API docs

Send email

Send text or HTML email to one address or many.

POST/v1/email

Sends to one address. The email is queued and the response comes back at once with 202.

Body

tostringrequired: The recipient's email address.
subjectstringrequired: The subject. Up to 255 characters, one line.
htmlstring: The HTML body. One of html and text is required.
textstring: The plain-text body. When both are given, clients that cannot show HTML show the text.
from_namestring: The sender name. Defaults to the project's brand name, or the project name.
reply_tostring: Where replies go. Defaults to the address set in the project's settings.

curl -X POST https://api.wesend.mn/v1/email \
  -H "Authorization: Bearer $WESEND_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "to": "[email protected]",
  "subject": "Таны захиалга баталгаажлаа",
  "html": "<h1>Баярлалаа!</h1><p>Таны #1042 захиалга баталгаажлаа.</p>",
  "text": "Баярлалаа! Таны #1042 захиалга баталгаажлаа.",
  "from_name": "Shop.mn",
  "reply_to": "[email protected]"
}'

Response202 Accepted

{
  "id": "0b9c1a52-6f0e-4d8b-9a3c-2f1e5d7c8a90",
  "status": "queued",
  "channel": "email",
  "to": "[email protected]",
  "credits": 5,
  "batch_id": null,
  "error": null,
  "created_at": "2026-10-06T08:15:30.000Z",
  "sent_at": null,
  "balance": 4995
}

Emails are sent from WeSend's shared domain. You set the sender name and the reply-to address.
html and text together may not exceed 256 KB. Beyond that the answer is 422 message_too_long.
Read the final status with GET /messages/{id}: sent or failed. A failed email is refunded.

Send to many addresses

POST/v1/email/bulk

Sends one email to up to 1,000 addresses. Each recipient gets a separate email and never sees the others.

The fields are those of /email, except that to is a list of addresses.

curl -X POST https://api.wesend.mn/v1/email/bulk \
  -H "Authorization: Bearer $WESEND_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "to": [
    "[email protected]",
    "[email protected]"
  ],
  "subject": "Шинэ бараа ирлээ",
  "html": "<p>Намрын цуглуулга худалдаанд гарлаа.</p>"
}'

Response202 Accepted

{
  "id": "5d2a7c1e-93b4-4f6a-8e0d-b1c2d3e4f5a6",
  "status": "processing",
  "channel": "email",
  "total": 2,
  "sent": 0,
  "failed": 0,
  "credits": 10,
  "created_at": "2026-10-06T08:15:30.000Z",
  "completed_at": null,
  "balance": 4985
}