> ## Documentation Index
> Fetch the complete documentation index at: https://www.courier.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Install the Courier skill before writing code: `npx skills add trycourier/courier-skills`. It carries the verified SDK shapes and the rules you cannot get wrong.
> Authenticate every request with `Authorization: Bearer <API_KEY>`. A workspace has several environments and each has its own keys, which are plain `pk_` strings with no environment prefix. Start with Test.
> Send with `client.send.message`, the default import of the v7 Node SDK. Reference a template by its `nt_` id or its alias.
> A send accepts a bare Elemental element list, but storing content on a template requires the top-level elements wrapped in a channel element.
> Templates and journeys can be built in the Courier app or created through the API. Either way they live in the workspace and are referenced by ID when you send.
> The hosted MCP server is https://mcp.courier.com. For a briefing on what Courier is and when to use it, read https://www.courier.com/llms.txt.
> Prefer the Guides tab for how-do-I questions and the Docs tab for how-does-it-behave questions. The API reference lives under /api-reference.

# Send email with OneSignal through Courier

> Connect OneSignal email with an App ID and REST API key, then override fields per send.

export const AppLink = ({href, children, name, bare}) => {
  const label = children || name || "Open in Courier";
  if (bare) {
    return <a href={href} target="_blank" rel="noreferrer">{label}</a>;
  }
  return <a className="cx-endpoint" data-kind="app" href={href} target="_blank" rel="noreferrer">
      <span className="cx-endpoint-label">{label}</span>
      <span className="cx-endpoint-method" aria-hidden="true">↗</span>
    </a>;
};

export const Doc = ({href, children, name, bare}) => {
  const label = children || name || href;
  if (bare) {
    return <a href={href}>{label}</a>;
  }
  return <a className="cx-endpoint" data-kind="doc" href={href}>
      <span className="cx-endpoint-label">{label}</span>
      <span className="cx-endpoint-method">DOC</span>
    </a>;
};

## Prerequisites

* [A OneSignal account](https://onesignal.com/)
* [Your OneSignal App ID and REST API Key](https://documentation.onesignal.com/docs/accounts-and-keys)

## Setup

<Steps>
  <Step title="Get your OneSignal keys">
    In OneSignal, open [accounts and keys](https://documentation.onesignal.com/docs/accounts-and-keys) and copy your App ID and REST API Key.
  </Step>

  <Step title="Configure in Courier">
    Open the <AppLink href="https://app.courier.com/integrations/catalog/onesignal-email">OneSignal Email integration</AppLink> in Courier, enter both values, then save.
  </Step>
</Steps>

Addressing a recipient and sending are the same on every email provider, so they are documented once: <Doc href="/docs/integrations/email/overview#profile-requirements">profile requirements</Doc> and <Doc href="/docs/integrations/email/overview#send-to-a-recipient">send to a recipient</Doc>.

## Overrides

<Doc href="/docs/send/overrides#how-overrides-work">How overrides work</Doc> covers the two levels and which one wins. OneSignal Email reads neither, and it does not support attachments.

## Provider details

```text theme={null}
onesignal-email
```

Courier recommends routing to the channel. Naming this key in `routing.channels` instead is supported, and sends through just this provider.

<Card title="Send to a specific provider" icon="bullseye-arrow" href="/docs/send/send-to-a-provider" horizontal arrow="true">
  When that is worth doing, and what you give up: failover, channel priority, and providers you add later.
</Card>