {
            "url": "https://cdn.arowana.app/deals-banner.jpg",
            "height": "TALL"
          },
          "suggestions": [
            { "action": { "text": "View deals", "open_url": { "url": "https://shop.arowana.app/deals" } } }
          ]
        }
      }
    }
  },
  "traffic_type": "PROMOTION"
}
​
to
string
required
Destination phone number in international format (e.g. +4917612345678). The user must be a subscribed contact with valid consent for this agent’s newsletter channel.
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agent_id
string
required
Production agent id. The agent must have newsletter/MAU enabled — see the warning above.
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message_type
string
required
NEWSLETTER — required for this billing path.
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content
object
required
Rich card or carousel content — see RCS rich card and RCS carousel. Plain text is also accepted.
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traffic_type
string
required
PROMOTION for newsletter traffic in most markets.

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Responses

MAU is charged on the first send to this subscriber in the current calendar month.
{
  "message_id": "msg_nl_d4e5f6",
  "status": "queued",
  "created_at": "2026-03-28T09:00:00Z",
  "billing": {
    "channel": "RCS",
    "message_type": "mau",
    "mau_charged": true,
    "hold_amount": 0.15,
    "balance": {
      "free": 49.85,
      "reserved": 0.15,
      "total": 50.00
    },
    "tier": {
      "channel": "RCS",
      "current": "tier_1",
      "volume_used": 251
    }
  }
}
​
billing.message_type
string
mau — newsletter billing is always MAU; there is no per-message charge.
​
billing.mau_charged
boolean
true — this subscriber had not yet been charged MAU this month for this agent. The MAU charge is the full hold_amount.
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billing.hold_amount
number
The MAU charge for this subscriber. Resolves as a debit when the message is accepted by the network.
​
billing.tier
object