Inform users with SMS updates, confirmations and notifications

Fast and reliable SMS messaging for your application

  • Communication

API reference on SwaggerHub API reference on Postman


With the SMS API, anyone can build reliable SMS messaging services using our infrastructure. It is available as a free demo version too. Send some test SMS messages and experiment with the API before taking it into production. In your API Store account you can apply to take the SMS API into production.

Conceptual model

Conceptual model



SMS is an abbreviation of Short Message Service. It's a service on mobile phones to send and receive short messages.

API workflow

API workflow

Features and constraints


  • Send a text message to another mobile phone number.


  • No images can be send with sms.
  • Messages longer than 160 charachters will be send as multiple SMS messages.
  • With this API, messages can only be send to mobile phones registered in the Netherlands. So the country code is locked to +31.

Getting started

Setting up your third party accounts

Make sure you have a registered account on the API Store and created an application on the portal, to receive the associated client ID and secret. These are neccessary to request an access token. You will receive these after your app is approved on te API Store.


OAuth 2.0

For accessing and/or manipulating the resources, the client application (your application) needs to be granted permission to do so. The OAuth 2.0 standard defines a protocol that allows such third-party authorization through the use of access tokens. Access tokens are central in the protocol: those tokens, in the form of strings, are delivered by an authorization server (our authentication server) and they enable the client application to securely access protected data on behalf of the resource owner (the end-user). We use Client Credentials Grant which means the application makes the request to the authentication service by sending authorization credentials and the service responds with an access token among other useful information.

Get Access Token

Copy your app's credentials (Consumer Key & Consumer Secret) to be used in the Authentication requests below.

Authentication in SwaggerHub:

  1. Upon loading completed within SwaggerHub, look top right for the Authorize button and click it.
  2. In the form, fill in client_id and client_secret fields, using your app's credentials.
  3. Click Authorize.
  4. Now you are authorized to issue the requests provided.

Authentication in Postman:

  1. Select Get Access Token from the collection.
  2. Make sure the right Environment corresponding to the API is selected.
  3. Edit the environment variables client_id and client_secret, using your app's credentials.
  4. Check the response code and message.
  5. Press the Send button to get the access token.
  6. Now you are authorized to issue the other requests in the collection.

The authorization service returns a JSON message that contains the access_token field.

    "refresh_token_expires_in": "0",
    "api_product_list": "[xxxxxxx]",
    "api_product_list_json": [
        " xxxxxxx"
    "organization_name": "kpn",
    "developer_email": "",
    "token_type": "Bearer",
    "issued_at": "1521039195424",
    "client_id": "APP_CONSUMER_KEY",
    "access_token": "haf2SDl07E9N7RluNQ4kJ1TkGgso",
    "application_name": "6e38ed2d-48b1-4362-97d6-04254065d79c",
    "scope": "",
    "expires_in": "3599",
    "refresh_count": "0",
    "status": "approved"

How to...

Send SMS

Send an SMS by calling the POST /send endpoint of the SMS API in Swaggerhub or Postman.
Note: Keep in mind that messages can only be send to Dutch mobile phones (country code +31).

Create your payload for the request using below snippet:

    "messages": [
            "content": "Greetings from KPN!",
            "mobile_number": "+316********"
   "sender": "Demo App"


  1. Select POST /send.
  2. Click Try it out.
  3. Edit the body parameter by providing the payload snippet above. In the payload change the content, mobile_number and sender to your own good. Make sure the content-type is set to application/json.
  4. Click Execute.
  5. Check the response code and message.


  1. Select (POST) /send.
  2. In the Body section, set the type to raw and insert the payload snippet above. In the payload change the content, mobile_number and sender to your own good. Make sure the content-type is set to application/json.
  3. Click Send.
  4. Check the response code and message.

Result example:

  "document_id": "b4e905d4-774c-4c83-8360-01427e17a33a",
  "status": "OK"

Return codes

Code   Description
200   Success
201   Created
202   Accepted
302   Found. Link in location header
400   Bad request
401   Unauthorized
403   Forbidden
404   Not found
405   Method not allowed
412   Precondition failed
429   Too many requests
500   Internal server error
502   Bad gateway
503   Service unavailable

API versions

Version   Description
1.0   Initial version