Node.js SDK

Send email with Railway

Deploy a small Parcel Wing-powered email service on Railway using environment variables for secrets.

Install the SDK

The official SDK is published as @parcelwing/node.

Terminal

npm install @parcelwing/node

Variables

Add your Parcel Wing API key and default sender to Railway Variables. Railway exposes service variables to your app at runtime as environment variables.

Railway Variables

PARCEL_WING_API_KEY=pw_live_...
PARCEL_WING_FROM_EMAIL="Acme <[email protected]>"

Email endpoint

Create a small server that reads Railway's PORT variable and sends mail from a trusted backend endpoint.

src/server.ts

import express from "express";
import { ParcelWing, ParcelWingError } from "@parcelwing/node";
 
const app = express();
const parcelWing = new ParcelWing({
  apiKey: process.env.PARCEL_WING_API_KEY!,
});
 
app.use(express.json());
 
app.get("/health", (_req, res) => {
  res.json({ ok: true });
});
 
app.post("/send", async (req, res) => {
  try {
    const [message] = await parcelWing.emails.send({
      from: process.env.PARCEL_WING_FROM_EMAIL!,
      to: req.body.email,
      template_alias: "welcome_email",
      template_params: {
        first_name: req.body.firstName ?? "friend",
      },
    });
 
    res.json({ id: message?.id });
  } catch (error) {
    if (error instanceof ParcelWingError) {
      res.status(error.status).json({
        code: error.code,
        requestId: error.requestId,
      });
      return;
    }
 
    res.status(500).json({ error: "Unexpected error" });
  }
});
 
const port = Number(process.env.PORT ?? 3000);
app.listen(port, () => {
  console.log("Server listening on " + port);
});

Deployment

Use a build script and start script so Railway can build TypeScript and run the compiled server.

package.json

{
  "scripts": {
    "start": "node dist/server.js",
    "build": "tsc"
  },
  "dependencies": {
    "@parcelwing/node": "latest",
    "express": "latest"
  },
  "devDependencies": {
    "@types/express": "latest",
    "typescript": "latest"
  }
}

Production notes

Keep PARCEL_WING_API_KEY in Railway Variables, not in source control.
Add authentication, rate limiting, or bot protection before exposing public sending endpoints.
Use a verified sending domain before sending production email.