NexSend

The official SDK for NexSend — the Cloudflare-native transactional email platform. Send transactional email from anywhere your code runs: Cloudflare Workers, Node 18+, Deno, Bun, or the browser. Zero dependencies — it only needs a fetch.

Before you start

The SDK talks to your NexSend account, so set that up first:

1. Create an account → https://dev.nexb.me/ Sign up (passwordless magic link), then sign in to the dashboard.
2. Verify a sending domain. In the dashboard, add the domain you'll send from and follow the DNS steps until it shows verified. You can only send from a domain your account has verified.
3. Create an API key. Generate a key in the dashboard — it's shown once, so copy it. This is the apiKey you pass to the SDK.
4. Read the docs. The full guides, request/response reference, and live examples live in the dashboard under Docs (https://dev.nexb.me/docs).

Once your domain is verified and you have an API key, install the SDK and send.

Install

npm install @nexsend/sdk
# or
pnpm add @nexsend/sdk

Quick start

import { NexSend } from "@nexsend/sdk";

const ns = new NexSend({ apiKey: process.env.NEXSEND_API_KEY });

const { data, error } = await ns.emails.send({
  from: "[email protected]", // must be a verified domain
  to: "[email protected]",
  subject: "Hello",
  html: "<p>Hi there</p>",
});

if (error) {
  console.error(error.code, error.message);
} else {
  console.log("queued", data.id, data.status);
}

Every method returns { data, error } — it never throws on an API error (only on network/programmer errors). Inspect error for { code, message, status }.

Options

new NexSend({
  apiKey: "cm_live_...",      // required — created in the dashboard
  baseUrl: "https://...",     // default https://dev-api.nexb.me
  maxRetries: 2,              // 429/5xx retries for idempotent requests
  fetch: globalThis.fetch,    // custom fetch (e.g. undici)
});

CLI (npx)

The same package ships a CLI, so you can send mail and inspect your account without writing any code. Authenticate with the NEXSEND_API_KEY env var (or pass --api-key):

# Send an email
NEXSEND_API_KEY=cm_live_... npx @nexsend/sdk send \
  --from [email protected] \
  --to [email protected] \
  --subject "Hello" \
  --text "Hi there"

# Inspect your account
npx @nexsend/sdk emails list --limit 5
npx @nexsend/sdk emails get cm_email_123
npx @nexsend/sdk domains list
npx @nexsend/sdk api-keys list

# Machine-readable output
npx @nexsend/sdk emails list --json

Run npx @nexsend/sdk --help for the full command list. Every command exits non-zero on error.

API surface

| Resource | Methods | | ------------- | ---------------------------------------------------- | | emails | send, get, list | | domains | create, list, verify, setupDns, delete | | apiKeys | create, list, revoke | | suppressions| list, remove |

Idempotent sends

send only retries on 429/5xx when you pass an idempotency key:

await ns.emails.send(input, { idempotencyKey: crypto.randomUUID() });

Links

• Dashboard & sign-up: https://dev.nexb.me/
• Docs: https://dev.nexb.me/docs

License

MIT