Developer API · Crypto billing · Zero KYC

SMS API with Crypto

Q: What happens if my balance runs out?

The API will return an error stating insufficient balance. We never send on overdraft or allow negative balances.

Send text messages from your software, website, or backend. Pay with Bitcoin, USDT, Monero, and more. No ID verification needed.

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Quickstart

Send an SMS in 4 lines of code

Simple JSON over HTTPS. Works with any language.

POST https://gsm7.com/api/v1/sms/send

Header: Authorization: Bearer YOUR_API_KEY

curl -X POST https://gsm7.com/api/v1/sms/send \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "+14155552671",
    "from": "YOURBRAND",
    "message": "Your verification code is 482910"
  }'

import requests

res = requests.post(
    "https://gsm7.com/api/v1/sms/send",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={
        "to": "+14155552671",
        "from": "YOURBRAND",
        "message": "Your verification code is 482910"
    }
)
print(res.json())

const res = await fetch("https://gsm7.com/api/v1/sms/send", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    to: "+14155552671",
    from: "YOURBRAND",
    message: "Your verification code is 482910"
  })
});
const data = await res.json();
console.log(data);

$ch = curl_init('https://gsm7.com/api/v1/sms/send');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer YOUR_API_KEY',
        'Content-Type: application/json'
    ],
    CURLOPT_POSTFIELDS => json_encode([
        'to' => '+14155552671',
        'from' => 'YOURBRAND',
        'message' => 'Your verification code is 482910'
    ])
]);
$response = json_decode(curl_exec($ch), true);
curl_close($ch);

Request parameters

Field	Type	Required	Description
`to`	string or array	Required	Phone number with country code (e.g. `+14155552671`). For bulk, pass an array of numbers.
`message`	string	Required	The message text. 160 characters for standard text, 70 characters with emojis.
`from`	string	Optional	Sender name (up to 11 characters) or number (up to 15 digits). Defaults to `GSM7`.

Sample response

{
  "success": true,
  "message": "SMS sent.",
  "data": {
    "message_id": "gsm7_msg_8c1f0e2a9b7d4c6e5f10",
    "recipient": "+14155552671",
    "sender_id": "YOURBRAND",
    "segments": 1,
    "rate_per_segment": 0.0085,
    "total_cost": 0.0085,
    "status": "delivered",
    "remaining_balance": 28.9915
  }
}

Questions

Frequently asked questions

Quick answers for developers integrating our API.

How do I authenticate?

Send your API key in the Authorization header as Bearer YOUR_API_KEY. You get your key immediately after signup.

Can I send to multiple numbers at once?

Yes. Pass an array of numbers or a comma-separated list in the "to" field.

What happens if my balance runs out?

The API returns an error stating insufficient balance. We never send on overdraft or allow negative balances.