Examples

Example application patterns for OpenSend. Start with the SDK or framework guide that matches your runtime, then adapt the sender domain, base URL, and secret storage to your deployment.

Raw markdown

Published npm package

Send one email with opensend: minimal Node/Bun example that installs the published npm package, reads local environment variables, and sends one test email.

SDK quickstarts

Framework quickstarts

Runtime and deployment quickstarts

When to use each sending surface

Surface	Use it when	Avoid it when
SDK / REST `/emails`	Transactional mail such as signups, receipts, invites, passwordless auth, alerts	You need to send one campaign to a large audience
`/emails/batch`	You have a small set of transactional messages to queue together	You need segmentation, unsubscribe topics, or campaign reporting
Broadcasts	You are sending campaign or lifecycle mail to contacts/segments	You need a one-off transactional response inside a request
SMTP relay	A legacy app only supports SMTP	You need templates, scheduling, or direct API response details

Environment checklist

Every example expects:

bash

OPENSEND_API_KEY=os_your_api_key
# Optional for self-hosted deployments:
OPENSEND_BASE_URL=https://opensend.namuh.co

Use a verified sending domain before production sends. Use idempotency keys for flows that can retry.