---
title: Template plugin
description: Render named HTML email templates before delivery.
icon: FileCode
source: "src/plugins/template.ts"
---

<Callout title="The one rule">Return a new message object from plugins; do not mutate the input.</Callout>

```ts
import { simpleEngine, templatePlugin } from "sently/plugins/template";

const plugin = templatePlugin({
  engine: simpleEngine, templates: { welcome: "<h1>Hello, {{name}}!</h1>" },
});
```

Send with `template: "welcome"` and `data: { name: "Ada" }`.

<Accordions><Accordion title="What happens to missing variables?">`simpleEngine` renders unknown variables as an empty string.</Accordion></Accordions>

<Cards><Card title="Mail options" href="/docs/reference/mail-options" /></Cards>