Send Email

Send one email through OpenSend.

POST /emails

Authentication

Use an OpenSend API key in the Authorization header.

http

Authorization: Bearer os_YOUR_API_KEY

Dashboard session cookies are not API credentials.

Body

Required fields:

from — sender address, optionally with a display name.
to — recipient string or array.
subject — subject line.
html, text, react, or template content depending on client path.

Optional fields include cc, bcc, reply_to, headers, attachments, tags, scheduled_at, and topic_id.

Example

bash

curl -X POST https://opensend.namuh.co/emails \
  -H "Authorization: Bearer os_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: welcome-001" \
  -d '{"from":"Acme <onboarding@example.com>","to":["user@example.com"],"subject":"Welcome","html":"<p>Hello</p>"}'

Response

json

{ "id": "email_id" }