Send SMS | QuantumTec API reference

POST request

POST request
Parameter	Description
`to`stringrequired	Recipient phone number, including the country code.
`from`stringrequired	Sender name or number.
`text`stringrequired	Message text.
`MessageId`stringoptional	Your message ID. Assigned automatically when omitted.

curl --request POST 'https://api.quantumtec.eu/v1/sms/single' \
  --header 'X-ApiKey: YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --header 'Accept: application/json' \
  --data '{
  "to": "37250000000",
  "from": "INFO",
  "text": "Test message"
}'

Response

Response
Parameter	Description
`messageId`string	Use this ID to request a delivery report.
`partIds`string[]	IDs of the SMS parts.
`sent`string	Sending time in UTC.

{
  "messageId": "19905880-9404-4686-a8af-54af8888b96d",
  "sent": "2026-09-01T10:00:01.000Z",
  "partIds": [
    "300000005"
  ]
}

GET alternative

This endpoint also accepts GET with X-ApiKey, To, From and Text in the URL query string. MessageId is optional. URL-encode all values; the response has the same shape.

curl --get 'https://api.quantumtec.eu/v1/sms/single' \
  --header 'Accept: application/json' \
  --data-urlencode 'X-ApiKey=YOUR_API_KEY' \
  --data-urlencode 'To=37250000000' \
  --data-urlencode 'From=INFO' \
  --data-urlencode 'Text=Test message'

Message length

The API v1 guide lists a maximum of 800 characters. It gives 160 Latin or 70 Cyrillic characters for a single SMS, and 153 or 67 per part for a multipart message. Each part is charged separately.