kudosity-rcslisted

# Send RCS Messages RCS is rich, branded messaging delivered in the recipient's native messaging app. Kudosity sends RCS over the V2 API. > **Beta.** The RCS endpoints are marked beta in the Kudosity API and may change. Check `https://developers.kudosity.com` before relying on a field not listed here. ## The one thing that trips people up **RCS does not send from a phone number.** Unlike SMS, MMS and WhatsApp, the `sender` field is a **registered RCS agent ID** — alphanumeric or numeric, e.g. `DemoSender`. If you pass a phone number, the send fails validation. An agent must be registered and launched on the destination carrier before it will deliver. Registration is not part of this API — talk to your Kudosity account contact to get an agent provisioned, then use its ID here. ## Authentication - Header: `x-api-key: {KUDOSITY_API_KEY}` - Base URL: `https://api.transmitmessage.com` ## Send an RCS message **Endpoint:** `POST /v2/rcs/messages` Required: - `sender` (string) — your registered RCS agent ID - `recipient` (string) — destination number, local or [E.164](https://en.wikipedia.org/wiki/E.164) format (`0438 333 061` → `61438333061`) - `content_type` (string) — currently only `text` - `content` (object) — `{ "text": { "message": "..." } }` Optional: - `sms_fallback` (object) — see below. **Use this on almost every send.** - `message_ref` (string, max 500 chars) — your reference, echoed back in webhook events ### Message length - **Basic RCS** — up to 160 charac