---
title: Channels
description: Send through a stable channel API while transports handle providers.
icon: FolderOpen
source: "README.md"
---

Choose a channel sender for the kind of message your application sends.
Each sender accepts a provider transport — retry, fallback, and `SentlyError` codes stay the same as you add channels.

<Callout title="The one rule">Application code calls a sently channel sender; provider-specific code stays in its transport.</Callout>

<Steps>
  <Step title="Choose the message channel">

| Channel | Sender | Send shape |
| --- | --- | --- |
| Email | `createMailer` or `createSMTPMailer` | Sender, recipient, subject, and body. |
| SMS | `createSmsSender` | Recipient number and body. |
| WhatsApp | `createWhatsAppSender` | Template or text message. |
| Push | `createPushSender` | Web Push subscription or FCM token, plus title and body. |

  </Step>
  <Step title="Wire in a transport">

```ts
import { createSmsSender } from "sently/sms";
import { TwilioSmsTransport } from "sently/transports/twilio-sms";

const sms = createSmsSender({
  transport: new TwilioSmsTransport({
    accountSid: process.env.TWILIO_ACCOUNT_SID!,
    authToken: process.env.TWILIO_AUTH_TOKEN!,
  }),
});

await sms.send({
  to: "+15551234567",
  body: "Your order is on its way.",
  from: "+15557654321",
});
```

  </Step>
</Steps>

## Channel factories

| Factory | Async | When to use it |
| --- | --- | --- |
| `createMailer` | Yes | Email with an explicit transport. |
| `createSMTPMailer` | Yes | Email configured with SMTP host, port, and authentication. |
| `createSmsSender` | No | SMS with an `SmsTransport`. |
| `createWhatsAppSender` | No | WhatsApp with a `WhatsAppTransport`. |
| `createPushSender` | No | Web Push or FCM with a `PushTransport`. |

## Troubleshooting

<Accordions>
  <Accordion title="Should I call a provider SDK directly?">
    Use the matching sently sender for normal delivery. Provider-only features belong on the concrete transport rather than the shared channel contract.
  </Accordion>
  <Accordion title="How do I switch providers?">
    Keep the sender call and create it with a different transport for the same channel.
  </Accordion>
</Accordions>

## Learn more

- [Choose an entrypoint](../get-started/entrypoints)
- [Support matrix](../get-started/support-matrix)
- [Failover](../guides/failover)
- [Browse transports](../transports)

## Next

<Cards>
  <Card title="Email" href="/docs/channels/email" />
  <Card title="SMS" href="/docs/channels/sms" />
  <Card title="WhatsApp" href="/docs/channels/whatsapp" />
  <Card title="Push" href="/docs/channels/push" />
  <Card title="Hooks" href="/docs/channels/hooks" />
</Cards>