# Client (/docs/reference/client)



## `createEmailClient(options)` [#createemailclientoptions]

Creates an email client.

```ts
const email = createEmailClient({
  adapters,
  defaultAdapter,
  fallback,
  retry,
  hooks,
});
```

| Option            | Type               | Default              |
| ----------------- | ------------------ | -------------------- |
| `adapters`        | `EmailProvider[]`  | Required             |
| `providers`       | `EmailProvider[]`  | Alias for `adapters` |
| `defaultAdapter`  | `string`           | First adapter        |
| `defaultProvider` | `string`           | First adapter        |
| `fallback`        | `string[]`         | `[]`                 |
| `retry`           | `EmailRetryConfig` | No retries           |
| `hooks`           | `EmailHooks`       | No hooks             |

Routing names must be unique.

## `email.send(message, options?)` [#emailsendmessage-options]

Sends one message.

```ts
const result = await email.send(message, {
  adapter: "resend",
  fallbackAdapters: ["smtp"],
  retries: 2,
  idempotencyKey: "receipt:order_123",
  metadata: {
    route: "checkout.receipt",
  },
});
```

| Option              | Type                      | Notes                                     |
| ------------------- | ------------------------- | ----------------------------------------- |
| `adapter`           | `string`                  | Override the default routing name.        |
| `provider`          | `string`                  | Alias for `adapter`.                      |
| `fallbackAdapters`  | `string[]`                | Override fallback adapters for this send. |
| `fallbackProviders` | `string[]`                | Alias for `fallbackAdapters`.             |
| `retries`           | `number`                  | Override retry count for this send.       |
| `signal`            | `AbortSignal`             | Abort provider work when supported.       |
| `idempotencyKey`    | `string`                  | Passed to adapters that support it.       |
| `metadata`          | `Record<string, unknown>` | Passed to hooks.                          |

## `email.sendBatch(messages, options?)` [#emailsendbatchmessages-options]

Sends messages one at a time and returns one result per item.

```ts
const results = await email.sendBatch([messageA, messageB]);
```

`sendBatch` does not throw for the first failed item. Failed sends are returned as `{ ok: false, index, error }`.

## `email.adapter(name)` [#emailadaptername]

Returns a registered adapter or throws `EmailProviderNotFoundError`.

```ts
const resendAdapter = email.adapter("resend");
```

`email.provider(name)` is kept as an alias.

## `email.withAdapter(name)` [#emailwithadaptername]

Returns a small client bound to one adapter.

```ts
const transactional = email.withAdapter("postmark");

await transactional.send(message);
```

`email.withProvider(name)` is kept as an alias.