SMS APIs

Trigger SMS from your application

Connect CRMs, business applications and automated workflows to SMS4U with a flexible HTTPS API. Send SMS, receive delivery results and handle replies.

SMS APIs for New Zealand businesses

Connect your applications to SMS

SMS4U recommends the Flexi API for new integrations. It accepts familiar JSON fields and maps common alternatives into an SMS request, making it easier to connect existing systems without rewriting every field name.

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Flexible JSON fields

Use familiar names such as to, mobile, body and message.

Existing workflows

Connect CRMs, monitoring tools, forms and automations with fewer changes.

Results and replies

Receive delivery-status events and inbound SMS through webhooks.

How the SMS API works

Send a message from your application in three straightforward steps.

1

Set up your credentials

Create an API-enabled user and obtain the credential for your request.

2

Submit a JSON request

POST your recipient, sender and message over HTTPS to the Flexi API.

3

Track message results

Use result and inbound webhooks to keep your application up to date.

Authentication is required. Include Authorization: Basic [your jwt] with each API request. The Developers guide covers the v3.00 endpoint and response handling.

A simple JSON request

The Flexi API recognises common field names from existing systems, so you can send an SMS with a compact request body.

Use the fields you already know

Provide the recipient, sender and message body. Other supported aliases include destination, destination_number, content and text.

For the complete endpoint, authentication requirements, callback examples and response statuses, see the developer documentation.

Explore the API documentation
JSON request bodyapplication/json
{
  "to": "+6421000001",
  "from": "5555",
  "body": "Hello, this is a test."
}

Ready to integrate SMS?

Build messaging into your existing workflow