Cadenceβ
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RCS just reached ~70% of US phones

The conversation layer
for AI agents.

Agent-native RCS messaging with automatic SMS fallback — one API and an MCP server. We turn the carrier's 24-hour conversation into the runtime your agent lives in, and handle the 8–16-week compliance gauntlet underneath.

Start building → See how it works
1B+RCS msgs / day in the US
3–7×more engaging than SMS
~10 minto first conversation

Built on the rails behind Google RBM · Twilio · Bandwidth — abstracted into one agent-native surface.

Not a messaging API. A conversation runtime.

Twilio sells a message primitive. Infobip sells API reachability. Cadence sells the conversation — with compliance productized beneath it.

Sell the conversation, not the message

A ~15-turn agent chat is one billed 24-hour session — not a stream of metered texts. The unit Google doesn't sell, manufactured for you.

open()send()close()

RCS-first, SMS-pragmatic

Rich cards, quick-reply chips, verified sender where RCS is reachable. Automatic, seamless SMS fallback where it isn't.

MCP-native

Drop-in tools for any agent framework. Your LLM lives inside the conversation — it doesn't manage messaging infrastructure.

Compliance, productized

The 8–16-week carrier gauntlet, opt-in vault, and STOP/HELP handling — abstracted into a status bar.

Trust & safety, by default

Verified-sender branding, a pre-disclosed fallback identity so a downgrade never reads as smishing, and PHI-safe-minimal templates enforced before anything reaches the wire.

verified_rcsbranded_smsPHI-safe

Three calls to a live conversation

Agent-initiated, opt-in enforced, fallback automatic, engagement measured.

01

Open

Your agent speaks first over RCS, with opt-in provenance and a PHI-safe template. Reachability and channel are resolved for you.

02

Converse

Consumer replies — chip taps and free text — stream back as typed events. onReply fires; your agent responds.

03

Fall back & measure

Undeliverable? onFellback flips to a branded SMS automatically. Every leg is measured against your SMS baseline.

First conversation in ten minutes.

Install the SDK, drop in a key, and open an agent-initiated conversation. Rich content auto-degrades to text on the SMS leg. The channel flip is a first-class callback, not a surprise.

  • TypeScript SDK + MCP server
  • Sandbox test devices — real RCS, no carrier-launch wait
  • Usage-based. No sales call to ship.
Get your API key →
agent.ts
import { Messaging } from "@cadence/sdk";

const m = new Messaging({ apiKey: process.env.CADENCE_KEY });

const convo = await m.open({
  to: "+15551234567",
  useCase: "transactional",
  optin: { method: "appointment_booking", capturedAt },
  opening: {
    text: "Your 3pm is confirmed. Reschedule?",
    suggestions: ["Reschedule", "Cancel appt", "All good"],
  },
});

convo.onFellback(() => /* RCS → SMS, re-render as text */);
convo.onReply(async (intent) => {
  await convo.send({ text: await agent.respond(intent) });
});

The steepest curve in messaging

Apple turned RCS on. The channel inflected in the same window agents did.

0%US RCS reach, up from ~5% pre-iOS 18
0%of operator messaging revenue by 2029, from 3%
$0BA2P RCS revenue by 2029
0%global RCS traffic spike after iOS 18

Give your agents a voice consumers trust.

The conversation layer for the agent era — RCS-first, fallback-native, compliance-handled.

Start building → Talk to us