Integrating Telnxo SMS with Google Sheets

Google Sheets combined with Google Apps Script gives you a powerful, free automation platform that can send SMS messages via the Telnxo API directly from a spreadsheet. This is useful for sending bulk SMS to contacts in a sheet, building a simple SMS broadcast tool, or triggering SMS from a Google Form submission.

What You Can Build

• Bulk SMS broadcaster — list contacts and messages in a sheet; run the script to send SMS to all rows.
• Google Forms → SMS auto-reply — send a confirmation SMS to every form respondent automatically.
• Appointment reminder sender — loop through a sheet of bookings and send reminders a day before.
• Order status notifier — paste order updates into a sheet and send status SMS to each customer.

Prerequisites

• A Google account with access to Google Sheets and Google Apps Script.
• A Telnxo API key with sms:send scope.
• A registered Sender ID in Telnxo.
• Phone numbers in your sheet must be in E.164 format (+91XXXXXXXXXX).

Step 1 — Set Up Your Google Sheet

Create a new Google Sheet with the following column structure:

The Status column is written by the script after each send — showing Sent, Failed, or the error message. This prevents duplicate sends if you run the script multiple times.

Step 2 — Open Apps Script

1. In your Google Sheet, go to Extensions → Apps Script.
2. The Apps Script editor opens. Delete any default code in the editor.
3. Paste the following script:

// Telnxo SMS Sender — Google Apps Script
// Replace these values with your own
const TELNXO_API_KEY = 'YOUR_TELNXO_API_KEY';
const SENDER_ID      = 'YOURNAME';  // Your registered Sender ID
const SHEET_NAME     = 'Sheet1';    // The name of your sheet tab

function sendBulkSMS() {
  const sheet  = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(SHEET_NAME);
  const rows   = sheet.getLastRow();

  // Start from row 2 to skip header row
  for (let i = 2; i <= rows; i++) {
    const phone   = sheet.getRange(i, 2).getValue().toString().trim();
    const message = sheet.getRange(i, 3).getValue().toString().trim();
    const status  = sheet.getRange(i, 4).getValue().toString().trim();

    // Skip rows already sent or with missing data
    if (status === 'Sent' || !phone || !message) continue;

    const result = sendSMS(phone, message);
    sheet.getRange(i, 4).setValue(result);

    // Pause 200ms between sends to respect rate limits
    Utilities.sleep(200);
  }
}

function sendSMS(phone, message) {
  const url     = 'https://api.telnxo.com/v1/sms/send';
  const payload = JSON.stringify({ from: SENDER_ID, to: phone, message: message });

  const options = {
    method:      'post',
    contentType: 'application/json',
    headers:     { 'Authorization': 'Bearer ' + TELNXO_API_KEY },
    payload:     payload,
    muteHttpExceptions: true,
  };

  try {
    const response = UrlFetchApp.fetch(url, options);
    const code     = response.getResponseCode();
    const body     = JSON.parse(response.getContentText());

    if (code >= 200 && code < 300) {
      return 'Sent';
    } else {
      return 'Failed: ' + (body.message || code);
    }
  } catch (e) {
    return 'Error: ' + e.toString();
  }
}

Step 3 — Store Your API Key Securely

Hardcoding your API key in the script is acceptable for personal use but not for shared spreadsheets. For better security, use Apps Script Properties:

// Store key once via Script Properties
function storeApiKey() {
  PropertiesService.getScriptProperties()
    .setProperty('TELNXO_API_KEY', 'your_key_here');
}

// Read from Properties in your main script
const TELNXO_API_KEY = PropertiesService.getScriptProperties()
  .getProperty('TELNXO_API_KEY');

Run storeApiKey() once to save the key, then delete that function. The key is stored encrypted in Google's infrastructure and not visible in the script code.

Step 4 — Add a Custom Menu to Run the Script

function onOpen() {
  SpreadsheetApp.getUi()
    .createMenu('📱 Telnxo SMS')
    .addItem('Send SMS to All Rows', 'sendBulkSMS')
    .addToUi();
}

After saving and reloading the sheet, a 📱 Telnxo SMS menu appears in the Google Sheets toolbar. Click it and select Send SMS to All Rows to trigger the bulk send.

Step 5 — Automate via Google Forms (Optional)

To send an auto-reply SMS whenever a Google Form is submitted:

1. Link your Google Form to a Google Sheet (Form → Responses → Link to Sheets).
2. In Apps Script, set a trigger on the sheet:

function onFormSubmit(e) {
  const phone   = e.values[2]; // Adjust index to match your form's phone field
  const name    = e.values[1]; // Name field
  const message = 'Hi ' + name + ', we received your submission. We will contact you shortly.';
  sendSMS(phone, message);
}

3. Go to Triggers (clock icon) → Add Trigger → onFormSubmit → From spreadsheet → On form submit.
4. Now every form submission automatically triggers an SMS to the respondent.

Troubleshooting

Next Steps

• SMS Send API — endpoint reference
• API key security best practices
• Integrating with Zapier