SMS Gateway (Send SMS via URL)
The SMS Gateway allows devices on the router's LAN to send SMS messages by making an HTTP GET or POST request to the router's SMS endpoint. The router validates the request and sends the message via its cellular modem and SIM.
Security note: HTTP GET requests place credentials and message content in the URL, which may be exposed in browser history, server logs, and proxy intermediaries. Always use HTTPS when sending requests, restrict gateway access to trusted LAN hosts, and avoid transmitting sensitive information in message text.
Enable the SMS Gateway
Location in WebUI: Services > SMS > SMS Gateway
- Log in to the WebUI at
http://192.168.8.1 - Navigate to Services > SMS > SMS Gateway
- Tick Enable
- Set a username and password for the SMS endpoint — these are separate from the WebUI admin credentials
- Click Save and Apply
| Services > SMS > SMS Gateway | |
| Enable | ✓ |
| Username | smsuser |
| Password | •••••••• |
| Save and Apply | |
Send an SMS via URL (GET method)
With the gateway enabled, any device on the LAN can trigger an SMS by making a GET request to the following endpoint:
https://192.168.8.1/cgi-bin/sms_send?username=<user>&password=<pass>&text=<message>&number=<phone>URL parameters
| Parameter | Description | Example |
|---|---|---|
username |
The username configured in the SMS Gateway settings | smsuser |
password |
The password configured in the SMS Gateway settings | abc123 |
text |
The SMS message body. URL-encode spaces as %20. Use %n to insert a line break within the message. |
Hello%20world |
number |
The recipient phone number in national or international format | 07700900123 |
Example requests
Send a single-line message:
https://192.168.8.1/cgi-bin/sms_send?username=smsuser&password=abc123&text=Hello%20world&number=07700900123Send a multi-line message using %n as a line break:
https://192.168.8.1/cgi-bin/sms_send?username=smsuser&password=abc123&text=Line%20one%nLine%20two&number=07700900123Read received SMS messages via URL
To retrieve all SMS messages currently stored on the router's SIM:
https://192.168.8.1/cgi-bin/sms_list?username=smsuser&password=abc123The response is returned as structured text or XML depending on firmware version.
POST method
The SMS Gateway also accepts HTTP POST requests to the same endpoint (/cgi-bin/sms_send). POST is preferred over GET where security is a concern, as parameters are not included in the URL and are therefore less likely to appear in logs. The same parameters apply — submit them in the POST body using standard application/x-www-form-urlencoded encoding.
Troubleshooting
| Issue | Resolution |
|---|---|
| Request returns an authentication error | Verify the username and password in the URL exactly match those configured in Services > SMS > SMS Gateway. These are not the WebUI admin credentials. |
| SMS not delivered | Confirm the router has an active cellular connection and the SIM has SMS capability enabled. Check signal strength at Status > Mobile. Some IoT/data-only SIMs do not support SMS. |
| Connection refused or timeout on the request | Ensure the request is made from a device on the router's LAN. The SMS Gateway endpoint is not accessible from the WAN by default. Verify the router IP is correct. |
| Special characters not appearing correctly in message | URL-encode all special characters. Spaces must be %20, ampersands %26, and so on. Use a URL encoder tool if needed. |