Installation

bash

npm install render25

Or using yarn, pnpm, or bun:

bash

yarn add render25
pnpm add render25
bun add render25

Basic Usage

Initialize the client by passing your API key or automatically reading from process.env.RENDER25_API_KEY.

send-email.ts

import { Render25 } from "render25";

const render25 = new Render25(); // Automatically uses process.env.RENDER25_API_KEY

const { id } = await render25.emails.send({
  from: "support@yourdomain.com",
  to: "user@example.com",
  subject: "Welcome to Render25!",
  html: "<h1>Welcome aboard!</h1><p>Your transactional email was delivered instantly.</p>",
  text: "Welcome aboard! Your transactional email was delivered instantly.",
});

console.log("Email dispatched with ID:", id);

Note

Set RENDER25_API_KEY in your environment variables. Never commit raw API keys to version control.

CC, BCC & Custom Reply-To

Render25 allows you to specify multiple recipients, CC copies, secret BCC copies, and custom Reply-To routing.

advanced-send.ts

import { Render25 } from "render25";

const render25 = new Render25();

await render25.emails.send({
  from: "support@yourdomain.com",
  to: ["primary@example.com"],
  cc: ["manager@example.com", "billing@example.com"],
  bcc: ["compliance-archive@example.com"],
  replyTo: "helpdesk@yourdomain.com",
  subject: "Invoice #1042 Ready",
  html: "<p>Your monthly invoice is ready for review.</p>",
});

File Attachments

Attach PDF invoices, spreadsheets, images, or documents by passing a Node.js Buffer or a Base64 string.

send-with-attachment.ts

import { Render25 } from "render25";
import fs from "fs";

const render25 = new Render25();

await render25.emails.send({
  from: "support@yourdomain.com",
  to: "client@example.com",
  subject: "Your Monthly Receipt & Statement",
  html: "<p>Please find your receipt and statement attached below.</p>",
  attachments: [
    {
      filename: "invoice_1042.pdf",
      content: fs.readFileSync("./invoice.pdf"), // Buffer automatically encoded to Base64
      contentType: "application/pdf",
    },
    {
      filename: "report.csv",
      content: Buffer.from("Date,Amount\n2026-08-01,$49.00").toString("base64"),
      contentType: "text/csv",
    }
  ]
});

TypeScript Support

Full types and interfaces are included out of the box — no extra @types package needed.

types.ts

import { Render25, SendEmailOptions, SendEmailResponse } from "render25";

const client = new Render25();

const options: SendEmailOptions = {
  from: "notifications@yourdomain.com",
  to: "user@example.com",
  subject: "System Alert",
  html: "<p>All systems operational.</p>",
};

const response: SendEmailResponse = await client.emails.send(options);
console.log(response.id);

Framework Examples

Next.js

App Router API Routes & Server Actions

Express

Use in Express route controllers

app/api/send/route.ts

import { Render25 } from "render25";
import { NextResponse } from "next/server";

const render25 = new Render25();

export async function POST(req: Request) {
  try {
    const { to, subject, html } = await req.json();

    const data = await render25.emails.send({
      from: "notifications@yourdomain.com",
      to,
      subject,
      html,
    });

    return NextResponse.json(data);
  } catch (error: any) {
    return NextResponse.json({ error: error.message }, { status: 500 });
  }
}

Node.js / TypeScript SDK