Node.js SDK

Send email with SvelteKit

Use Parcel Wing from SvelteKit server actions while keeping API keys server-only.

Install the SDK

The official SDK is published as @parcelwing/node.

Terminal

npm install @parcelwing/node

Server action

Put sending logic in +page.server.ts so the API key never ships to the browser.

src/routes/invite/+page.server.ts

import { fail, type Actions } from "@sveltejs/kit";
import { ParcelWing, ParcelWingError } from "@parcelwing/node";
 
const parcelWing = new ParcelWing({ apiKey: process.env.PARCEL_WING_API_KEY! });
 
export const actions = {
  sendWelcome: async ({ request }) => {
    const formData = await request.formData();
 
    try {
      const [message] = await parcelWing.emails.send({
        from: "Acme <[email protected]>",
        to: String(formData.get("email") ?? ""),
        template_alias: "welcome_email",
        template_params: { first_name: String(formData.get("firstName") ?? "friend") },
      });
 
      return { id: message?.id };
    } catch (error) {
      if (error instanceof ParcelWingError) {
        return fail(error.status, { code: error.code, requestId: error.requestId });
      }
 
      return fail(500, { error: "Unexpected error" });
    }
  },
} satisfies Actions;

Production notes

Keep PARCEL_WING_API_KEY in server-only environment variables.
Validate recipient addresses and public form input before sending.
Use saved templates for onboarding, invites, receipts, and other repeatable lifecycle email.